A method and system for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller fan

Abstract

The present invention discloses a method and system for correcting wind tunnel test data of a scaled counter-rotating propeller test piece, comprising: obtaining a first full-size counter-rotating propeller propulsion efficiency after Reynolds number correction based on a similar Mach number; obtaining a second full-size counter-rotating propeller propulsion efficiency after Mach number correction based on a similar Reynolds number; performing Reynolds number correction on the wind tunnel test data of a scaled counter-rotating propeller test piece using a first tension coefficient correction coefficient, a first power coefficient correction coefficient and the first full-size counter-rotating propeller propulsion efficiency based on a dissimilarity between the Reynolds number and the Mach number, and obtaining a result of the Reynolds number correction; based on the result of the Reynolds number correction, performing Mach number correction on the wind tunnel test data of the scaled counter-rotating propeller test piece using a second tension coefficient correction coefficient, a second power coefficient correction coefficient and the second full-size counter-rotating propeller propulsion efficiency, and obtaining the corrected propulsion efficiency of the full-size counter-rotating propeller under real wind tunnel conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of counter-rotating propeller fan performance testing, and in particular to a method and system for correcting wind tunnel test data of a counter-rotating propeller fan scaled test piece. Background Art

[0002] A propfan engine is a high-subsonic gas turbine engine, where the power output of its power turbine is transferred through a speed reducer to drive counter-rotating propellers, generating thrust. It combines the technical advantages of both turboprop and turbofan engines. As the primary thrust generator in a propfan engine, the performance of the counter-rotating propeller is crucial to the engine. There are generally two approaches to verifying the performance of counter-rotating propellers. The first is flight testing with a full-scale counter-rotating propeller equipped with the engine. This can accurately measure the performance of the propeller, but is costly, time-consuming, and risky. Furthermore, due to engine space constraints, the placement of thrust and torque measurement equipment is difficult. The second approach is wind tunnel testing using a scaled-down test piece. Using the wind tunnel setup to control the incoming flow to simulate flight conditions can significantly reduce development costs and shorten development cycles. However, wind tunnel testing can fail to fully meet similarity criteria, and there can be significant performance discrepancies between the scaled-down test piece and the full-scale counter-rotating propeller.

[0003] For conventional low-speed propellers, since the flight speed is relatively low, the wind tunnel flow conditions are closer to the actual flight conditions. The main difference between the scaled test piece and the full-size propeller is the difference in characteristic size. The difference in characteristic size mainly affects the size of the Reynolds number. When the scale ratio is large, the Reynolds number of the scaled propeller is still within the self-modeling area, and the effect of scale on the propeller performance can be ignored; when the scale ratio is small, the Reynolds number of the scaled propeller is outside the self-modeling area, and the effect on the performance should not be ignored. At present, when conducting low-speed propeller wind tunnel tests in China, the influence of the Reynolds number is usually ignored, which will bring large errors to the test performance of the low-speed propeller.

[0004] The invention patent with the existing announcement number CN 110702363A and the patent name "Method for correcting high-altitude propeller wind tunnel test data based on the influence of Reynolds number" discloses a method for correcting high-altitude propeller wind tunnel test data. This method uses an exponential relationship to correct the power coefficient and thrust coefficient of the propeller test piece under different Reynolds numbers, and uses the corrected power coefficient and thrust coefficient to calculate the corrected propeller propulsion efficiency.

[0005] For counter-rotating propeller fans with high-speed flight Mach numbers, due to the high flight speed and large power requirements, they are limited by the wind tunnel scale, motor power and incoming flow conditions. The scale ratio often needs to be very small, and the altitude and incoming flow Mach number need to be lowered for testing. As a result, the test performance of the test piece cannot accurately reflect the actual performance of the full-size counter-rotating propeller fan. Summary of the Invention

[0006] The purpose of the present invention is to provide a method and system for correcting wind tunnel test data of a scaled counter-rotating propeller fan test piece, which is used to solve the mapping between the wind tunnel performance test data of the scaled counter-rotating propeller fan test piece and the performance of the full-size counter-rotating propeller fan; and through the correction method provided by the present invention, more accurate aerodynamic performance test data such as high-altitude propeller thrust coefficient, power coefficient and propulsion efficiency are obtained, thereby providing effective data support for the design of counter-rotating propeller fan propellers.

[0007] To achieve the above-mentioned purpose, the present invention provides a method for correcting wind tunnel test data of a scaled-scale test piece of a counter-rotating propeller fan, comprising:

[0008] Based on the similarity of Mach numbers, the first thrust coefficient correction factor and the first power coefficient correction factor of the scaled counter-rotating propeller fan and the full-scale counter-rotating propeller fan are obtained; based on the first thrust coefficient correction factor and the first power coefficient correction factor, the propulsion efficiency of the first full-scale counter-rotating propeller fan after Reynolds number correction is obtained;

[0009] Based on the similarity of Reynolds numbers, the second tension coefficient correction factor and the second power coefficient correction factor of the scaled counter-rotating propeller fan and the full-scale counter-rotating propeller fan are obtained; based on the second tension coefficient correction factor and the second power coefficient correction factor, the propulsion efficiency of the second full-scale counter-rotating propeller fan after Mach number correction is obtained;

[0010] Based on the case that both the Reynolds number and the Mach number are not similar, the first pull coefficient correction coefficient, the first power coefficient correction coefficient and the first full-scale contra-rotating propeller-fan propulsion efficiency are used to perform Reynolds number correction on the wind tunnel test data of the contra-rotating propeller-fan scale test piece, and the Reynolds number correction result is obtained; based on the Reynolds number correction result, the second pull coefficient correction coefficient, the second power coefficient correction coefficient and the second full-scale contra-rotating propeller-fan propulsion efficiency are used to perform Mach number correction on the wind tunnel test data of the contra-rotating propeller-fan scale test piece, that is, to obtain the corrected propulsion efficiency of the full-scale contra-rotating propeller fan under real wind tunnel conditions.

[0011] Furthermore, based on the condition that the Mach numbers are similar, the proportion of the Reynolds number of the scaled counter-rotating propeller test piece relative to the Reynolds number of the full-scale counter-rotating propeller is reduced, and based on the main parameters reflecting the characteristics of the counter-rotating propeller, the first tension coefficient correction factor and the first power coefficient correction factor are obtained;

[0012] According to the first pull coefficient correction coefficient and the first power coefficient correction coefficient, the propulsion efficiency of the first full-size counter-rotating propeller fan after Reynolds number correction is obtained.

[0013] Furthermore, based on the similarity of Mach numbers, the proportion of the Reynolds number of the scaled-down counter-rotating propeller fan test piece relative to the Reynolds number of the full-size counter-rotating propeller fan is reduced, specifically,

[0014] Based on the similarity of Mach numbers, the difference in Reynolds number between the scaled-scale test specimen of the counter-rotating propeller fan and the full-scale counter-rotating propeller fan is analyzed;

[0015] Analyze and select the proportion of the scaled-scale test piece of the counter-rotating propeller fan, consider the influence of the flight altitude, and reduce the proportion of the Reynolds number of the scaled-scale test piece of the counter-rotating propeller fan relative to the Reynolds number of the full-size counter-rotating propeller fan.

[0016] Furthermore, based on the main parameters reflecting the characteristics of the contra-rotating propeller fan, a first thrust coefficient and a first power coefficient are obtained, as well as a polynomial of the first thrust coefficient correction coefficient and a polynomial of the first power coefficient correction coefficient are obtained;

[0017] The tension coefficient characteristic points and power coefficient characteristic points of the full-scale counter-rotating propeller fan and the scaled test pieces of the counter-rotating propeller fan at different flight altitudes and different rotational speeds are obtained through numerical calculation, and a three-dimensional spatial surface is constructed. The polynomials of the first tension coefficient correction coefficient and the first power coefficient correction coefficient are substituted into the three-dimensional spatial surface to fit the first tension coefficient correction coefficient and the first power coefficient correction coefficient.

[0018] Based on the mathematical relationship between the thrust coefficient and the power coefficient, the first thrust coefficient correction factor and the first power coefficient correction factor are used to obtain the first full-scale counter-rotating propeller fan propulsion efficiency under similar Mach number conditions.

[0019] Furthermore, based on the main parameters reflecting the characteristics of the contra-rotating propeller fan, a first pull coefficient and a first power coefficient are obtained, as well as a polynomial of the first pull coefficient correction coefficient and a polynomial of the first power coefficient correction coefficient are obtained, specifically,

[0020] The main parameters reflecting the characteristics of the contra-rotating propeller fan include the advance ratio, the thrust coefficient, the power coefficient and the propulsion efficiency, and the mathematical relationship between the first thrust coefficient and the first power is obtained, as well as the polynomial of the first thrust coefficient correction coefficient and the polynomial of the first power coefficient correction coefficient are obtained respectively;

[0021] Assuming that the thrust coefficient of the first full-scale counter-rotating propeller under similar Mach numbers is C TQ,Re The tensile coefficient of the scaled test specimen of the first contrarotating propeller fan is C TS,Re , the first tension coefficient correction factor is A T,Re ;

[0022] The mathematical relationship of the first tension coefficient is obtained by the following formula:

[0023] C TQ,Re =A T,Re ×C TS,Re

[0024] Among them, C TQ,Rerepresents the Reynolds number corrected first full-scale counter-rotating propeller pull coefficient, TQ represents the pull of the full-scale counter-rotating propeller, Re represents the Reynolds number correction, A T,Re represents the correction factor of the first tension coefficient corrected by the Reynolds number, T represents the tension of the scaled test piece of the counter-rotating propeller fan and the full-scale counter-rotating propeller fan, C TS,Re represents the Reynolds number corrected tensile coefficient of the first contra-rotating propeller scale test specimen, and TS represents the tensile force of the contra-rotating propeller scale test specimen;

[0025] Assuming the first full-scale counter-rotating propeller fan power coefficient is C under similar Mach number conditions PQ,Re The power coefficient of the first contrarotating propeller scale test piece is C PS,Re , the first power coefficient correction coefficient is A P,Re :

[0026] The mathematical relationship for the first power coefficient is obtained by the following formula:

[0027] C PQ,Re =A P,Re ×C PS,Re

[0028] Among them, C PQ,Re Represents the Reynolds number corrected first full-scale counter-rotating propeller fan power coefficient, PQ represents the power of the full-scale counter-rotating propeller fan, Re represents the Reynolds number correction, A P,Re represents the first power coefficient correction factor of the Reynolds number correction, P represents the power of the scaled test piece and the full-scale counter-rotating propeller fan, C PS,Re represents the power coefficient of the first contra-rotating propeller scaled test specimen corrected by Reynolds number, and PS represents the power of the contra-rotating propeller scaled test specimen;

[0029] Assume that the first tension coefficient correction polynomial of Reynolds number correction is A T,Re ', the first power coefficient correction coefficient polynomial is A p,Re ';

[0030] The first tension coefficient correction coefficient polynomial is obtained by the following formula:

[0031]

[0032] Among them, A T,Re ' represents the first tension coefficient correction polynomial corrected by Reynolds number, T represents the tension of the scaled test specimen and the full-scale counter-rotating propeller, Re represents the Reynolds number correction, b1, b2, b3, b4, b5, b6 are coefficients, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test specimen of the counter-rotating propeller fan;

[0033] The first power factor correction coefficient polynomial is obtained by the following formula:

[0034]

[0035] Among them, A p,Re ' represents the polynomial of the first power coefficient correction coefficient of the Reynolds number correction, P represents the power of the scaled test piece and the full-scale counter-rotating propeller fan, Re represents the Reynolds number correction, a1, a2, a3, a4, a5, a6 are coefficients, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test piece of the counter-rotating propeller fan.

[0036] Furthermore, the polynomials of the first tension coefficient correction coefficient and the first power coefficient correction coefficient are substituted into the polynomials to perform fitting on the three-dimensional space curved surface, thereby obtaining the first tension coefficient correction coefficient and the first power coefficient correction coefficient;

[0037] The first tension coefficient correction factor is obtained by the following formula:

[0038]

[0039] Among them, A T,Re represents the first tension coefficient correction factor of the Reynolds number correction, T represents the tension of the scaled test piece of the counter-rotating propeller and the full-scale counter-rotating propeller, Re represents the Reynolds number correction, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test specimen of the counter-rotating propeller fan;

[0040] The first power factor correction factor is obtained by the following formula:

[0041]

[0042] Among them, A P,Re represents the first power coefficient correction factor of the Reynolds number correction, P represents the power of the scaled test piece and the full-scale counter-rotating propeller fan, Re represents the Reynolds number correction, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test piece of the counter-rotating propeller fan.

[0043] Furthermore, based on the mathematical relationship between the first thrust coefficient and the first power coefficient, the first thrust coefficient correction coefficient and the first power coefficient correction coefficient are used to obtain the first full-scale counter-rotating propeller fan propulsion efficiency under similar Mach number conditions, specifically,

[0044] Substituting the first thrust coefficient correction factor and the first power coefficient correction factor into the mathematical relationship between the first thrust coefficient and the first power coefficient, the first full-size counter-rotating propeller fan propulsion efficiency is obtained by the following formula:

[0045]

[0046] Among them, η Re represents the Reynolds number corrected first full-scale counter-rotating propeller propulsion efficiency, Re represents the Reynolds number correction, λ is the forward ratio, C TQ,Re represents the Reynolds number corrected first full-scale counter-rotating propeller thrust coefficient, TQ full-scale counter-rotating propeller thrust, C PQ,Re PQ represents the power coefficient of the first full-size counter-rotating propeller fan corrected by the Reynolds number, and Re represents the power of the full-size counter-rotating propeller fan.

[0047] Furthermore, based on the condition of similar Reynolds numbers, numerical simulation is performed to obtain the characteristics of the scaled-scale test specimen of the contra-rotating propeller under different incoming Mach numbers, and the mathematical relationship between the second tension coefficient and the second power coefficient is obtained, and a polynomial for the second tension coefficient correction coefficient and a polynomial for the second power coefficient correction coefficient are obtained;

[0048] The tension coefficient characteristic points and power coefficient characteristic points of the full-scale counter-rotating propeller fan and the scaled test pieces of the counter-rotating propeller fan at different flight altitudes and different rotational speeds are obtained through numerical calculation, and a three-dimensional spatial surface is constructed. The polynomials of the second tension coefficient correction coefficient and the second power coefficient correction coefficient are substituted into the three-dimensional spatial surface to fit the three-dimensional spatial surface, and the second tension coefficient correction coefficient and the second power coefficient correction coefficient are obtained.

[0049] Based on the mathematical relationship between the thrust coefficient and the power coefficient, the second thrust coefficient correction coefficient and the second power coefficient correction coefficient are used to obtain the propulsion efficiency of the second full-size counter-rotating propeller fan after Mach number correction.

[0050] Furthermore, based on the similarity of Reynolds numbers, specifically,

[0051] High-pressure atmospheric conditions are simulated to make the Reynolds number of the scaled-scale CRP test piece similar to that of the full-scale CRP.

[0052] Furthermore, the main parameters reflecting the characteristics of the contra-rotating propeller fan include the advance ratio, the thrust coefficient, the power coefficient and the propulsion efficiency, and the mathematical relationship between the second thrust coefficient and the second power is obtained, as well as the polynomial of the second thrust coefficient correction coefficient and the polynomial of the second power coefficient correction coefficient are obtained respectively;

[0053] Assuming that the thrust coefficient of the second full-scale counter-rotating propeller fan under similar Reynolds number is C TQ,Ma The power coefficient of the second contra-rotating propeller scale test piece is C TS,Ma, the second tension coefficient correction factor is A T,Ma ;

[0054] The mathematical relationship of the second tension coefficient is obtained by the following formula:

[0055] C TQ,Ma =A T,Ma ×C TS,Ma

[0056] Among them, C TQ,Ma The thrust coefficient of the second full-scale counter-rotating propeller fan corrected by Mach number, TQ is the thrust of the full-scale counter-rotating propeller fan, Ma represents the Mach number correction, A T,Ma represents the second tension coefficient correction factor for Mach number correction, T represents the tension of the scaled test piece and the full-scale counter-rotating propeller fan, C TS,Ma represents the power coefficient of the second contra-rotating propeller scale test piece corrected for Mach number, and TS represents the tension of the contra-rotating propeller scale test piece;

[0057] Assuming that the power coefficient of the second full-scale counter-rotating propeller fan under similar Reynolds number is C PQ,Ma The power coefficient of the second contra-rotating propeller scale test piece is C PS,Ma , the second power coefficient correction coefficient is A P,Ma ;

[0058] The mathematical relationship for the first power coefficient is obtained by the following formula:

[0059] C PQ,Ma =A P,Ma ×C PS,Ma

[0060] Among them, C PQ,Ma The second full-scale counter-rotating propeller fan power coefficient corrected for Mach number, PQ is the power of the full-scale counter-rotating propeller fan, Ma is the Mach number correction, A is P,Ma represents the second power coefficient correction factor of the Mach number correction, P represents the power of the scaled-down counter-rotating propeller fan and the full-scale counter-rotating propeller fan, C PS,Ma represents the power coefficient of the second contra-rotating propeller-fan scale test piece corrected by Mach number, and PS represents the power of the contra-rotating propeller-fan scale test piece.

[0061] Furthermore, substituting the second tension coefficient correction coefficient and the second power coefficient correction coefficient into the polynomial, respectively fitting the three-dimensional space surface to obtain the second tension coefficient correction coefficient and the second power coefficient correction coefficient;

[0062] The second tension coefficient correction factor is obtained by the following formula:

[0063]

[0064] Among them, A T,MaIt represents the second tension coefficient correction factor of Mach number correction, T represents the tension of the scaled test piece of the counter-rotating propeller fan and the full-scale counter-rotating propeller fan, Ma represents the Mach number correction, λ is the forward ratio, Ma Q It represents the Mach number of the incoming flow of the full-size counter-rotating propeller fan, Ma S It represents the incoming flow Mach number of the counter-rotating propeller scale test piece;

[0065] The second power factor correction factor is obtained by the following formula:

[0066]

[0067] Among them, A P,Ma It represents the second power coefficient correction factor of Mach number correction, P represents the power of the scaled test piece of the counter-rotating propeller fan and the full-scale counter-rotating propeller fan, Ma represents the Mach number correction, λ is the forward ratio, Ma Q It represents the Mach number of the incoming flow of the full-size counter-rotating propeller fan, Ma S It represents the incoming flow Mach number of the counter-rotating propeller scale test piece.

[0068] Furthermore, the second thrust coefficient correction factor and the second power coefficient correction factor are substituted into the mathematical relationship between the second thrust coefficient and the second power coefficient, and the propulsion efficiency of the second full-size counter-rotating propeller fan is obtained by the following formula:

[0069]

[0070] Among them, η Ma represents the Mach number corrected propulsion efficiency of the second full-scale counter-rotating propeller fan, λ is the forward ratio, C TQ,Ma The thrust coefficient of the second full-scale counter-rotating propeller fan corrected by Mach number, TQ is the thrust of the full-scale counter-rotating propeller fan, Ma represents the Mach number correction, C PQ,Ma It represents the Mach number corrected second full-size counter-rotating propfan power coefficient, PQ full-size counter-rotating propfan power.

[0071] Furthermore, based on the case where both the Reynolds number and the Mach number are not similar, the first pull coefficient correction coefficient and the first power coefficient correction coefficient are used to obtain the first full-scale contra-rotating propeller fan propulsion efficiency according to the first pull coefficient and the first power coefficient, and the wind tunnel test data of the contra-rotating propeller fan scaled test piece are corrected by Reynolds number to obtain the Reynolds number corrected result;

[0072] Based on the result of Reynolds number correction, the second pull coefficient correction coefficient and the second power coefficient correction coefficient are used. According to the second pull coefficient and the second power coefficient, the second full-scale counter-rotating propeller-fan propulsion efficiency is obtained. The wind tunnel test data of the counter-rotating propeller-fan scaled test piece is corrected by Mach number to obtain the result of Mach number correction, that is, the corrected propulsion efficiency of the full-scale counter-rotating propeller-fan under real wind tunnel conditions is obtained.

[0073] The present invention also provides a wind tunnel test data correction system for a scaled test piece of a counter-rotating propeller fan, comprising:

[0074] A Reynolds number correction unit is used to obtain a first tension coefficient correction factor and a first power coefficient correction factor of the scaled counter-rotating propeller fan and the full-scale counter-rotating propeller fan under similar Mach numbers, and obtain the propulsion efficiency of the first full-scale counter-rotating propeller fan after Reynolds number correction through the first tension coefficient correction factor and the first power coefficient correction factor;

[0075] A Mach number correction unit is used to obtain a second tension coefficient correction factor and a second power coefficient correction factor of the scaled counter-rotating propeller fan and the full-scale counter-rotating propeller fan under similar Reynolds numbers, and obtain the propulsion efficiency of the second full-scale counter-rotating propeller fan after Mach number correction through the second tension coefficient correction factor and the second power coefficient correction factor;

[0076] The total correction unit is used to perform Reynolds number correction on the wind tunnel test data of the contra-rotating propeller scale test piece using the first pull coefficient correction coefficient, the first power coefficient correction coefficient and the first full-scale contra-rotating propeller ...

[0077] Furthermore, the Reynolds number correction unit is further used to reduce the proportion of the Reynolds number of the scaled counter-rotating propeller test piece relative to the Reynolds number of the full-size counter-rotating propeller when the Mach numbers are similar;

[0078] The Reynolds number correction unit also obtains the first thrust coefficient correction coefficient and the first power coefficient correction coefficient based on the main parameters reflecting the characteristics of the counter-rotating propeller fan; and obtains the propulsion efficiency of the first full-size counter-rotating propeller fan after Reynolds number correction based on the first thrust coefficient correction coefficient and the first power coefficient correction coefficient.

[0079] Furthermore, the Reynolds number correction unit is also used to reduce the proportion of the Reynolds number of the scaled counter-rotating propeller test piece relative to the Reynolds number of the full-size counter-rotating propeller when the Mach number is similar. Specifically,

[0080] The Reynolds number correction unit is also used to analyze the difference in Reynolds number between the scaled test piece of the counter-rotating propeller fan and the full-size counter-rotating propeller fan when the Mach numbers are similar; analyze the proportion of the selected scaled test piece of the counter-rotating propeller fan, consider the influence of the flight altitude, and reduce the proportion of the Reynolds number of the scaled test piece of the counter-rotating propeller fan relative to the Reynolds number of the full-size counter-rotating propeller fan.

[0081] Furthermore, the Reynolds number correction unit also obtains a first tension coefficient and a first power coefficient based on main parameters reflecting the characteristics of the counter-rotating propeller fan, as well as a polynomial for the first tension coefficient correction coefficient and a polynomial for the first power coefficient correction coefficient; through numerical calculation, tension coefficient characteristic points and power coefficient characteristic points of the full-size counter-rotating propeller fan and the counter-rotating propeller fan scaled test pieces at different flight altitudes and different speeds are obtained, and a three-dimensional spatial surface is constructed. The polynomials of the first tension coefficient correction coefficient and the first power coefficient correction coefficient are substituted into the three-dimensional spatial surface to fit the three-dimensional spatial surface, thereby obtaining the first tension coefficient correction coefficient and the first power coefficient correction coefficient;

[0082] The Reynolds number correction unit also obtains the first full-size counter-rotating propeller fan propulsion efficiency under similar Mach number conditions based on the mathematical relationship between the thrust coefficient and the power coefficient using the first thrust coefficient correction coefficient and the first power coefficient correction coefficient.

[0083] Furthermore, the Mach number correction unit also numerically simulates the characteristics of the scaled test piece of the counter-rotating propeller fan under different incoming Mach numbers under similar Reynolds numbers, obtains a mathematical relationship between the second tension coefficient and the second power coefficient, and obtains a polynomial of the second tension coefficient correction coefficient and a polynomial of the second power coefficient correction coefficient; through numerical calculation, the tension coefficient characteristic points and the power coefficient characteristic points of the full-size counter-rotating propeller fan and the scaled test piece of the counter-rotating propeller fan at different flight altitudes and different speeds are obtained, and a three-dimensional spatial surface is constructed. The polynomials of the second tension coefficient correction coefficient and the second power coefficient correction coefficient are substituted into the three-dimensional spatial surface to fit the three-dimensional spatial surface, and the second tension coefficient correction coefficient and the second power coefficient correction coefficient are obtained.

[0084] The Mach number correction unit also obtains the propulsion efficiency of the second full-size counter-rotating propeller fan after Mach number correction using a second thrust coefficient correction coefficient and a second power coefficient correction coefficient according to a mathematical relationship between the thrust coefficient and the power coefficient.

[0085] Furthermore, when the Reynolds number and the Mach number are not similar, the total correction unit uses the first pull coefficient correction coefficient and the first power coefficient correction coefficient to obtain the first full-scale counter-rotating propeller fan propulsion efficiency according to the first pull coefficient and the first power coefficient, and performs Reynolds number correction on the wind tunnel test data of the counter-rotating propeller fan scaled test piece to obtain a Reynolds number corrected result;

[0086] The result of the Reynolds number correction of the total correction unit is used. The second pull coefficient correction coefficient and the second power coefficient correction coefficient are used to obtain the second full-size counter-rotating propeller fan propulsion efficiency according to the second pull coefficient and the second power coefficient. The Mach number correction is performed on the wind tunnel test data of the counter-rotating propeller fan scaled test piece to obtain the result of the Mach number correction, that is, the corrected propulsion efficiency of the full-size counter-rotating propeller fan under real wind tunnel conditions is obtained.

[0087] The technical effects and advantages of the present invention are as follows: 1. The present invention proposes three methods: Method 1 is a Reynolds number correction method for the thrust coefficient, power coefficient and propulsion efficiency of counter-rotating propellers based on similar Mach numbers, that is, a polynomial method is used to describe the correction coefficients of the thrust coefficient and power coefficient, and the corrected thrust coefficient and power coefficient are used to calculate the propulsion efficiency of full-size counter-rotating propellers under similar Mach number conditions. Method 2 is a Mach number correction method for the thrust coefficient, power coefficient and propulsion efficiency of counter-rotating propellers based on similar Reynolds numbers, that is, a polynomial method is used to describe the correction coefficients of the thrust coefficient and power coefficient, and the corrected thrust coefficient and power coefficient are used to calculate the propulsion efficiency of full-size counter-rotating propellers under similar Reynolds number conditions; Method 3 is a method of first correcting the Reynolds number and then correcting the Mach number to obtain the corrected propulsion efficiency of full-size counter-rotating propellers under real wind tunnel conditions under conditions where both the Reynolds number and the Mach number are not similar. The correction method provided by the present invention can obtain more accurate aerodynamic performance test data such as high-altitude propeller thrust coefficient, power coefficient and propulsion efficiency, thereby providing effective data support for the design of counter-rotating propellers.

[0088] 2. The present invention realizes the mapping of the performance relationship between the scaled test piece and the full-size counter-rotating propeller fan in the case of a small scale ratio in the counter-rotating propeller fan wind tunnel test and the need to reduce the altitude and the incoming flow Mach number for the wind blowing test. When the scale of the scaled test piece is small, the Reynolds number of the scaled propeller is outside the self-modeling area. By calculating the performance parameters of the full-size counter-rotating propeller fan and the counter-rotating propeller fan scaled test piece to form a three-dimensional space surface and simulate it, the corrected coefficient is obtained to avoid the large error in the low-speed propeller test due to ignoring the influence of the Reynolds number. A correction method between the test characteristics of the counter-rotating propeller fan scaled test piece and the full-size counter-rotating propeller fan under real wind tunnel conditions is established, thereby providing effective data support for the design of counter-rotating propellers.

[0089] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 This is a flow chart of a method for correcting wind tunnel test data of a counter-rotating propeller fan scale test piece according to an embodiment of the present invention;

[0091] Figure 2 Schematic diagram of the structure of a wind tunnel test data correction system for a scaled-scale test piece of a counter-rotating propeller fan according to an embodiment of the present invention;

[0092] Figure 3A comparison chart of propulsion efficiency correction results of scaled test pieces simulating different flight altitudes under similar Mach number conditions in an embodiment of the present invention;

[0093] Figure 4 A comparison chart of propulsion efficiency correction results of a scaled-down test piece simulating different incoming flow Mach numbers under similar Reynolds number conditions in an embodiment of the present invention;

[0094] Figure 5 2 is a comparison chart of the propulsion efficiency correction results of the scaled test piece under the real wind tunnel flow conditions in an embodiment of the present invention. DETAILED DESCRIPTION

[0095] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0096] In order to address the deficiencies of the prior art, the present invention discloses a method and system for correcting wind tunnel test data of a scaled test piece of a contra-rotating propeller fan.

[0097] The present invention provides a method for correcting wind tunnel test data of a scaled counter-rotating propeller fan test piece, the process steps of which are as follows: Figure 1 As shown,

[0098] Based on the similarity of Mach numbers, the first thrust coefficient correction coefficient and the first power coefficient correction coefficient of the scaled counter-rotating propeller fan and the full-scale counter-rotating propeller fan are obtained; according to the first thrust coefficient correction coefficient and the first power coefficient correction coefficient, the propulsion efficiency of the first full-scale counter-rotating propeller fan after Reynolds number correction is obtained.

[0099] Specifically, based on the condition that the Mach numbers are similar, the proportion of the Reynolds number of the scaled counter-rotating propeller test piece relative to the Reynolds number of the full-size counter-rotating propeller is reduced, and based on the main parameters reflecting the characteristics of the counter-rotating propeller, the first tension coefficient correction factor and the first power coefficient correction factor are obtained;

[0100] According to the first pull coefficient correction coefficient and the first power coefficient correction coefficient, the propulsion efficiency of the first full-size counter-rotating propeller fan after Reynolds number correction is obtained.

[0101] Specifically, under the premise of ensuring the similarity of the incoming flow Mach number, the difference in Reynolds number between the scaled-down test piece of the counter-rotating propeller fan and the full-size counter-rotating propeller fan is analyzed; since counter-rotating propeller fans are usually suitable for high-power engines and are relatively large in size, and wind tunnel tests are affected by their scale and motor power, it is usually necessary to select a scale ratio of 1 / 5 or even smaller to reduce the Reynolds number. At the same time, after selecting the scale ratio, the influence of flight altitude must also be considered. Propeller fan engines usually fly at an altitude of 8 to 10 km or even higher, where the air pressure and temperature are low. Sometimes wind tunnels cannot simulate these atmospheric conditions, and tests need to be conducted using atmospheric conditions at a lower altitude. The flight altitude affects the air density, which will slightly increase the Reynolds number. Overall, the Reynolds number is usually reduced to 1 / 4 to 1 / 3 of the full-size state.

[0102] Based on the main parameters reflecting the characteristics of the counter-rotating propeller fan, a first thrust coefficient and a first power coefficient are obtained, as well as a polynomial of the first thrust coefficient correction coefficient and a polynomial of the first power coefficient correction coefficient are obtained; among which, the main parameters reflecting the characteristics of the counter-rotating propeller fan include forward ratio, thrust coefficient, power coefficient and propulsion efficiency.

[0103] Specifically, assuming that the thrust coefficient of the first full-scale counter-rotating propeller fan is C under similar Mach numbers, TQ,Re The tensile coefficient of the scaled test specimen of the first contrarotating propeller fan is C TS,Re , the first tension coefficient correction factor is A T,Re ;

[0104] The mathematical relationship of the first tension coefficient is obtained by the following formula:

[0105] C TQ,Re =A T,Re ×C TS,Re

[0106] Among them, C TQ,Re represents the Reynolds number corrected first full-scale counter-rotating propeller pull coefficient, TQ represents the pull of the full-scale counter-rotating propeller, Re represents the Reynolds number correction, A T,Re represents the correction factor of the first tension coefficient corrected by the Reynolds number, T represents the tension of the scaled test piece of the counter-rotating propeller fan and the full-scale counter-rotating propeller fan, C TS,Re represents the tensile coefficient of the scaled test specimen of the first contra-rotating propeller corrected by the Reynolds number, and TS represents the tensile force of the scaled test specimen of the contra-rotating propeller.

[0107] Assuming the first full-scale counter-rotating propeller fan power coefficient is C under similar Mach number conditions PQ,Re The power coefficient of the first contrarotating propeller scale test piece is C PS,Re , the first power coefficient correction coefficient is A P,Re :

[0108] The mathematical relationship for the first power coefficient is obtained by the following formula:

[0109] C PQ,Re =A P,Re ×C PS,Re

[0110] Among them, C PQ,Re Represents the Reynolds number corrected first full-scale counter-rotating propeller fan power coefficient, PQ represents the power of the full-scale counter-rotating propeller fan, Re represents the Reynolds number correction, A P,Re represents the first power coefficient correction factor of the Reynolds number correction, P represents the power of the scaled test piece and the full-scale counter-rotating propeller fan, C PS,Re represents the power coefficient of the first contra-rotating propeller-fan scaled test piece corrected by the Reynolds number, and PS represents the power of the contra-rotating propeller-fan scaled test piece.

[0111] Assume that the first tension coefficient correction coefficient polynomial for Reynolds number correction is AT,Re', and the first power coefficient correction coefficient polynomial is A p,Re ';

[0112] Assume that the first tension coefficient correction polynomial of Reynolds number correction is A T,Re ', the first power coefficient correction coefficient polynomial is A p,Re ';

[0113] The first tension coefficient correction coefficient polynomial is obtained by the following formula:

[0114]

[0115] Among them, A T,Re ' represents the first tension coefficient correction polynomial corrected by Reynolds number, T represents the tension of the scaled test specimen and the full-scale counter-rotating propeller, Re represents the Reynolds number correction, b1, b2, b3, b4, b5, b6 are coefficients, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test piece of the counter-rotating propeller fan.

[0116] The first power factor correction coefficient polynomial is obtained by the following formula:

[0117]

[0118] Among them, A p,Re ' represents the polynomial of the first power coefficient correction coefficient of the Reynolds number correction, P represents the power of the scaled test piece and the full-scale counter-rotating propeller fan, Re represents the Reynolds number correction, a1, a2, a3, a4, a5, a6 are coefficients, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test piece of the counter-rotating propeller fan.

[0119] The tension coefficient characteristic points and power coefficient characteristic points of the full-scale counter-rotating propeller fan and the scaled test pieces of the counter-rotating propeller fan at different flight altitudes and different rotational speeds are obtained through numerical calculation. These characteristic points constitute a three-dimensional spatial surface. The polynomials of the first tension coefficient correction coefficient and the first power coefficient correction coefficient are substituted into the three-dimensional spatial surface to fit the first tension coefficient correction coefficient and the first power coefficient correction coefficient.

[0120] The first tension coefficient correction factor is obtained by the following formula:

[0121]

[0122] Among them, A TRe represents the first tension coefficient correction factor of the Reynolds number correction, T represents the tension of the scaled test piece of the counter-rotating propeller and the full-scale counter-rotating propeller, Re represents the Reynolds number correction, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test specimen of the counter-rotating propeller fan;

[0123] The first power factor correction factor is obtained by the following formula:

[0124]

[0125] Among them, A PRe represents the first power coefficient correction factor of the Reynolds number correction, P represents the power of the scaled test piece and the full-scale counter-rotating propeller fan, Re represents the Reynolds number correction, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test piece of the counter-rotating propeller fan.

[0126] Based on the first thrust coefficient and the first power coefficient, the first thrust coefficient correction coefficient and the first power coefficient correction coefficient are used to obtain the first full-size counter-rotating propeller fan propulsion efficiency under similar Mach number conditions.

[0127] Specifically, the first thrust coefficient correction factor and the first power coefficient correction factor are substituted into the mathematical relationship between the first thrust coefficient and the first power coefficient, and the first full-size counter-rotating propeller fan propulsion efficiency is obtained by the following formula:

[0128]

[0129] Among them, η Re represents the Reynolds number corrected first full-scale counter-rotating propeller propulsion efficiency, Re represents the Reynolds number correction, λ is the forward ratio, C TQ,Re represents the Reynolds number corrected first full-scale counter-rotating propeller thrust coefficient, TQ full-scale counter-rotating propeller thrust, C PQ,RePQ represents the power coefficient of the first full-size counter-rotating propeller fan corrected by the Reynolds number, and Re represents the power of the full-size counter-rotating propeller fan.

[0130] like Figure 3 As shown in the figure, the wind tunnel test data correction method of the present invention for a scaled-down CRP fan test piece was numerically simulated and verified on a CRP fan test piece, which was 1 / 7 smaller than a full-size CRP fan, proving the feasibility of the method.

[0131] Depend on Figure 3 It can be seen that under similar Mach number conditions, the propulsion efficiency correction results of the scaled test piece simulating different flight altitudes show that the characteristics of the scaled counter-rotating propeller fan after Reynolds number correction are basically consistent with the characteristics of the full-size counter-rotating propeller fan.

[0132] Based on the similarity of Reynolds numbers, the second thrust coefficient correction coefficient and the second power coefficient correction coefficient of the scaled counter-rotating propeller fan and the full-scale counter-rotating propeller fan are obtained; according to the second thrust coefficient correction coefficient and the second power coefficient correction coefficient, the propulsion efficiency of the second full-scale counter-rotating propeller fan after Mach number correction is obtained.

[0133] Specifically, high-pressure atmospheric conditions were simulated to make the Reynolds number of the scaled-down CRP fan similar to that of the full-scale CRP fan. Based on the similar Reynolds number, the numerical simulation obtained the characteristics of the CRP fan under different incoming flow Mach numbers. The same method as above was used to perform Mach number corrections on the second thrust coefficient and the second power coefficient of the scaled-down test piece and the full-scale CRP fan:

[0134] Based on the characteristics of a counter-rotating propeller fan at different incoming Mach numbers, a mathematical relationship between the second thrust coefficient and the second power coefficient is obtained, and a polynomial for the second thrust coefficient correction factor and the second power coefficient correction factor are obtained. The main parameters reflecting the characteristics of a counter-rotating propeller fan include forward ratio, thrust coefficient, power coefficient, and propulsion efficiency.

[0135] Specifically, assuming that the thrust coefficient of the second full-scale counter-rotating propeller fan under similar Reynolds numbers is C TQ,Ma The power coefficient of the second contra-rotating propeller scale test piece is C TS,Ma , the second tension coefficient correction factor is A T,Ma ;

[0136] The mathematical relationship of the second tension coefficient is obtained by the following formula:

[0137] C TQ,Ma =A T,Ma ×C TS,Ma

[0138] Among them, C TQ,MaThe thrust coefficient of the second full-scale counter-rotating propeller fan corrected by Mach number, TQ is the thrust of the full-scale counter-rotating propeller fan, Ma represents the Mach number correction, A T,Ma represents the second tension coefficient correction factor for Mach number correction, T represents the tension of the scaled test piece and the full-scale counter-rotating propeller fan, C TS,Ma represents the power coefficient of the second contra-rotating propeller-fan scale test piece corrected by Mach number, and TS represents the tension of the contra-rotating propeller-fan scale test piece.

[0139] Assuming that the power coefficient of the second full-scale counter-rotating propeller fan under similar Reynolds number is C PQ,Ma The power coefficient of the second contra-rotating propeller scale test piece is C PS,Ma , the second power coefficient correction coefficient is A P,Ma ;

[0140] The mathematical relationship for the first power coefficient is obtained by the following formula:

[0141] C PQ,Ma =A P,Ma ×C PS,Ma

[0142] Among them, C PQ,Ma The second full-scale counter-rotating propeller fan power coefficient corrected for Mach number, PQ is the power of the full-scale counter-rotating propeller fan, Ma is the Mach number correction, A is P,Ma represents the second power coefficient correction factor of the Mach number correction, P represents the power of the scaled-down counter-rotating propeller fan and the full-scale counter-rotating propeller fan, C PS,Ma represents the power coefficient of the second contra-rotating propeller-fan scale test piece corrected by Mach number, and PS represents the power of the contra-rotating propeller-fan scale test piece.

[0143] Through numerical calculation, the tension coefficient characteristic points and power coefficient characteristic points of the full-size counter-rotating propeller fan and the scaled test pieces of the counter-rotating propeller fan at different flight altitudes and different rotation speeds are obtained, and a three-dimensional spatial surface is constructed; the polynomials of the second tension coefficient correction coefficient and the second power coefficient correction coefficient are substituted into the three-dimensional spatial surface to fit the second tension coefficient correction coefficient and the second power coefficient correction coefficient.

[0144] Specifically, substituting the second tension coefficient correction coefficient and the second power coefficient correction coefficient into the polynomials, respectively fitting the three-dimensional space surface to obtain the second tension coefficient correction coefficient and the second power coefficient correction coefficient;

[0145] The second tension coefficient correction factor is obtained by the following formula:

[0146]

[0147] Among them, A T,MaIt represents the second tension coefficient correction factor of Mach number correction, T represents the tension of the scaled test piece of the counter-rotating propeller fan and the full-scale counter-rotating propeller fan, Ma represents the Mach number correction, λ is the forward ratio, Ma Q It represents the Mach number of the incoming flow of the full-size counter-rotating propeller fan, Ma S It represents the incoming flow Mach number of the counter-rotating propeller scale test piece.

[0148] The second power factor correction factor is obtained by the following formula:

[0149]

[0150] Among them, A P,Ma It represents the second power coefficient correction factor of Mach number correction, P represents the power of the scaled test piece of the counter-rotating propeller fan and the full-scale counter-rotating propeller fan, Ma represents the Mach number correction, λ is the forward ratio, Ma Q It represents the Mach number of the incoming flow of the full-size counter-rotating propeller fan, Ma S It represents the incoming flow Mach number of the counter-rotating propeller scale test piece.

[0151] Based on the mathematical relationship between the thrust coefficient and the power coefficient, the second thrust coefficient correction coefficient and the second power coefficient correction coefficient are used to obtain the propulsion efficiency of the second full-size counter-rotating propeller fan after Mach number correction.

[0152] Substituting the second thrust coefficient correction factor and the second power coefficient correction factor into the mathematical relationship between the second thrust coefficient and the second power coefficient, the propulsion efficiency of the second full-size counter-rotating propeller fan is obtained by the following formula:

[0153]

[0154] Among them, η Ma represents the Mach number corrected propulsion efficiency of the second full-scale counter-rotating propeller fan, λ is the forward ratio, C TQ,Ma The thrust coefficient of the second full-scale counter-rotating propeller fan corrected by Mach number, TQ is the thrust of the full-scale counter-rotating propeller fan, Ma represents the Mach number correction, C PQ,Ma It represents the Mach number corrected second full-size counter-rotating propfan power coefficient, PQ full-size counter-rotating propfan power.

[0155] like Figure 4 It can be seen that under similar Reynolds number conditions, the propulsion efficiency correction results of the scaled test piece simulating different incoming flow Mach numbers show that the characteristics of the scaled counter-rotating propeller fan after Mach number correction are basically consistent with the characteristics of the full-scale counter-rotating propeller fan.

[0156] Based on the case that both the Reynolds number and the Mach number are not similar, the first pull coefficient correction coefficient, the first power coefficient correction coefficient and the first full-scale contra-rotating propeller-fan propulsion efficiency are used to perform Reynolds number correction on the wind tunnel test data of the contra-rotating propeller-fan scale test piece, and the Reynolds number correction result is obtained; based on the Reynolds number correction result, the second pull coefficient correction coefficient, the second power coefficient correction coefficient and the second full-scale contra-rotating propeller-fan propulsion efficiency are used to perform Mach number correction on the wind tunnel test data of the contra-rotating propeller-fan scale test piece, that is, to obtain the corrected propulsion efficiency of the full-scale contra-rotating propeller fan under real wind tunnel conditions.

[0157] Specifically, based on the situation where both the Reynolds number and the Mach number are not similar, the first pull coefficient correction coefficient and the first power coefficient correction coefficient are used to obtain the first full-scale counter-rotating propeller fan propulsion efficiency according to the first pull coefficient and the first power coefficient, and the Reynolds number correction is performed on the wind tunnel test data of the counter-rotating propeller fan scaled test piece to obtain the Reynolds number correction result;

[0158] Based on the result of Reynolds number correction, the second pull coefficient correction coefficient and the second power coefficient correction coefficient are used. According to the second pull coefficient and the second power coefficient, the second full-scale counter-rotating propeller-fan propulsion efficiency is obtained. The wind tunnel test data of the counter-rotating propeller-fan scaled test piece is corrected by Mach number to obtain the result of Mach number correction, that is, the corrected propulsion efficiency of the full-scale counter-rotating propeller-fan under real wind tunnel conditions is obtained.

[0159] like Figure 5 As shown in the figure, for the real wind tunnel test, the incoming flow condition of 0.55 Mach number at 2km altitude is used to simulate the incoming flow condition of 0.72 Mach number at 10km altitude. The Reynolds number and Mach number are not similar. The correction results of the propulsion efficiency of the scaled test piece are: Figure 5 It can be seen that the characteristics of the scaled test piece of the counter-rotating propeller fan after the Reynolds number and Mach number are corrected are basically consistent with the characteristics of the full-scale counter-rotating propeller fan.

[0160] The present invention also provides a wind tunnel test data correction system for a scaled-scale test piece of a counter-rotating propeller fan, the structural diagram of which is shown in FIG. Figure 2 As shown, it includes Reynolds number correction unit, Mach number correction unit and total correction unit.

[0161] The Reynolds number correction unit is used to obtain the first thrust coefficient correction coefficient and the first power coefficient correction coefficient of the scaled counter-rotating propeller fan and the full-scale counter-rotating propeller fan under similar Mach numbers, and obtain the first full-scale counter-rotating propeller fan propulsion efficiency after Reynolds number correction through the first thrust coefficient correction coefficient and the first power coefficient correction coefficient.

[0162] Specifically, the Reynolds number correction unit is also used to reduce the proportion of the Reynolds number of the scaled counter-rotating propeller test piece relative to the Reynolds number of the full-size counter-rotating propeller when the Mach numbers are similar.

[0163] The Reynolds number correction unit also obtains the first thrust coefficient correction coefficient and the first power coefficient correction coefficient based on the main parameters reflecting the characteristics of the counter-rotating propeller fan; and obtains the propulsion efficiency of the first full-size counter-rotating propeller fan after Reynolds number correction based on the first thrust coefficient correction coefficient and the first power coefficient correction coefficient.

[0164] Specifically, the Reynolds number correction unit is also used to analyze the difference in Reynolds number between the scaled test piece of the counter-rotating propeller fan and the full-size counter-rotating propeller fan when the Mach numbers are similar; analyze the proportion of the selected scaled test piece of the counter-rotating propeller fan, consider the influence of the flight altitude, and reduce the proportion of the Reynolds number of the scaled test piece of the counter-rotating propeller fan relative to the Reynolds number of the full-size counter-rotating propeller fan.

[0165] The Reynolds number correction unit also obtains the first thrust coefficient and the first power coefficient based on the main parameters reflecting the characteristics of the counter-rotating propeller fan, as well as the polynomial of the first thrust coefficient correction coefficient and the polynomial of the first power coefficient correction coefficient; the thrust coefficient characteristic points and the power coefficient characteristic points of the full-size counter-rotating propeller fan and the counter-rotating propeller fan scaled test pieces at different flight altitudes and different rotation speeds are obtained through numerical calculation, and a three-dimensional space surface is constructed, and the polynomials of the first thrust coefficient correction coefficient and the first power coefficient correction coefficient are substituted into the three-dimensional space surface to fit the first thrust coefficient correction coefficient and the first power coefficient correction coefficient; the Reynolds number correction unit also obtains the first full-size counter-rotating propeller fan propulsion efficiency under similar Mach number conditions based on the mathematical relationship between the thrust coefficient and the power coefficient using the first thrust coefficient correction coefficient and the first power coefficient correction coefficient.

[0166] The Mach number correction unit is used to obtain the second thrust coefficient correction coefficient and the second power coefficient correction coefficient of the scaled counter-rotating propeller fan and the full-scale counter-rotating propeller fan under similar Reynolds numbers, and obtain the propulsion efficiency of the second full-scale counter-rotating propeller fan after Mach number correction through the second thrust coefficient correction coefficient and the second power coefficient correction coefficient.

[0167] Specifically, the Mach number correction unit also obtains the characteristics of the scaled test piece of the counter-rotating propeller fan under different incoming Mach numbers through numerical simulation under the condition of similar Reynolds numbers, obtains the mathematical relationship between the second pull coefficient and the second power coefficient, and obtains the polynomial of the second pull coefficient correction coefficient and the polynomial of the second power coefficient correction coefficient; through numerical calculation, the pull coefficient characteristic points and power coefficient characteristic points of the full-size counter-rotating propeller fan and the scaled test piece of the counter-rotating propeller fan at different flight altitudes and different speeds are obtained, and a three-dimensional space surface is constructed, and the polynomials of the second pull coefficient correction coefficient and the second power coefficient correction coefficient are substituted into the three-dimensional space surface to fit the three-dimensional space surface respectively, and the second pull coefficient correction coefficient and the second power coefficient correction coefficient are obtained; the Mach number correction unit also obtains the propulsion efficiency of the second full-size counter-rotating propeller fan after Mach number correction by using the second pull coefficient correction coefficient and the second power coefficient correction coefficient according to the mathematical relationship between the pull coefficient and the power coefficient.

[0168] The total correction unit is used to perform Reynolds number correction on the wind tunnel test data of the contra-rotating propeller scale test piece using the first pull coefficient correction coefficient, the first power coefficient correction coefficient and the first full-scale contra-rotating propeller ...

[0169] Specifically, when the Reynolds number and the Mach number are not similar, the total correction unit uses the first pull coefficient correction coefficient and the first power coefficient correction coefficient to obtain the first full-size contra-rotating propeller fan propulsion efficiency according to the first pull coefficient and the first power coefficient, and performs Reynolds number correction on the wind tunnel test data of the contra-rotating propeller fan scale test piece to obtain the Reynolds number correction result; the total correction unit uses the second pull coefficient correction coefficient and the second power coefficient correction coefficient based on the Reynolds number correction result to obtain the second full-size contra-rotating propeller fan propulsion efficiency according to the second pull coefficient and the second power coefficient, and performs Mach number correction on the wind tunnel test data of the contra-rotating propeller fan scale test piece to obtain the Mach number correction result, that is, the corrected propulsion efficiency of the full-size contra-rotating propeller fan under real wind tunnel conditions is obtained.

[0170] Regarding the system in the above embodiment, the specific manner in which each module unit performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0171] The present invention realizes the mapping of the performance relationship between the scaled test piece and the full-size counter-rotating propeller fan in the case where the scale ratio is small and the height and the incoming flow Mach number need to be lowered to conduct the wind test in the counter-rotating propeller fan wind tunnel test. When the scale of the scaled test piece is small, the Reynolds number of the scaled propeller is outside the self-modeling area. By calculating the performance parameters of the full-size counter-rotating propeller fan and the counter-rotating propeller fan scaled test piece to form a three-dimensional space surface and simulate it, the corrected coefficient is obtained to avoid the large error in the low-speed propeller test due to ignoring the influence of the Reynolds number. A correction method is established between the test characteristics of the counter-rotating propeller fan scaled test piece and the full-size counter-rotating propeller fan under real wind tunnel conditions, thereby providing effective data support for the design of counter-rotating propeller fan propellers. A correction method can be established between the test characteristics of the counter-rotating propeller fan scaled test piece and the full-size counter-rotating propeller fan under real wind tunnel conditions, thereby providing effective data support for the design of counter-rotating propeller fan propellers.

[0172] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller fan, characterized in that: include: Based on the similarity of Mach numbers, the first tension coefficient correction factor and the first power coefficient correction factor of the scaled-scale test piece of the counter-rotating propeller fan and the full-size counter-rotating propeller fan are obtained; Obtaining a Reynolds number-corrected first full-size counter-rotating propeller fan propulsion efficiency according to a first thrust coefficient correction coefficient and a first power coefficient correction coefficient; Based on the similarity of Reynolds numbers, the second tension coefficient correction factor and the second power coefficient correction factor of the scaled-scale test piece of the counter-rotating propeller fan and the full-size counter-rotating propeller fan are obtained; According to the second thrust coefficient correction coefficient and the second power coefficient correction coefficient, the propulsion efficiency of the second full-size counter-rotating propeller fan after Mach number correction is obtained; Based on the fact that both the Reynolds number and the Mach number are not similar, the Reynolds number correction is performed on the wind tunnel test data of the scaled test piece of the contra-rotating propeller fan by using the first pull coefficient correction coefficient, the first power coefficient correction coefficient and the first full-size contra-rotating propeller fan propulsion efficiency to obtain the result of the Reynolds number correction; Based on the result of Reynolds number correction, the second pull coefficient correction coefficient, the second power coefficient correction coefficient and the second full-size CRP propulsion efficiency are used to make Mach number correction on the wind tunnel test data of the CRP scaled test piece, so as to obtain the corrected propulsion efficiency of the full-size CRP under real wind tunnel conditions.

2. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 1, characterized in that: Based on the similarity of Mach numbers, the proportion of the Reynolds number of the scaled counter-rotating propeller test piece to the Reynolds number of the full-size counter-rotating propeller is reduced, and the first tension coefficient correction factor and the first power coefficient correction factor are obtained based on the main parameters reflecting the characteristics of the counter-rotating propeller; According to the first pull coefficient correction coefficient and the first power coefficient correction coefficient, the propulsion efficiency of the first full-size counter-rotating propeller fan after Reynolds number correction is obtained.

3. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 2, characterized in that: Based on the similarity of Mach number, the proportion of the Reynolds number of the scaled test piece of the counter-rotating propeller fan to the Reynolds number of the full-size counter-rotating propeller fan is reduced, specifically, Based on the similarity of Mach numbers, the difference in Reynolds number between the scaled test specimen of the counter-rotating propeller fan and the full-size counter-rotating propeller fan is analyzed; Analyze and select the proportion of the scaled-scale test piece of the counter-rotating propeller fan, consider the influence of the flight altitude, and reduce the proportion of the Reynolds number of the scaled-scale test piece of the counter-rotating propeller fan relative to the Reynolds number of the full-size counter-rotating propeller fan.

4. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 2, characterized in that: Based on main parameters reflecting the characteristics of the counter-rotating propeller fan, a first thrust coefficient and a first power coefficient are obtained, as well as a polynomial of a first thrust coefficient correction coefficient and a polynomial of a first power coefficient correction coefficient are obtained; The tension coefficient characteristic points and power coefficient characteristic points of the full-size counter-rotating propeller fan and the scaled test pieces of the counter-rotating propeller fan at different flight altitudes and different rotation speeds are obtained through numerical calculation, and a three-dimensional space surface is formed. The polynomials of the first tension coefficient correction coefficient and the first power coefficient correction coefficient are substituted into the three-dimensional space surface to fit the first tension coefficient correction coefficient and the first power coefficient correction coefficient respectively, so as to obtain the first tension coefficient correction coefficient and the first power coefficient correction coefficient; Based on the mathematical relationship between the thrust coefficient and the power coefficient, the first thrust coefficient correction factor and the first power coefficient correction factor are used to obtain the first full-size counter-rotating propeller fan propulsion efficiency under similar Mach number conditions.

5. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 4, characterized in that: Based on the main parameters reflecting the characteristics of the counter-rotating propeller fan, a first pull coefficient and a first power coefficient are obtained, as well as a polynomial of a first pull coefficient correction coefficient and a polynomial of a first power coefficient correction coefficient are obtained, specifically, The main parameters reflecting the characteristics of the counter-rotating propeller fan include the advance ratio, the thrust coefficient, the power coefficient and the propulsion efficiency, and the mathematical relationship of the first thrust coefficient and the first power are obtained respectively, and the polynomial of the first thrust coefficient correction coefficient and the polynomial of the first power coefficient correction coefficient are obtained; Assuming that the thrust coefficient of the first full-scale counter-rotating propeller under similar Mach numbers is C TQ,Re The tensile coefficient of the first counter-rotating propeller scale test specimen is C TS,Re , the first tension coefficient correction factor is A T,Re ; The mathematical relationship of the first tension coefficient is obtained by the following formula: C TQ,Re =A T,Re ×C TS,Re Among them, C TQ,Re represents the Reynolds number corrected first full-size counter-rotating propeller pull coefficient, TQ represents the pull of the full-size counter-rotating propeller, Re represents the Reynolds number correction, A T,Re represents the correction factor of the first tension coefficient corrected by the Reynolds number, T represents the tension of the scaled test specimen of the counter-rotating propeller and the full-size counter-rotating propeller, C TS,Re represents the tension coefficient of the first contra-rotating propeller scaled test specimen corrected by the Reynolds number, and TS represents the tension of the contra-rotating propeller scaled test specimen; Assuming that the power coefficient of the first full-scale counter-rotating propeller fan under similar Mach numbers is C PQ,Re , the power coefficient of the first counter-rotating propeller scaled test specimen is C PS,Re , the first power factor correction factor is A P,Re : The mathematical relationship for the first power coefficient is obtained by: C PQ,Re =A P,Re ×C PS,Re Among them, C PQ,Re represents the Reynolds number corrected first full-size counter-rotating propeller power coefficient, PQ represents the power of the full-size counter-rotating propeller, Re represents the Reynolds number correction, A P,Re represents the first power coefficient correction factor of the Reynolds number correction, P represents the power of the scaled test specimen of the counter-rotating propeller fan and the full-size counter-rotating propeller fan, C PS,Re represents the power coefficient of the first contra-rotating propeller-fan scaled test piece corrected by Reynolds number, PS represents the power of the contra-rotating propeller-fan scaled test piece; Assume that the correction coefficient polynomial of the first tension coefficient corrected by Reynolds number is A T,Re ', the first power coefficient correction coefficient polynomial is A p,Re '; The first tension coefficient correction factor polynomial is obtained by the following formula: Among them, A T,Re ' represents the correction coefficient polynomial of the first tension coefficient corrected by Reynolds number, T represents the tension of the scaled test specimen of the counter-rotating propeller and the full-size counter-rotating propeller, Re represents the Reynolds number correction, b1, b2, b3, b4, b5, b6 are coefficients, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test specimen of the counter-rotating propeller; The first power factor correction coefficient polynomial is obtained by the following formula: Among them, A p,Re ' represents the polynomial of the first power coefficient correction coefficient of the Reynolds number correction, P represents the power of the scaled test piece of the counter-rotating propeller fan and the full-size counter-rotating propeller fan, Re represents the Reynolds number correction, a1, a2, a3, a4, a5, a6 are coefficients, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test piece of the counter-rotating propeller.

6. A method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 4 or 5, characterized in that: Substituting the first tension coefficient correction coefficient and the first power coefficient correction coefficient into the polynomial, respectively fitting the three-dimensional space surface, to obtain the first tension coefficient correction coefficient and the first power coefficient correction coefficient; The first tension coefficient correction factor is obtained by the following formula: Among them, A T,Re represents the correction factor of the first tension coefficient corrected by the Reynolds number, T represents the tension of the scaled test specimen of the counter-rotating propeller and the full-size counter-rotating propeller, Re represents the Reynolds number correction, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test specimen of the counter-rotating propeller; The first power factor correction factor is obtained by the following formula: Among them, A P,Re represents the first power coefficient correction factor of Reynolds number correction, P represents the power of the scaled test specimen of the counter-rotating propeller fan and the full-size counter-rotating propeller fan, Re represents the Reynolds number correction, λ is the forward ratio, Re Q is the Reynolds number of the full-size counter-rotating propeller, Re S is the Reynolds number of the scaled test piece of the counter-rotating propeller.

7. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 6, characterized in that: Based on the mathematical relationship between the first thrust coefficient and the first power coefficient, the first thrust coefficient correction coefficient and the first power coefficient correction coefficient are used to obtain the first full-size counter-rotating propeller fan propulsion efficiency under similar Mach number conditions, specifically, Substituting the first thrust coefficient correction factor and the first power coefficient correction factor into the mathematical relationship between the first thrust coefficient and the first power coefficient, the first full-size counter-rotating propeller fan propulsion efficiency is obtained by the following formula: Among them, η Re represents the Reynolds number corrected first full-scale counter-rotating propeller propulsion efficiency, Re represents the Reynolds number correction, λ is the forward ratio, C TQ,Re represents the Reynolds number corrected first full-scale counter-rotating propeller thrust coefficient, TQ full-scale counter-rotating propeller thrust, C PQ,Re PQ represents the power coefficient of the first full-size counter-rotating propeller fan corrected by the Reynolds number, and Re represents the Reynolds number correction.

8. A method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 1 or 7, characterized in that: Based on the similar Reynolds number, the characteristics of the scaled test piece of the counter-rotating propeller under different incoming flow Mach numbers are obtained by numerical simulation, the mathematical relationship between the second tension coefficient and the second power coefficient is obtained, and the polynomial of the second tension coefficient correction coefficient and the polynomial of the second power coefficient correction coefficient are obtained; The tension coefficient characteristic points and the power coefficient characteristic points of the full-size counter-rotating propeller fan and the scaled test pieces of the counter-rotating propeller fan at different flight altitudes and different rotation speeds are obtained through numerical calculation, and a three-dimensional space surface is formed. The polynomials of the second tension coefficient correction coefficient and the second power coefficient correction coefficient are substituted into the three-dimensional space surface to fit the second tension coefficient correction coefficient and the second power coefficient correction coefficient respectively, so as to obtain the second tension coefficient correction coefficient and the second power coefficient correction coefficient; Based on the mathematical relationship between the thrust coefficient and the power coefficient, the second thrust coefficient correction coefficient and the second power coefficient correction coefficient are used to obtain the propulsion efficiency of the second full-size counter-rotating propeller fan after Mach number correction.

9. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 8, characterized in that: Based on the similarity of Reynolds numbers, specifically, By simulating high-pressure atmospheric conditions, the Reynolds number of the scaled CRP test piece is made similar to that of the full-size CRP.

10. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 8, characterized in that: The main parameters reflecting the characteristics of the counter-rotating propeller fan include the advance ratio, the thrust coefficient, the power coefficient and the propulsion efficiency, and the mathematical relationship between the second thrust coefficient and the second power, as well as the polynomial of the second thrust coefficient correction coefficient and the polynomial of the second power coefficient correction coefficient are obtained respectively; Assuming that the thrust coefficient of the second full-size counter-rotating propeller under similar Reynolds number is C TQ,Ma , the power coefficient of the second contra-rotating propeller scaled test specimen is C TS,Ma , the second tension coefficient correction factor is A T,Ma ; The mathematical relationship of the second tension coefficient is obtained by the following formula: C TQ,Ma =A T,Ma ×C TS,Ma Among them, C TQ,Ma represents the Mach number corrected second full-size counter-rotating propeller thrust coefficient, TQ is the thrust of the full-size counter-rotating propeller, Ma represents the Mach number correction, A T,Ma represents the correction factor of the second tension coefficient for Mach number correction, T represents the tension of the scaled test specimen of the counter-rotating propeller and the full-scale counter-rotating propeller, C TS,Ma represents the power coefficient of the second contra-rotating propeller scale test piece corrected by Mach number, TS represents the tension of the contra-rotating propeller scale test piece; Assuming that the power coefficient of the second full-scale counter-rotating propeller fan under similar Reynolds number is C PQ,Ma , the power coefficient of the second contra-rotating propeller scaled test specimen is C PS,Ma , the second power factor correction factor is A P,Ma ; The mathematical relationship for the first power coefficient is obtained by: C PQ,Ma =A P,Ma ×C PS,Ma Among them, C PQ,Ma The second full-size counter-rotating propeller fan power coefficient corrected by Mach number, PQ is the power of the full-size counter-rotating propeller fan, Ma represents the Mach number correction, A P,Ma represents the second power coefficient correction factor of the Mach number correction, P represents the power of the scaled test specimen of the counter-rotating propeller fan and the full-size counter-rotating propeller fan, C PS,Ma represents the power coefficient of the second counter-rotating propeller-fan scale test piece corrected by Mach number, and PS represents the power of the counter-rotating propeller-fan scale test piece.

11. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 10, characterized in that: Substituting the second tension coefficient correction coefficient and the second power coefficient correction coefficient into the polynomials, respectively fitting the three-dimensional space curved surface, to obtain the second tension coefficient correction coefficient and the second power coefficient correction coefficient; The second tension coefficient correction factor is obtained by the following formula: Among them, A T,Ma represents the second tension coefficient correction factor for Mach number correction, T represents the tension of the scaled test specimen of the counter-rotating propeller fan and the full-size counter-rotating propeller fan, Ma represents the Mach number correction, λ is the forward ratio, Ma Q It represents the Mach number of the full-size counter-rotating propeller fan flow, Ma S It represents the incoming flow Mach number of the scaled test specimen of the counter-rotating propeller; The second power factor correction factor is obtained by the following formula: Among them, A P,Ma represents the second power coefficient correction factor of Mach number correction, P represents the power of the scaled test specimen of the counter-rotating propeller fan and the full-size counter-rotating propeller fan, Ma represents the Mach number correction, λ is the forward ratio, Ma Q It represents the Mach number of the full-size counter-rotating propeller fan flow, Ma S It represents the incoming flow Mach number of the scaled test specimen of the counter-rotating propeller.

12. The method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 11, characterized in that: Substituting the second thrust coefficient correction factor and the second power coefficient correction factor into the mathematical relationship between the second thrust coefficient and the second power coefficient, the propulsion efficiency of the second full-size counter-rotating propeller fan is obtained by the following formula: Among them, η Ma represents the Mach number corrected second full-scale counter-rotating propeller propulsion efficiency, λ is the forward ratio, C TQ,Ma represents the Mach number corrected second full-scale counter-rotating propeller thrust coefficient, TQ is the thrust of the full-scale counter-rotating propeller, Ma represents the Mach number correction, C PQ,Ma It represents the Mach number corrected second full-size counter-rotating propfan power coefficient, PQ full-size counter-rotating propfan power.

13. A method for correcting wind tunnel test data of a scaled test piece of a counter-rotating propeller according to claim 1 or 12, characterized in that: Based on the fact that both the Reynolds number and the Mach number are not similar, the first full-scale counter-rotating propeller fan propulsion efficiency is obtained according to the first pull coefficient and the first power coefficient by using the first pull coefficient correction coefficient and the first power coefficient, and the wind tunnel test data of the counter-rotating propeller fan scaled test piece are corrected by Reynolds number to obtain the result of Reynolds number correction; Based on the result of Reynolds number correction, the second pull coefficient correction coefficient and the second power coefficient correction coefficient are used, and according to the second pull coefficient and the second power coefficient, the second full-size counter-rotating propeller-fan propulsion efficiency is obtained. The wind tunnel test data of the counter-rotating propeller-fan scaled test piece is corrected by Mach number to obtain the result of Mach number correction, that is, the corrected propulsion efficiency of the full-size counter-rotating propeller-fan under real wind tunnel conditions is obtained.

14. A wind tunnel test data correction system for a scaled test piece of a counter-rotating propeller fan, characterized in that: include, A Reynolds number correction unit is used to obtain a first tension coefficient correction coefficient and a first power coefficient correction coefficient of a scaled counter-rotating propeller fan and a full-size counter-rotating propeller fan under similar Mach numbers, and obtain a first full-size counter-rotating propeller fan propulsion efficiency after Reynolds number correction through the first tension coefficient correction coefficient and the first power coefficient correction coefficient; A Mach number correction unit is used to obtain a second tension coefficient correction factor and a second power coefficient correction factor of a scaled counter-rotating propeller fan test piece and a full-size counter-rotating propeller fan under similar Reynolds numbers, and obtain a propulsion efficiency of a second full-size counter-rotating propeller fan after Mach number correction through the second tension coefficient correction factor and the second power coefficient correction factor; a total correction unit, for performing Reynolds number correction on the wind tunnel test data of the scaled test piece of the counter-rotating propeller fan by using the first drag coefficient correction coefficient, the first power coefficient correction coefficient and the first full-size counter-rotating propeller fan propulsion efficiency when the Reynolds number and the Mach number are not similar, so as to obtain a result of the Reynolds number correction; Based on the result of Reynolds number correction, the second pull coefficient correction coefficient, the second power coefficient correction coefficient and the second full-size CRP propulsion efficiency are used to make Mach number correction on the wind tunnel test data of the CRP scaled test piece, so as to obtain the corrected propulsion efficiency of the full-size CRP under real wind tunnel conditions.

15. The wind tunnel test data correction system for a scaled test piece of a counter-rotating propeller according to claim 14, characterized in that: The Reynolds number correction unit is also used to reduce the proportion of the Reynolds number of the scaled test piece of the counter-rotating propeller relative to the Reynolds number of the full-size counter-rotating propeller when the Mach numbers are similar; The Reynolds number correction unit further obtains the first tension coefficient correction coefficient and the first power coefficient correction coefficient according to the main parameters reflecting the characteristics of the counter-rotating propeller fan; According to the first pull coefficient correction coefficient and the first power coefficient correction coefficient, the propulsion efficiency of the first full-size counter-rotating propeller fan after Reynolds number correction is obtained.

16. The wind tunnel test data correction system for a scaled test piece of a counter-rotating propeller fan according to claim 15, characterized in that: The Reynolds number correction unit is also used to reduce the proportion of the Reynolds number of the scaled test piece of the counter-rotating propeller relative to the Reynolds number of the full-size counter-rotating propeller when the Mach number is similar. Specifically, The Reynolds number correction unit is also used to analyze the difference in Reynolds number between the scaled test piece of the counter-rotating propeller and the full-size counter-rotating propeller when the Mach numbers are similar; analyze and select the proportion of the scaled test piece of the counter-rotating propeller, consider the influence of the flight altitude, and reduce the proportion of the Reynolds number of the scaled test piece of the counter-rotating propeller relative to the Reynolds number of the full-size counter-rotating propeller.

17. A wind tunnel test data correction system for a scaled test piece of a counter-rotating propeller according to claim 15 or 16, characterized in that: The Reynolds number correction unit also obtains the first tension coefficient and the first power coefficient according to the main parameters reflecting the characteristics of the counter-rotating propeller fan, as well as the polynomial of the first tension coefficient correction coefficient and the polynomial of the first power coefficient correction coefficient; the tension coefficient characteristic points and the power coefficient characteristic points of the full-size counter-rotating propeller fan and the counter-rotating propeller fan scaled test pieces at different flight altitudes and different rotation speeds are obtained through numerical calculation, and a three-dimensional space surface is constructed, and the polynomials of the first tension coefficient correction coefficient and the first power coefficient correction coefficient are substituted into the three-dimensional space surface to fit the three-dimensional space surface, respectively, to obtain the first tension coefficient correction coefficient and the first power coefficient correction coefficient; The Reynolds number correction unit also obtains the propulsion efficiency of the first full-size counter-rotating propeller fan under similar Mach number conditions by using a first thrust coefficient correction coefficient and a first power coefficient correction coefficient based on a mathematical relationship between the thrust coefficient and the power coefficient.

18. The wind tunnel test data correction system for a scaled test piece of a counter-rotating propeller according to claim 14, characterized in that: The Mach number correction unit also numerically simulates the characteristics of the scaled test piece of the counter-rotating propeller fan under different incoming Mach numbers under the condition of similar Reynolds numbers, obtains the mathematical relationship between the second tension coefficient and the second power coefficient, and obtains the polynomial of the second tension coefficient correction coefficient and the polynomial of the second power coefficient correction coefficient; obtains the tension coefficient characteristic points and the power coefficient characteristic points of the full-size counter-rotating propeller fan and the scaled test piece of the counter-rotating propeller fan at different flight altitudes and different rotation speeds through numerical calculation, and forms a three-dimensional space surface, substitutes the polynomials of the second tension coefficient correction coefficient and the second power coefficient correction coefficient into the three-dimensional space surface for fitting, and obtains the second tension coefficient correction coefficient and the second power coefficient correction coefficient; The Mach number correction unit also obtains the propulsion efficiency of the second full-size counter-rotating propeller fan after Mach number correction by using a second thrust coefficient correction coefficient and a second power coefficient correction coefficient according to a mathematical relationship between the thrust coefficient and the power coefficient.

19. A wind tunnel test data correction system for a scaled test piece of a counter-rotating propeller according to claim 14 or 18, characterized in that: The total correction unit also uses the first pull coefficient correction coefficient and the first power coefficient correction coefficient to obtain the first full-size counter-rotating propeller propeller propulsion efficiency according to the first pull coefficient and the first power coefficient when both the Reynolds number and the Mach number are not similar, and performs Reynolds number correction on the wind tunnel test data of the counter-rotating propeller scaled test piece to obtain the Reynolds number correction result; The result of Reynolds number correction of the total correction unit is used, and the second pull coefficient correction coefficient and the second power coefficient correction coefficient are used to obtain the second full-size counter-rotating propeller fan propulsion efficiency according to the second pull coefficient and the second power coefficient. The Mach number correction is performed on the wind tunnel test data of the counter-rotating propeller fan scale test piece to obtain the result of Mach number correction, that is, the corrected propulsion efficiency of the full-size counter-rotating propeller fan under real wind tunnel conditions is obtained.

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