A method for calculating a performance parameter correction coefficient of an aero-engine

Abstract

The application discloses an aero-engine performance parameter correction coefficient calculation method, which comprises the following steps: changing the environment temperature to obtain the first rotating speed and the first performance parameter of the engine under different typical working states; fitting the relationship curve of the first rotating speed and the first performance parameter; calculating the corresponding second rotating speed under each typical conversion working state; combining the fitting curve and the temperature conversion coefficient to calculate the second performance parameter and the conversion performance parameter of the engine under the typical conversion working state; calculating the cumulative error of the second performance parameter and the conversion performance parameter under the typical conversion working state according to the temperature conversion coefficient; obtaining multiple cumulative errors by using different temperature conversion coefficients; and taking the temperature conversion coefficient corresponding to the minimum value of the multiple cumulative errors as the correction coefficient of the performance parameter. The application eliminates the influence of different environment temperatures on the correction of the performance parameter of the engine, and guarantees the accuracy of the performance evaluation and acceptance of the engine.

Description

Technical Field

[0001] This invention relates to the field of aero-engine testing technology, and specifically to a method for calculating correction coefficients for aero-engine performance parameters. Background Technology

[0002] Due to the characteristics of aero gas turbine shaft engines, for the same engine speed, an increase in atmospheric temperature will cause a decrease in the compressor's equivalent speed, resulting in a reduction in the compressor's pressure ratio and airflow. This leads to a decrease in engine output power and an increase in fuel consumption. Therefore, when an engine is tested under different atmospheric temperature conditions, the power, fuel consumption, and turbine inlet temperature at the same engine speed will vary significantly and cannot be used as a basis for engine performance evaluation and acceptance.

[0003] To evaluate or accept the performance of aero gas turbine shaft engines, the traditional method is to refer to gas turbine jet engines or turbofan engines, apply similarity theory, and convert the power, fuel consumption rate, and turbine inlet temperature of the turbine shaft engine measured under different atmospheric temperature conditions into the power, fuel consumption rate, and turbine inlet temperature under the standard atmospheric conditions of sea level when stationary. Then, the performance of the engine is evaluated and accepted based on the performance conversion parameters.

[0004] In practical operation, aero gas turbine shaft engines generally operate under a constant free turbine physical speed regulation. However, the fact that the flight Mach number and the converted speed of the gas generator rotor are constant does not guarantee the similarity of the power turbine's operating state, and therefore cannot guarantee the similarity of the entire engine's operating state. Furthermore, since the specific heat values ​​of air and gas vary with atmospheric temperature, the premise of a constant specific heat ratio—upon which the similarity principle rests—is not valid when the atmospheric temperature deviates from the standard value. In such cases, using traditional correction formulas for turbine inlet temperature correction will result in significant errors. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the use of traditional correction formulas to correct power, fuel consumption rate and turbine inlet temperature in the prior art will produce large errors, thereby providing a method for calculating the correction coefficient of aero-engine performance parameters that can reduce the error of the correction coefficient.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A method for determining correction coefficients for aero-engine performance parameters includes the following steps:

[0008] By changing the ambient temperature, the first engine speed and first performance parameters under typical operating conditions can be obtained;

[0009] Based on the first speed and the first performance parameter under the typical working conditions, a relationship curve between the first speed and the first performance parameter under the typical working conditions is plotted, and the relationship curve is fitted according to the fitting formula to obtain a fitted curve.

[0010] Calculate the second speed of the engine under typical equivalent operating conditions at different ambient temperatures, and calculate the second performance parameter under the typical equivalent operating conditions based on the second speed and the fitting curve.

[0011] Based on the second performance parameter, calculate the conversion performance parameter under the typical conversion working state;

[0012] By taking different values ​​of temperature conversion coefficients, and combining the second performance parameter and the conversion performance parameter, the cumulative error of the second performance parameter and the conversion performance parameter corresponding to each temperature heat transfer coefficient is calculated;

[0013] The temperature conversion factor corresponding to the calculated minimum cumulative error is used as the correction factor for the engine performance parameters.

[0014] According to some embodiments of the present invention, the fitting formula may be a quadratic polynomial, a cubic polynomial, a quartic polynomial, or a quintic polynomial.

[0015] According to some embodiments of the present invention, the fitting formula is as follows:

[0016] C = A + B1 × N + B2 × N 2 +B3×N 3

[0017] In the formula, C is the first performance parameter, A, B1, B2 and B3 are correction coefficients obtained through experimental statistics, and N is the first rotational speed.

[0018] According to some embodiments of the present invention, when the first performance parameter is obtained, the working dwell time of the engine under the typical operating condition is between 2 minutes and 10 minutes.

[0019] According to some embodiments of the present invention, the typical operating states include 50% maximum continuous state, 75% maximum continuous state, maximum continuous state, takeoff state, and continuous emergency state.

[0020] According to some embodiments of the present invention, the typical equivalent operating condition of the engine is 85%-100% takeoff condition.

[0021] According to some embodiments of the present invention, the second rotational speed is calculated under different ambient temperatures, and the calculation formula is as follows:

[0022]

[0023] In the formula, T1 is the ambient temperature, and N c N1 represents the rotational speed corresponding to the typical converted operating conditions at sea level and atmospheric pressure of 15°C, while N2 represents the second rotational speed under the typical converted operating conditions at different ambient temperatures.

[0024] According to some embodiments of the present invention, before calculating the converted performance parameters, the engine ambient pressure P0 is obtained, and the calculation formula is as follows:

[0025]

[0026] In the formula, C c C1 is the second performance parameter obtained by combining the second rotational speed with the fitted curve, and Y is the calculated performance parameter. T P0 is the temperature conversion factor, and P0 is the engine ambient pressure.

[0027] According to some embodiments of the present invention, the cumulative error between the second performance parameter and the converted performance parameter is calculated using the following formula:

[0028]

[0029] In the formula, K represents the cumulative error, m represents the number of selected ambient temperatures, n represents the number of selected typical engine conversion states, and C... c C1 is the second performance parameter obtained by combining the second rotational speed with the fitted curve.

[0030] According to some embodiments of the present invention, the engine performance parameters include turbine inlet temperature, engine power, and engine fuel consumption rate.

[0031] The technical solution of this invention has the following advantages:

[0032] The present invention provides a method for calculating correction coefficients for aero-engine performance parameters. This method involves changing the ambient temperature to obtain the engine's first rotational speed and first performance parameters under different typical operating conditions. A fitting formula is used to fit the relationship curve between the first rotational speed and the first performance parameter to obtain a fitted curve. The second rotational speed corresponding to each typical converted operating condition under different ambient temperatures is calculated. Combining the fitted curve and the temperature conversion coefficient, the second performance parameter and the converted performance parameter of the engine under the typical converted operating condition are calculated. Based on the temperature conversion coefficient, the cumulative error of the second performance parameter and the converted performance parameter under the typical converted operating condition is calculated. By using different temperature conversion coefficients, multiple cumulative errors are obtained, and the temperature conversion coefficient corresponding to the minimum value of these cumulative errors is taken as the correction coefficient for the engine performance parameters. The aero-engine performance parameter correction coefficient proposed in this invention eliminates the influence of different ambient temperatures on the correction of engine performance parameters. This allows for accurate evaluation of aero-engine performance parameters based on the corrected parameters, ensuring the accuracy of engine performance assessment and acceptance. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is the curve showing the relationship between the first rotational speed N and the first fuel consumption of the engine, as provided in Embodiment 1 of the present invention.

[0035] Figure 2 The curve showing the relationship between the first engine speed N and the first fuel consumption rate of the engine at 0°C intake temperature, and its fitting curve, provided in Embodiment 1 of the present invention.

[0036] Figure 3 The temperature conversion factor γ for different fuel consumption rates provided in Embodiment 1 of the present invention T The corresponding cumulative error μ in fuel consumption rate;

[0037] Figure 4 This is a graph showing the relationship between fuel consumption rate and converted power under different ambient temperatures under the traditional correction factor.

[0038] Figure 5 This is a graph showing the relationship between fuel consumption rate and converted power under different ambient temperatures under the correction coefficient obtained in Example 1 of the present invention.

[0039] Figure 6 This is a graph showing the relationship between turbine inlet temperature and converted power under different ambient temperatures under the traditional correction factor.

[0040] Figure 7 This is a graph showing the relationship between turbine inlet temperature and converted power under different ambient temperatures with the correction coefficient obtained in Embodiment 2 of the present invention.

[0041] Figure 8 This is a graph showing the relationship between power and converted speed under different ambient temperatures under the traditional correction factor;

[0042] Figure 9 This is a graph showing the relationship between power and converted speed under different ambient temperatures under the correction coefficient obtained in Embodiment 3 of the present invention. Detailed Implementation

[0043] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] Example 1:

[0048] In Embodiment 1 of the present invention, the specific steps for obtaining the correction coefficient for engine fuel consumption rate are as follows:

[0049] The engine is subjected to a performance calibration test. An engine that meets the performance requirements is selected and installed on a test bench. In some embodiments of the present invention, a high-altitude simulation test bench with dry air is selected as the test bench. The engine output torque is calibrated based on the torque measured on the test bench.

[0050] Specifically, the engine is a turboshaft engine, suitable for installation on helicopters. Before extracting engine performance parameters, it is necessary to shut down the helicopter's cockpit bleed air and helicopter electrical power extraction to improve the accuracy of the test.

[0051] To minimize errors, the engine ambient pressure is selected as the atmospheric pressure at sea level. Specifically, in Example 1, the engine ambient pressure P0 is 101.325 kPa. An ambient temperature T1 covering the engine's operating envelope is selected, ranging from -50°C to 55°C, with a temperature step of 1°C to 15°C. In Example 1, the ambient temperature T1 is set to 0°C, 15°C, 25°C, 35°C, and 50°C. Specifically, multiple temperature sensors are installed at the engine inlet. In Example 1, ten temperature sensors are used. The average value of the temperature parameters measured by the multiple sensors is taken as the ambient temperature T1.

[0052] Under each ambient temperature condition, the engine remains in each typical operating state for 2 to 10 minutes. In this embodiment 1, the engine remains in each typical operating state for more than five minutes. Typical operating states include: 50% maximum continuous state, 75% maximum continuous state, maximum continuous state, takeoff state, and continuous emergency state.

[0053] At each ambient temperature T1, the engine's first speed N and equivalent power P under each typical operating condition are... c And the first fuel consumption rate SFC1 and the first fuel consumption W f Record the data, and based on the recorded test data, obtain the first engine speed N and engine fuel consumption W at each ambient temperature. f Relationship curves, such as Figure 1 As shown.

[0054] Based on the correction coefficients obtained from experimental statistics, a fitting formula is derived. The fitting formula can be a quadratic, cubic, quartic, or quintic polynomial. In this embodiment 1, the fitting formula is:

[0055] W f =A + B1×N + B2×N 2 +B3×N 3

[0056] In the formula, W fThe engine fuel consumption is represented by A, B1, B2, and B3, which are correction coefficients obtained through experimental statistics, and N is the rotational speed of the engine gas generator. In this embodiment 1, taking 0°C as an example, the rotational speed N and engine fuel consumption W are related. f According to the fitted curve as follows Figure 2 As shown. The fitting methods for 15℃, 25℃, 35℃, and 50℃ are the same as those for 0℃, and will not be listed here.

[0057] After obtaining the fitted curve, it is necessary to calculate the second engine speed under typical converted operating conditions. Then, combined with the fitted curve, the second fuel consumption under typical converted operating conditions is obtained. Specifically, in this embodiment 1, the typical converted operating condition is 85%-100% takeoff condition, wherein the interval between typical converted operating conditions of the engine should be between 1%-5% takeoff condition. Specifically, multiple typical converted operating conditions can be selected. According to the formula for calculating the second engine speed under typical converted operating conditions, the second engine speed under different ambient temperatures is calculated. The calculation formula is as follows:

[0058]

[0059] In the formula, T1 is the ambient temperature, and N c The rotational speed is the typical converted operating state corresponding to atmospheric pressure at sea level of 15℃, and N1 is the second rotational speed under the typical converted operating state at different ambient temperatures. In this embodiment 1, the ambient temperature T1 is taken as 0℃, 15℃, 25℃, 35℃, and 50℃, respectively.

[0060] It is understood that in this embodiment 1, the typical equivalent operating states of the engine include: 92% takeoff state, 95% takeoff state, 98% takeoff state, and 100% takeoff state, that is, the engine speed N corresponding to the typical equivalent operating states at sea level atmospheric pressure of 15°C. c The values ​​are 0.92, 0.95, 0.98, and 1.0.

[0061] Table 1 shows the equivalent rotational speed N1 of the second engine at different ambient temperatures and the engine's typical operating condition at 15°C sea level atmospheric pressure. c Correspondence table:

[0062]

[0063] Substituting the calculated second engine speed N1 into the fitted curve, the second fuel consumption W of the engine under typical converted operating conditions at different ambient temperatures is calculated. f1 ;

[0064] It is understood that in this embodiment 1, the temperature conversion factor Y T γ is the temperature conversion factor for fuel consumption rate. TChoose different fuel consumption rate temperature conversion factors γ T According to the formula for calculating fuel flow rate:

[0065]

[0066] Calculate the equivalent fuel flow rate W under typical equivalent operating conditions of the engine. fc ; where the temperature conversion factor for fuel consumption rate is γ T The value ranges from 0.1 to 0.9, with a step size of 0.01.

[0067] Combined with the engine's converted power P c According to the conversion formula:

[0068] SFC2=W fc / P c

[0069] Calculate the second fuel consumption rate of the engine under typical converted operating conditions at different ambient temperatures;

[0070] It is understood that in this Example 1, the cumulative error K is the cumulative error μ of the engine fuel consumption rate, calculated according to the formula:

[0071]

[0072] Calculate the temperature conversion factor γ for different fuel consumption rates. T The cumulative error of engine fuel consumption rate under the given conditions, where m is the number of ambient temperatures T1, and n is the typical converted operating state N of the engine. c In Example 1, the number of values ​​is m = 5 and n = 4. The cumulative error μ of the engine fuel consumption rate can be calculated using variance or standard deviation.

[0073] Calculate the temperature conversion factor γ for different fuel consumption rates. T After calculating the cumulative error μ of the engine fuel consumption rate, select the fuel consumption rate temperature conversion factor γ corresponding to the minimum value of the cumulative error. T This serves as the temperature correction factor for the fuel consumption rate of the aero-engine.

[0074] Reference Figure 3 As shown in the figure, the temperature conversion factor γ corresponds to the vertex of the parabola. T The value is the fuel consumption rate correction coefficient determined by this method.

[0075] Reference Figure 4 and Figure 5 As shown, Figure 4 The fuel consumption rate and engine power P calculated using the traditional correction factor of 0.5 are... c Relationship diagram Figure 5The fuel consumption rate and engine power P calculated using the fuel consumption rate temperature conversion factor determined in Example 1 are... c Relationship diagram; based on Figure 4 and Figure 5 In comparison, Figure 4 The high dispersion of the curves indicates that the engine's fuel consumption rate varies significantly under different ambient temperatures. Figure 5 The low dispersion of each curve indicates that the correction coefficient obtained in Example 1 has eliminated the influence of different ambient temperatures on the engine fuel consumption correction coefficient, thus ensuring the accurate evaluation of the performance parameters of the aero-engine and guaranteeing the accuracy of engine performance assessment and acceptance.

[0076] Example 2:

[0077] In Embodiment 2 of the present invention, the specific steps for obtaining the correction coefficient for the engine power turbine inlet temperature are as follows:

[0078] The engine is subjected to a performance calibration test. An engine that meets the performance requirements is selected and installed on a test bench. In some embodiments of the present invention, a high-altitude simulation test bench with dry air is selected as the test bench. The engine output torque is calibrated based on the torque measured on the test bench.

[0079] Specifically, the engine is a turboshaft engine, suitable for installation on helicopters. Before extracting engine performance data, it is necessary to shut down the helicopter's cockpit bleed air and helicopter electrical power extraction to improve the accuracy of the test.

[0080] To minimize errors, the engine ambient pressure is selected as the atmospheric pressure at sea level. Specifically, in this embodiment 2, the engine ambient pressure P0 is 101.325 kPa. An ambient temperature T1 covering the engine's operating envelope is selected, with a range of -50°C to 55°C and a temperature step of 1°C to 15°C. In this embodiment 2, the ambient temperature T1 is set to 0°C, 15°C, 25°C, 35°C, and 50°C. Specifically, multiple temperature sensors are installed at the engine inlet. In this embodiment 2, ten temperature sensors are used, and the average value of the parameters measured by the multiple sensors is taken as the ambient temperature T1.

[0081] Under each typical temperature condition, the engine remains in each typical state for 2 to 10 minutes. In this embodiment 2, the engine remains in each typical operating state for more than five minutes. Typical operating states include: 50% maximum continuous state, 75% maximum continuous state, maximum continuous state, takeoff state, and continuous emergency state.

[0082] At each ambient temperature T1, the first engine speed N and the first turbine inlet temperature T under each typical operating condition are...45 Record the data, and based on the recorded experimental data, obtain the first rotational speed N and the first turbine inlet temperature T at each ambient temperature. 45 The relationship curve.

[0083] Based on the correction coefficients obtained from experimental statistics, a fitting formula is derived. This fitting formula can be a quadratic, cubic, quartic, or quintic polynomial. In this embodiment 2, the fitting formula is:

[0084] T 45 =A + B1×N + B2×N 2 +B3×N 3

[0085] In the formula, T 45 The first turbine inlet temperature is denoted as , A, B1, B2, and B3 are correction coefficients obtained through experimental statistics, and N is the first rotational speed.

[0086] After obtaining the fitted curve, it is necessary to calculate the second rotational speed under typical equivalent operating conditions, and then combine the fitted curve to obtain the second turbine inlet temperature under typical equivalent operating conditions.

[0087] Specifically, in this embodiment 2, the typical equivalent operating state is 85%-100% takeoff state, wherein the typical equivalent operating state interval of the engine should be between 1%-5% takeoff state. Specifically, multiple typical equivalent operating states can be selected. Based on the second speed calculation formula under typical equivalent operating conditions, the second speed under different ambient temperatures is calculated. The calculation formula is as follows:

[0088]

[0089] In the formula, T1 is the ambient temperature, and N c The rotational speed is the typical converted operating state corresponding to atmospheric pressure at sea level of 15℃, and N1 is the second rotational speed under the typical converted operating state at different ambient temperatures. In this embodiment 2, the ambient temperature T1 is taken as 0℃, 15℃, 25℃, 35℃, and 50℃, respectively.

[0090] It is understood that in this embodiment 2, the typical equivalent operating states of the engine include: 92% takeoff state, 95% takeoff state, 98% takeoff state, and 100% takeoff state, that is, the engine speed N corresponding to the typical equivalent operating states at sea level atmospheric pressure of 15°C. c The values ​​are 0.92, 0.95, 0.98, and 1.0.

[0091] Table 1 shows the equivalent rotational speed N1 of the second engine at different ambient temperatures and the engine's typical operating condition at 15°C sea level atmospheric pressure. c Correspondence table:

[0092]

[0093] Substituting the calculated second rotational speed N1 into the fitted curve, the second turbine inlet temperature T corresponding to the engine's typical equivalent operating condition under different ambient temperatures is calculated. 451 ;

[0094] It is understandable that in this embodiment 2, the temperature conversion factor Y T Turbocharger inlet temperature T 45 Temperature conversion factor β T Select different turbine inlet temperatures T 45 Temperature conversion factor β T According to the formula for calculating the turbine inlet temperature:

[0095]

[0096] Calculate the equivalent turbine inlet temperature T under typical equivalent operating conditions of the engine. 45c Among them, the turbine inlet temperature T 45 Temperature conversion factor β T The value ranges from 0.1 to 1.9, with a step size of 0.01.

[0097] It is understood that in this embodiment 2, the cumulative error K is the cumulative error ε of the engine turbine inlet temperature, calculated according to the cumulative error formula:

[0098]

[0099] Calculate different turbine inlet temperatures T 45 Temperature conversion factor β T The cumulative error of the engine's turbine inlet temperature under the given conditions, where m is the number of ambient temperatures T1, and n is the engine's typical converted operating condition N. c In Example 1, the number of elements is m = 5 and n = 4. The cumulative error ε of the engine turbine inlet temperature can be calculated using variance or standard deviation.

[0100] Calculate different turbine inlet temperatures T 45 Temperature conversion factor β T After calculating the cumulative error ε of the engine turbine inlet temperature, the turbine inlet temperature T corresponding to the minimum value of the cumulative error is selected. 45 Temperature conversion factor β T This serves as a correction factor for the turbine inlet temperature of the aero-engine.

[0101] Reference Figure 6 and Figure 7 As shown, Figure 6 The turbine inlet temperature and engine power P calculated using a traditional correction factor of 0.5 are...c Relationship diagram Figure 7 To use the turbine inlet temperature T determined in Example 2 of this embodiment 45 Temperature conversion factor β T The calculated turbine inlet temperature and the engine's equivalent power P c Relationship diagram; based on Figure 6 and Figure 7 In comparison, Figure 6 The high dispersion of the curves indicates that the experimental values ​​of the engine's turbine inlet temperature have significant errors under different ambient temperatures. Figure 5 The low dispersion of each curve indicates that the correction coefficient obtained in Example 2 eliminates the influence of different ambient temperatures on the engine turbine inlet temperature correction coefficient, which can accurately evaluate the performance parameters of the aero-engine and ensure the accuracy of engine performance evaluation and acceptance.

[0102] Example 3:

[0103] In Embodiment 3 of the present invention, the specific steps for obtaining the correction coefficient for engine output power are as follows:

[0104] The engine is subjected to a performance calibration test. An engine that meets the performance requirements is selected and installed on a test bench. In some embodiments of the present invention, a high-altitude simulation test bench with dry air is selected as the test bench. The engine output torque is calibrated based on the torque measured on the test bench.

[0105] Specifically, the engine is a turboshaft engine, suitable for installation on helicopters. Before extracting engine performance data, it is necessary to shut down the helicopter's cockpit bleed air and helicopter electrical power extraction to improve the accuracy of the test.

[0106] To minimize errors, the engine ambient pressure is selected as the atmospheric pressure at sea level. Specifically, in this embodiment 3, the engine ambient pressure P0 is 101.325 kPa. An ambient temperature T1 covering the engine's operating envelope is selected, with a range of -50°C to 55°C and a temperature step of 1°C to 15°C. In this embodiment 3, the ambient temperature T1 is set to 0°C, 15°C, 25°C, 35°C, and 50°C. Specifically, multiple temperature sensors are installed at the engine inlet. In this embodiment 3, ten temperature sensors are used, and the average value of the parameters measured by the multiple sensors is taken as the ambient temperature T1.

[0107] Under each typical temperature condition, the engine remains in each typical state for 2 to 10 minutes. In this embodiment 3, the engine remains in each typical operating state for more than five minutes. Typical operating states include: 50% maximum continuous state, 75% maximum continuous state, maximum continuous state, takeoff state, and continuous emergency state.

[0108] At each ambient temperature T1, the first engine speed N and first output power P under each typical operating condition were recorded. Based on the recorded experimental data, the relationship curve between the first engine speed N and the first output power P at each ambient temperature was obtained.

[0109] Based on the correction coefficients obtained from experimental statistics, a fitting formula is derived. The fitting formula can be a quadratic, cubic, quartic, or quintic polynomial. In this embodiment 3, the fitting formula is:

[0110] P = A + B1 × N + B2 × N 2 +B3×N 3

[0111] In the formula, P is the first output power, A, B1, B2 and B3 are correction coefficients obtained through experimental statistics, and N is the first rotational speed.

[0112] After obtaining the fitted curve, it is necessary to calculate the second rotational speed under typical converted operating conditions, and then combine it with the fitted curve to obtain the second output power under typical converted operating conditions.

[0113] Specifically, in this embodiment 3, the typical equivalent operating state is 85%-100% takeoff state, wherein the typical equivalent operating state interval of the engine should be between 1%-5% takeoff state. Specifically, multiple typical equivalent operating states can be selected. Based on the second speed calculation formula under typical equivalent operating conditions, the second speed under different ambient temperatures is calculated. The calculation formula is as follows:

[0114]

[0115] In the formula, T1 is the ambient temperature, and N c The rotational speed is the typical converted operating state corresponding to atmospheric pressure at sea level of 15℃, and N1 is the second rotational speed under the typical converted operating state at different ambient temperatures. In this embodiment 2, the ambient temperature T1 is taken as 0℃, 15℃, 25℃, 35℃, and 50℃, respectively.

[0116] It is understood that in this embodiment 3, the typical equivalent operating states of the engine include: 92% takeoff state, 95% takeoff state, 98% takeoff state, and 100% takeoff state, that is, the engine speed N corresponding to the typical equivalent operating states at sea level atmospheric pressure of 15°C. c The values ​​are 0.92, 0.95, 0.98, and 1.0.

[0117] Table 1 shows the equivalent rotational speed N1 of the second engine at different ambient temperatures and the engine's typical operating condition at 15°C sea level atmospheric pressure. c Correspondence table:

[0118]

[0119] Substitute the calculated second speed N1 into the fitted curve to calculate the second output power P1 of the engine under typical converted working conditions at different ambient temperatures.

[0120] It is understood that in this embodiment 3, the temperature conversion factor Y T The power-temperature conversion factor α T Choose different power-temperature conversion factors α T According to the formula for calculating the turbine inlet temperature:

[0121]

[0122] Calculate the equivalent power P of the engine under typical equivalent operating conditions. c The power-temperature conversion factor α is used to calculate the power-temperature conversion factor. T The value ranges from 0.1 to 0.9, with a step size of 0.01.

[0123] It is understood that in this embodiment 3, the cumulative error K is the cumulative error τ of the engine output power, calculated according to the formula for cumulative error:

[0124]

[0125] Calculate the temperature conversion factor α for different power levels. T The cumulative error of engine output power under the following conditions, where m is the number of ambient temperatures T1, and n is the typical converted operating state N of the engine. c In Example 3, the number of elements is m=5 and n=4. The cumulative error ε of the engine output power can be calculated using variance or standard deviation.

[0126] Calculate the temperature conversion factor α for different power levels. T After calculating the cumulative error τ of the engine turbine inlet temperature, the power-temperature conversion factor α corresponding to the minimum value of the cumulative error is selected. T This serves as a correction factor for the output power of the aero-engine.

[0127] Reference Figure 8 and Figure 9 As shown, Figure 8 The output power calculated using the traditional correction factor of 0.5 is compared with the engine's converted power P. c Relationship diagram Figure 9 To use the power-temperature conversion factor α determined in Example 1 of this embodiment. T The calculated output power and the engine's equivalent power P c Relationship diagram; based on Figure 8 and Figure 9 In comparison, Figure 8 The high dispersion of the curves indicates that the experimental values ​​of the engine's output power have significant errors under different ambient temperatures. Figure 9 The low dispersion of each curve indicates that the correction coefficient obtained in Example 3 eliminates the influence of different ambient temperatures on the engine output power correction coefficient, which can accurately evaluate the performance parameters of the aero-engine and ensure the accuracy of engine performance evaluation and acceptance.

[0128] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for determining correction coefficients for performance parameters of an aero-engine, characterized in that, Includes the following steps: By changing the ambient temperature, the first engine speed and first performance parameters under typical operating conditions can be obtained; Based on the first speed and the first performance parameter under the typical working conditions, a relationship curve between the first speed and the first performance parameter under the typical working conditions is plotted, and the relationship curve is fitted according to the fitting formula to obtain a fitted curve. Calculate the second speed of the engine under typical equivalent operating conditions at different ambient temperatures, and calculate the second performance parameter under the typical equivalent operating conditions based on the second speed and the fitting curve. Based on the second performance parameter, calculate the conversion performance parameter under the typical conversion working state; By taking temperature conversion factors of different values, and combining the second performance parameter and the conversion performance parameter, the cumulative error of the second performance parameter and the conversion performance parameter corresponding to each temperature conversion factor is calculated; The temperature conversion factor corresponding to the calculated minimum cumulative error is used as the correction factor for the engine performance parameters.

2. The method for determining the correction coefficient of aero-engine performance parameters according to claim 1, characterized in that, The fitting formula is a quadratic polynomial, a cubic polynomial, a quartic polynomial, or a quintic polynomial.

3. The method for determining the correction coefficient of aero-engine performance parameters according to claim 2, characterized in that, The fitting formula is as follows: In the formula, The first performance parameter, , and These are correction coefficients obtained through experimental statistics. This refers to the first rotational speed.

4. The method for determining the correction coefficient of aero-engine performance parameters according to claim 1, characterized in that, When the first performance parameter is obtained, the engine's working dwell time under the typical operating conditions is between 2 minutes and 10 minutes.

5. The method for determining the correction coefficient of aero-engine performance parameters according to claim 4, characterized in that, The typical operating states include 50% maximum continuous state, 75% maximum continuous state, maximum continuous state, takeoff state, and continuous emergency state.

6. The method for determining the correction coefficient of aero-engine performance parameters according to claim 1, characterized in that, The engine's typical operating condition is 85%-100% during takeoff.

7. The method for determining the correction coefficient of aero-engine performance parameters according to claim 1, characterized in that, The second rotational speed is calculated under different ambient temperatures using the following formula: In the formula, For ambient temperature, The rotational speed corresponds to the typical converted operating conditions at sea level and atmospheric pressure of 15°C. The second rotational speed is given under the typical converted operating conditions at different ambient temperatures.

8. The method for determining the correction coefficient of aero-engine performance parameters according to claim 1, characterized in that, Before calculating the converted performance parameters, obtain the engine ambient pressure. The calculation formula is: In the formula, For the aforementioned conversion performance parameters, The second performance parameter is derived by combining the second rotational speed with the fitted curve. This is the temperature conversion factor. For engine environmental pressure.

9. The method for determining the correction coefficient of aero-engine performance parameters according to claim 1, characterized in that, The cumulative error between the second performance parameter and the converted performance parameter is calculated using the following formula: In the formula, The cumulative error is represented by m, which is the number of ambient temperatures selected, and n, which is the number of typical engine conversion states selected. To select the corresponding number of the conversion performance parameters, The second performance parameter is obtained by selecting a corresponding number of the second rotational speeds and combining them with the fitted curve.

10. The method for determining the correction coefficient of aero-engine performance parameters according to any one of claims 1 to 9, characterized in that, The engine performance parameters include turbine inlet temperature, engine power, and engine fuel consumption rate.

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