Precooling heat exchanger flow resistance equivalent simulation method based on cylindrical double-pore plate adjustment

Abstract

The invention discloses a pre-cooling heat exchanger flow resistance equivalent simulation method based on cylindrical double-pore plate adjustment. The method comprises the following steps: constructing a mathematical model of the influence of an incoming flow Reynolds number on a resistance coefficient and a total pressure loss coefficient of a microtube pre-cooling heat exchanger; according to the overall dimension and the flow resistance range of the micro-tube pre-cooling heat exchanger and the influence rule of the equivalent diameter ratio and the relative plate distance on the total pressure loss coefficient of the double-pore plate under different incoming flow Reynolds numbers, the geometric parameters of the double-pore plate are determined; and under the determined equivalent diameter ratio and relative plate spacing, according to the mathematical model of the influence of the incoming flow Reynolds number and the double-pore plate hole staggering coefficient on the total pressure loss coefficient, the flow resistance of the double-pore plate is kept equal to that of the precooling heat exchanger, the double-pore plate hole staggering coefficient under the corresponding incoming flow Reynolds number is obtained, and equivalent simulation of the flow resistance of the precooling heat exchanger is achieved. According to the invention, the technical problem that equal-proportion scale reduction cannot be carried out on the submillimeter microtube precooler in the existing pre-cooling type air inlet system scale reduction test is solved, and more economical and efficient pre-cooling type air inlet system test can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of flow resistance equivalent simulation of pre-cooling heat exchangers, and relates to the flow resistance characteristic modeling and equivalent simulation of microtube pre-cooling heat exchangers in the air intake system of wide-speed aircraft. Specifically, it relates to a flow resistance equivalent simulation method of a pre-cooling heat exchanger based on the adjustment of a cylindrical double orifice plate. Background Art

[0002] In the case of a wide-speed engine under a high Mach number incoming flow, the temperature of the incoming air rises sharply due to the intense compression effect. If not cooled in time, the high-temperature air will directly affect the working efficiency and stability of the engine. To meet the cooling requirements of the wide-speed engine for the high Mach number incoming flow, in the prior art, a microtube pre-cooling heat exchanger is usually arranged at the outlet of the air intake duct. By means of a microtube array, the heat exchange area is greatly increased, and the internal flow resistance is effectively reduced to achieve efficient cooling of the hot air.

[0003] However, the flow resistance characteristics under the flow-thermal coupling of the microtube pre-cooling heat exchanger have a great influence on the matching operation of the air intake duct and the engine. It is necessary to carry out air intake duct tests with a flow resistance unit with a pre-cooler to support the research on the matching working characteristics of the wide-speed pre-cooling air intake duct and the engine. In order to reduce the requirements for the nozzle size of the high Mach number wind tunnel test bench and greatly reduce the test cost, the air intake duct test is usually carried out in a scaled-down manner. Considering that the pre-cooling heat exchanger uses a thin-walled microtube array heat exchange unit, the pipe diameter is in the range of 0.5 - 2.5 mm, and the wall thickness is about 1 / 20 of the microtube diameter size, it is very difficult to scale down the pre-cooling heat exchanger proportionally.

[0004] In the existing scaled-down tests of pre-cooling air intake ducts, simplified models or alternative structures are usually used to simulate the flow resistance characteristics of the microtube pre-cooling heat exchanger. However, these methods are difficult to achieve accurate matching of the flow resistance under different working conditions, which affects the research on the matching working characteristics of the pre-cooling air intake duct and the engine. For example, some methods use a perforated plate or a honeycomb structure to simulate the flow resistance of the microtube array. However, since there are significant differences between the geometric shapes and flow resistance characteristics of these structures and the microtube array, it is difficult to achieve accurate flow resistance equivalent simulation at different incoming flow Reynolds numbers. There are also some methods that simulate the flow resistance of the microtube array by adjusting the geometric parameters of the orifice plate. However, since there is no clear mathematical relationship between the flow resistance characteristics of the orifice plate and the microtube array, it is difficult to achieve accurate matching of the flow resistance under different working conditions.

[0005] In summary, in scaled-down testing of precooled inlet ducts, micro-tube precooling heat exchangers are difficult to scale to full scale, and accurately measuring and simulating their flow resistance characteristics presents numerous technical challenges. Therefore, constructing a simple mechanism for equivalent simulation of the flow-thermal coupled flow resistance characteristics of precooling heat exchangers, building an equivalent simulation method for precooling heat exchangers based on the regulation of a cylindrical double-orifice plate, and scaling the cylindrical double-orifice plate to meet the scaled-down testing requirements for precooled inlet ducts with flow resistance units are pressing technical challenges in the field of precooled inlet testing. Summary of the Invention

[0006] (1) Purpose of the invention In view of the above-mentioned defects and shortcomings in the prior art, the main purpose of the present invention is to provide a method for equivalent simulation of the flow resistance of a pre-cooling heat exchanger based on adjustment of a cylindrical double-orifice plate. By constructing a mathematical model of the influence of the incoming flow Reynolds number on the resistance coefficient and the total pressure loss coefficient of the micro-tube pre-cooler, combined with the geometric parameter design of the cylindrical double-orifice plate and the dynamic adjustment mechanism of the staggered hole coefficient, the equivalent simulation of the flow resistance characteristics of the pre-cooling heat exchanger under different Reynolds numbers is achieved, so as to solve the problem in the prior art that the micro-tube pre-cooling heat exchanger in the pre-cooling inlet duct scale test cannot be scaled up in proportion, reduce the cost and difficulty of high Mach number wind tunnel tests, and meet the needs of research on the matching characteristics of the pre-cooling inlet duct and the engine in a wide speed range.

[0007] (2) Technical solution To achieve the above objectives, the present invention provides a method for simulating the flow resistance of a precooling heat exchanger based on adjustment of a cylindrical double-orifice plate. The method is used to simulate the flow resistance characteristics of a micro-tube precooling heat exchanger in a scaled-down precooling inlet duct test. The method comprises at least the following steps: S100. Constructing a mathematical model for the flow resistance characteristics of a micro-tube pre-cooling heat exchanger Based on the flow resistance characteristics of microtube arrays of microtube precoolers with typical structural dimensions under different operating conditions, a mathematical model was constructed to examine the influence of the incoming flow Reynolds number on the resistance coefficient and total pressure loss coefficient of the microtube precooler heat exchanger. S200. Determine the geometric parameters of a cylindrical double-hole plate Based on the outer dimensions and flow resistance range of the micro-tube pre-cooling heat exchanger, as well as the influence of the equivalent diameter ratio and relative plate spacing of the cylindrical double-hole plate on the total pressure loss coefficient of the double-hole plate under different incoming flow Reynolds numbers, the equivalent diameter ratio, relative plate spacing and related geometric parameters of the cylindrical double-hole plate are determined. S300. Equivalent simulation of flow resistance characteristics of a micro-tube pre-cooling heat exchanger Under the determined equivalent diameter ratio and relative plate spacing, according to the mathematical model of the influence of the incoming flow Reynolds number and the staggered hole coefficient of the double-hole plate on the total pressure loss coefficient of the double-hole plate, keep the flow resistance of the cylindrical double-hole plate equal to that of the microtube precooling heat exchanger, obtain the staggered hole coefficient of the double-hole plate under the corresponding incoming flow Reynolds number, and use the cylindrical double-hole plate to realize the equivalent simulation of the flow resistance of the microtube precooling heat exchanger.

[0008] (III) Technical Effects Compared with the existing technology, the method for equivalent simulation of the flow resistance of the precooling heat exchanger based on the adjustment of the cylindrical double-hole plate proposed by the present invention constructs a mathematical model of the influence of the incoming flow Reynolds number on the resistance coefficient and total pressure loss coefficient of the microtube precooling heat exchanger, and combines the cooperative adjustment mechanism of the equivalent diameter ratio, relative plate spacing and staggered hole coefficient of the cylindrical double-hole plate to realize the total pressure loss coefficient of the double-hole plate σ k to match the total pressure loss coefficient of the microtube array of the microtube precooler σ g in a wide Reynolds number range. While meeting the equivalent simulation of the flow resistance characteristics of the microtube precooling heat exchanger under different flight conditions of the precooling inlet, it is also convenient to perform proportional scaling of the cylindrical double-hole plate, realize the scaled test of the precooling inlet with a flow resistance unit, reduce the requirements for the nozzle size of the high Mach number wind tunnel test bench, and greatly reduce the test cost, supporting the research needs of the matching working characteristics of the wide-speed-range precooling inlet and the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Shows the flow chart of the method for equivalent simulation of the flow resistance of the precooling heat exchanger based on the adjustment of the cylindrical double-hole plate.

[0010] Figure 2 Shows the schematic diagram of the microtube array structure of the precooling heat exchanger, where: Figure (A) is the three-dimensional structure schematic diagram of the microtube precooling heat exchanger, and the enlarged view further shows the arrangement of the microtubes in the cylindrical structure and the detailed features at the ends of the microtubes. Figure (B) is the cross-sectional schematic diagram of the microtube array, describing the periodic arrangement structure of the microtubes, marking the transverse tube spacing S T and the longitudinal tube spacing S L , and shows the diameter of the microtube d g and its heat transfer interface.

[0011] Figure 3 Shows the equivalent schematic diagram of the cylindrical double-hole plate and the precooling heat exchanger, where: Figure (A) is the three-dimensional structure schematic diagram of the precooling heat exchanger, and the enlarged view further shows the arrangement of the microtubes in the structure and the flow path. Figure (B) is the three-dimensional structure schematic diagram of the cylindrical double-hole plate, and the enlarged view shows the flow path of the fluid through the staggered hole structure.

[0012] Figure 4 Shows a schematic diagram of a cylindrical double-orifice plate structure, where: (A) is a three-dimensional schematic diagram of the cylindrical double-orifice plate, and the following sectional detail diagram further shows the path of fluid passing through the double-orifice plate and the arrangement of orifice openings. (B) is a parametric schematic diagram of the cylindrical double-orifice plate, with its key geometric parameters marked in detail, including the equivalent diameter ratio β , the number of orifices N , the width of the orifice plate W , the diameter of the cylinder D 1 ,D 2 , the diameter of the orifice opening d k , the thickness of the orifice plate δ , the pitch diameter between orifices L , the number of rows α and the distance between plates t etc.

[0013] Figure 5 Shows a schematic diagram of the variation law of the total pressure loss coefficient of the cylindrical double-orifice plate under different incoming flow Reynolds numbers and staggered orifice coefficients. Specific implementation manner

[0014] The present invention aims to provide a method for equivalent simulation of the flow resistance of a precooling heat exchanger based on the adjustment of a cylindrical double-orifice plate, which is used to realize the equivalent simulation of the flow resistance characteristics of a microtube precooling heat exchanger in a scaled test of a precooling inlet. The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0015] As a specific example, as Figure 1 shown, the method for equivalent simulation of the flow resistance of a precooling heat exchanger based on the adjustment of a cylindrical double-orifice plate provided by the present invention specifically includes the following steps when implemented: S100. Construct a mathematical model of the flow resistance characteristics of the microtube precooling heat exchanger According to the flow resistance characteristics of the microtube array of the microtube precooler with typical structural dimensions under different working conditions, construct a mathematical model of the influence of the incoming flow Reynolds number on the resistance coefficient C f and the total pressure loss coefficient of the microtube precooling heat exchanger.

[0016] Preferably, the microtube precooler in step S100 is as Figure 2 shown, and its tube diameter Selected in the range of 0.5~2.5mm, the microtubes are arranged in a staggered pattern, and the typical structural dimensions are selected as the transverse tube pitch of the staggered tubes S T , longitudinal tube pitch S L . In the embodiment of the present invention, step S100 may specifically include the following sub-steps when implemented: S101. Calculate the incoming flow Reynolds number of the microtube pre-cooling heat exchanger microtube array according to the incoming flow temperature, density, and velocity of the microtube pre-cooling heat exchanger microtube array under different flight conditions of the pre-cooled inlet duct : Among them, is the density at the incoming flow temperature of the microtube array; μ m is the viscosity at the incoming flow temperature of the microtube array; u in is the incoming flow velocity of the microtube array; the outer diameter of the microtube is the characteristic length; in this embodiment, for flight Mach numbers 0~5 and flight altitudes 0~30km, the outer diameter of the microtube is taken , and the incoming flow Reynolds number is controlled by adjusting the flow rate of the microtube pre-cooling heat exchanger in the range of 3000~6000.

[0017] S102. Obtain the variation law of the resistance coefficient of the microtube pre-cooling heat exchanger microtube array under different transverse tube pitches, longitudinal tube pitches, and incoming flow Reynolds numbers through simulation analysis, and construct a mathematical model of the influence of the incoming flow Reynolds number of the microtube pre-cooling heat exchanger microtube array on the resistance coefficient: Among them, C f is the resistance coefficient of the microtube array under the corresponding tube pitch; The coefficient is determined by polynomial fitting based on the least squares method; in this embodiment, , the fitting correlation coefficient , close to 1, with a high confidence level.

[0018] S103. According to the variation law of the resistance coefficient and total pressure loss coefficient of the microtube pre-cooling heat exchanger microtube array under different incoming flow Reynolds numbers, construct a mathematical model of the influence of the incoming flow Reynolds number and resistance coefficient of the microtube pre-cooling heat exchanger microtube array on the total pressure loss coefficient: Among them, is the total pressure loss coefficient of the microtube array; n is the number of tube rows; b 1 、b2 The coefficient is determined by fitting a power function based on the least squares method; in this embodiment, the number of tube rows n is taken as 24, , , and the fitting correlation coefficient is close to 1, with a relatively high confidence level.

[0019] S104. According to the mathematical model constructed in sub-steps S102 and S103, calculate the total pressure loss coefficient of the microtube array of the microtube precooling heat exchanger at different incoming flow Reynolds numbers.

[0020] S200. Determine the geometric parameters of the cylindrical double-orifice plate Based on the outer contour dimensions of the microtube precooling heat exchanger, the range of flow resistance, and the influence law of the equivalent diameter ratio β , relative plate spacing of the cylindrical double-orifice plate on the total pressure loss coefficient , determine the equivalent diameter ratio, relative plate spacing, and related geometric parameters of the cylindrical double-orifice plate.

[0021] Preferably, the cylindrical double-orifice plate in step S200 is as Figure 3 shown, its outer cylinder outer diameter is close to the outer diameter of the microtube precooling heat exchanger, and the orifice plate width is consistent with the width of the microtube precooling heat exchanger. The calculation method of the equivalent diameter ratio of the cylindrical double-orifice plate is , where β is the equivalent diameter ratio of the double-orifice plate, A1 is the flow channel area, and A2 is the total area of the small holes in the outer orifice plate. In this embodiment β the value range is 0.22 - 0.52.

[0022] As [[ID=3,8]] Figure 4 shown, the calculation method of the relative plate spacing of the cylindrical double-orifice plate is , where is the relative plate spacing of the double-orifice plate, t is the double-orifice plate spacing; is the orifice plate thickness. In this embodiment β the value range is 0.5 - 1.1.

[0023] In the embodiment of the present invention, step S200 may specifically include the following sub-steps when implemented: S201. Based on the outer contour dimensions of the microtube precooling heat exchanger, when the relative plate spacing is 1, preliminarily determine the number of orifices N, orifice diameter d k , orifice plate thickness , outer cylinder outer diameter D1 of the orifice plate, inner cylinder outer diameter D2 of the orifice plate, and calculate the equivalent diameter ratio β of the cylindrical double-orifice plate; in this embodiment, the number of orifices N is taken as 495, and the orifice diameterd k The value range is 6 - 12 mm, and the orifice plate thickness is taken as 5 mm, the outer cylinder outer diameter D1 of the orifice plate is taken as 300 mm, and the inner cylinder outer diameter D2 of the orifice plate has a value range of 289 - 290 mm.

[0024] S202. According to the flow Reynolds numbers of the microtube pre - cooler microtube array under different flight conditions of the pre - cooled inlet passage determined by sub - step S101 in the size range, for the minimum Reynolds number of 3000, when the stagger - hole coefficient K is 0, the total pressure loss coefficient of the double - orifice plate under different equivalent diameter ratios β is obtained through simulation analysis variation law.

[0025] S203. According to the minimum value of 3.91% of the total pressure loss coefficient of the microtube pre - cooler microtube array under different flow Reynolds numbers determined by sub - step S104, and the total pressure loss coefficient of the double - orifice plate under different equivalent diameter ratios obtained in sub - step S202 β to determine the appropriate equivalent diameter ratio . .

[0026] S204. According to the flow Reynolds numbers of the microtube pre - cooler microtube array under different flight conditions of the pre - cooled inlet passage determined by sub - step S101 in the size range, for the maximum Reynolds number of 6000, when the stagger - hole coefficient K is 1, the total pressure loss coefficient of the double - orifice plate under different relative plate spacings is obtained through simulation analysis variation law.

[0027] S205. According to the maximum value of 20.79% of the total pressure loss coefficient of the microtube pre - cooler microtube array under different Reynolds numbers determined by sub - step S104, and the total pressure loss coefficient of the double - orifice plate under different relative plate spacings obtained in sub - step S204 to determine the appropriate relative plate spacing of the double - orifice plate . .

[0028] S206. According to the determined equivalent diameter ratio β and relative plate spacing , maintaining the number of orifices N, orifice plate thickness and outer cylinder outer diameter D1 initially determined in sub - step S201 unchanged, calculate and determine the orifice diameter d k of the cylindrical double - orifice plate, and the inner cylinder outer diameter D2 In this embodiment, the aperture of the cylindrical double-hole plate is , outer diameter of the inner tube of the orifice plate .

[0029] S300. Equivalent simulation of flow resistance characteristics of a micro-tube pre-cooling heat exchanger

[0030] Under the determined equivalent diameter ratio and relative plate spacing, according to the incoming flow Reynolds number and the double-hole plate staggered hole coefficient K A mathematical model for the influence of the total pressure loss coefficient of the double-orifice plate is developed. The flow resistance of the cylindrical double-orifice plate and the micro-tube pre-cooling heat exchanger is kept equal. The staggered hole coefficient of the double-orifice plate under the corresponding incoming flow Reynolds number is obtained, and the equivalent simulation of the flow resistance of the micro-tube pre-cooling heat exchanger is realized using the cylindrical double-orifice plate.

[0031] As a preferred method, the staggered hole coefficient of the cylindrical double-hole plate in step S300 is calculated as follows: , where K is the staggered hole coefficient of the double-hole plate, θ is the centerline angle of the inner and outer orifice plate strings, α is the angle between the center lines of two adjacent holes in the outer orifice plate. In this embodiment, the value range of K is 0~1. In the embodiment of the present invention, step S300 may specifically include the following sub-steps when implemented: S301. The double-hole plate geometric parameters determined in step S200, including the hole plate width W k , outer diameter of outer tube D1, inner diameter of inner tube D2, number of openings N, aperture d k , orifice plate thickness et al., obtain different incoming flow Reynolds numbers through simulation analysis The effect of the staggered hole coefficient K of the lower double-hole plate on the total pressure loss coefficient The influence of the law (such as Figure 5 As shown), construct the incoming flow Reynolds number , Double hole plate staggered hole coefficient K to total pressure loss coefficient Mathematical model of impact: in, The coefficients are determined by power function fitting based on the least squares method; in this embodiment, , fitting correlation coefficient , is close to 1, and the confidence level is high.

[0032] S302. Determine the incoming flow Reynolds number under the target operating conditions :For the specific flight conditions and flow rate of the pre-cooling inlet, the incoming flow Reynolds number is determined in sub-step S101 .

[0033] S303. Calculate the resistance coefficient of the microtube precooling heat exchanger: According to the typical structural dimensions of the microtube precooling heat exchanger, determine the resistance coefficient of the microtube array of the microtube precooling heat exchanger from the mathematical model in sub-step S102 .

[0034] S304. Calculate the total pressure loss coefficient of the microtube precooling heat exchanger: Then determine the total pressure loss coefficient of the microtube array of the microtube precooling heat exchanger from the mathematical model in sub-step S103 .

[0035] S305. Calculate and match the misalignment coefficient K of the double orifice plate: Keep the total pressure loss coefficient of the double orifice plate equal to the total pressure loss coefficient of the microtube array of the microtube precooling heat exchanger . Determine that the misalignment coefficient K of the double orifice plate is 0.581 from the mathematical model in sub-step S301, and realize the equivalent simulation of the flow resistance of the precooling heat exchanger

[0036] In summary, the present invention effectively realizes the high-precision simulation of the flow resistance characteristics of the microtube precooling heat exchanger by constructing a flow resistance mathematical model of the microtube precooling heat exchanger and combining with the equivalent adjustment mechanism of the cylindrical double orifice plate. This method not only overcomes the technical problem that it is difficult to scale the microtube array proportionally in the scaled experiment, but also significantly reduces the requirements for experimental equipment and test costs, and improves the engineering applicability of the wide-speed-range precooling intake system. The method of the present invention can be widely applied to the optimization of the precooling inlet of wide-speed-range engines, the wind tunnel test of precooling inlets, and the research of hypersonic aircraft, and has important engineering value and application prospects

[0037] Through the above embodiments, the purpose of the present invention is completely and effectively realized. Those skilled in the art can understand that the present invention includes but is not limited to the content described in the drawings and the above specific embodiments. Although the present invention has been described with respect to the currently considered most practical and preferred embodiments, it should be understood that the present invention is not limited to the disclosed embodiments, and any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims

Claims

1. A flow resistance equivalent simulation method for a precooling heat exchanger based on the adjustment of a cylindrical double-hole plate, characterized in that The method at least includes the following steps when implemented: S100. Based on the flow resistance characteristics of the microtube array of the microtube pre-cooler with typical structural dimensions under different working conditions, construct a mathematical model of the influence of the incoming flow Reynolds number on the resistance coefficient and total pressure loss coefficient of the microtube pre-cooling heat exchanger; S200. According to the outer contour dimensions of the microtube pre-cooling heat exchanger, the range of flow resistance, and the influence law of the equivalent diameter ratio and relative plate spacing of the cylindrical double-hole plate on the total pressure loss coefficient of the double-hole plate under different incoming flow Reynolds numbers, determine the equivalent diameter ratio, relative plate spacing and related geometric parameters of the cylindrical double-hole plate; S300. Under the determined equivalent diameter ratio and relative plate spacing of the double-hole plate, based on the mathematical model of the influence of the incoming flow Reynolds number and the staggered hole coefficient of the double-hole plate on the total pressure loss coefficient of the double-hole plate, keep the flow resistance of the cylindrical double-hole plate equal to that of the microtube pre-cooling heat exchanger, obtain the staggered hole coefficient of the double-hole plate corresponding to the incoming flow Reynolds number, and use the cylindrical double-hole plate to realize the equivalent simulation of the flow resistance of the microtube pre-cooling heat exchanger.

2. A flow resistance equivalent simulation method of a precooling heat exchanger based on the adjustment of a cylindrical double-hole plate according to claim 1, characterized in that, In the above step S100, the diameter of the microtube pre-cooling heat exchanger is selected within the range of 0.5 to 2.5 mm. The microtubes are arranged in a staggered pattern, and the typical structural dimensions are selected as the transverse tube pitch S T , the longitudinal tube pitch S L .

3. A flow resistance equivalent simulation method of a precooling heat exchanger based on the adjustment of a cylindrical double-hole plate according to claim 1, characterized in that In the above step S200, the determined geometric parameters related to the cylindrical double-hole plate at least include the width of the orifice plate W k , the outer diameter of the outer cylinder D 1. The outer diameter of the inner cylinder D 2. The number of openings N , the diameter of the opening d k , the thickness of the orifice plate .

4. A flow resistance equivalent simulation method of a precooling heat exchanger based on the adjustment of a cylindrical double-hole plate according to claim 3, characterized in that, In the above step S200, the outer diameter of the outer cylinder of the cylindrical double-hole plate is close to the outer diameter of the microtube pre-cooling heat exchanger, and the width of the orifice plate is the same as the width of the microtube pre-cooling heat exchanger.

5. A flow resistance equivalent simulation method for a precooling heat exchanger based on the adjustment of a cylindrical double-orifice plate according to claim 3, characterized in that, In the above step S200, the calculation method of the equivalent diameter ratio of the cylindrical double-hole plate is , β where is the equivalent diameter ratio of the double-hole plate, A1 is the flow channel area, and A2 is the total area of the small holes in the outer orifice plate.

6. A flow resistance equivalent simulation method of a precooling heat exchanger based on the adjustment of a cylindrical double orifice plate according to claim 3, characterized in that, In the above step S200, the calculation method of the relative plate spacing of the cylindrical double-hole plate is , where is the relative plate spacing of the double-hole plate, and t is the double-hole plate spacing; is the thickness of the orifice plate.

7. A flow resistance equivalent simulation method for a precooling heat exchanger based on the adjustment of a cylindrical double orifice plate according to claim 1, characterized in that In the above step S300, the calculation method of the misalignment coefficient of the cylindrical double-hole plate is , where Κ is the misalignment coefficient of the double-hole plate, θ is the central line angle of the inner and outer hole plates with overlapping holes, α is the central line angle between two adjacent holes in the circumferential direction of the outer hole plate.

8. A flow resistance equivalent simulation method for a precooling heat exchanger based on the adjustment of a cylindrical double-orifice plate according to claim 1, characterized in that, Step S100 at least includes the following sub-steps when implemented: S101. Calculate the incoming flow Reynolds number of the microtube array of the microtube pre-cooling heat exchanger according to the incoming flow temperature, density, and velocity of the microtube array of the pre-cooling inlet duct under different flight conditions : Among them, is the density at the inlet flow temperature of the microtube array; μ m is the viscosity at the inlet flow temperature of the microtube array; u in is the inlet flow velocity of the microtube array; the outer diameter of the microtube is the characteristic length; S102. Obtain the change law of the resistance coefficient of the microtube array of the microtube pre-cooling heat exchanger under different transverse tube spacings, longitudinal tube spacings and incoming flow Reynolds numbers through simulation analysis, and construct a mathematical model of the influence of the incoming flow Reynolds number on the resistance coefficient of the microtube array of the microtube pre-cooling heat exchanger: Among them, C f is the resistance coefficient of the microtube array at the corresponding tube pitch; The coefficient is determined by polynomial fitting based on the least squares method; S103. According to the change laws of the resistance coefficient and total pressure loss coefficient of the microtube array of the microtube pre-cooling heat exchanger under different incoming flow Reynolds numbers, construct a mathematical model of the influence of the incoming flow Reynolds number and resistance coefficient of the microtube array of the microtube pre-cooling heat exchanger on the total pressure loss coefficient: Among them, is the total pressure loss coefficient of the microtube array; n is the number of tube rows; the coefficients b1 and b2 are determined by fitting a power function based on the least squares method; S104. Based on the mathematical models constructed in sub-steps S102 and S103, calculate the total pressure loss coefficient of the microtube array of the microtube pre-cooling heat exchanger under different incoming flow Reynolds numbers.

9. A flow resistance equivalent simulation method of a precooling heat exchanger based on the adjustment of a cylindrical double-hole plate according to claim 8, characterized in that, Step S200 at least includes the following sub-steps when implemented: S201. According to the external dimension of the microtube precooling heat exchanger, when the relative plate spacing is 1, preliminarily determine the number of holes N , hole diameter d k , orifice plate thickness , outer cylinder diameter of the orifice plate D 1 , inner cylinder diameter of the orifice plate D 2 , and calculate the equivalent diameter ratio β of the cylindrical double orifice plate; S202. Calculate and determine the range of the inlet Reynolds numbers of the microtube array of the microtube precooling heat exchanger under different flight conditions of the precooling inlet according to the sub-step S101. For the minimum Reynolds number within the range of the sizes of the precooling inlet, when the staggered hole coefficient K is 0, obtain the variation law of the total pressure loss coefficient of the double orifice plate under different equivalent diameter ratios β through simulation analysis. ​ S203. Determine the minimum value of the total pressure loss coefficient of the microtube array of the microtube pre-cooling heat exchanger at different incoming flow Reynolds numbers calculated and determined according to sub-step S104, and the variation law of the total pressure loss coefficient of the double orifice plate at different equivalent diameter ratios obtained in sub-step S202, and determine the appropriate equivalent diameter ratio β of the double orifice plate; β ; S204. Calculate and determine the inlet flow Reynolds numbers of the microtube arrays of the microtube pre-cooling heat exchanger under different flight conditions of the pre-cooling inlet according to the sub-step S101 In the range of the magnitudes, for the maximum Reynolds number among them, when the staggered hole coefficient K is 1, obtain the variation law of the total pressure loss coefficient of the double orifice plate under different relative plate spacings through simulation analysis; S205. Determine the total pressure loss coefficient of the microtube array of the microtube pre-cooling heat exchanger at different Reynolds numbers calculated and determined according to sub-step S104 The maximum value, and the different relative plate spacings obtained in sub-step S204 The total pressure loss coefficient of the double orifice plate at The variation law to determine the appropriate relative plate spacing of the double orifice plate ; S206. According to the determined equivalent diameter ratio of the double orifice plate β , relative plate spacing , maintain the number of openings N , orifice plate thickness , outer cylinder outer diameter initially determined in sub-step S201 unchanged, and calculate and determine the orifice diameter , inner cylinder outer diameter D 2。 10. A method for equivalent simulation of flow resistance of a precooling heat exchanger based on the adjustment of a cylindrical double-hole plate according to claim 9, characterized in that, Step S300 at least includes the following sub-steps when implemented: S301. Based on the geometric parameters of the double-orifice plate determined in step S200, obtain different incoming flow Reynolds numbers through simulation analysis Lower orifice misalignment coefficient of the double-orifice plate K On its total pressure loss coefficient Influence law, construct the incoming flow Reynolds number , Lower orifice misalignment coefficient of the double-orifice plate K On the total pressure loss coefficient Mathematical model of influence: Among them, z 0 、d 1 、c 1 、c 2 The coefficient is determined by fitting with a power function based on the least squares method; S302. For a specific flight condition of the pre-cooled inlet, the incoming flow Reynolds number of the microtube array of the microtube pre-cooler is determined by sub-step S101 ; S303. Determine the resistance coefficient of the microtube array of the microtube precooling heat exchanger according to the typical structural dimensions of the microtube precooling heat exchanger and the mathematical model in sub-step S102 C f ; S304. Then, the total pressure loss coefficient of the microtube array of the microtube pre-cooling heat exchanger is determined by the mathematical model of sub-step S103 ; S305. Maintain the total pressure loss coefficient of the double-hole plate equal to the total pressure loss coefficient of the microtube array of the microtube pre-cooling heat exchanger and determine the misaligned hole coefficient of the double-hole plate according to the mathematical model in sub-step S301 K to achieve the equivalent simulation of the flow resistance of the pre-cooling heat exchanger.

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