Rocket sled aerodynamic characteristic evaluation method based on meteorological environment multi-factor coupling effect

Abstract

The invention relates to a rocket sled aerodynamic characteristic evaluation method based on a meteorological environment multi-factor coupling effect, and solves the problem of deviation between a simulation evaluation result and an actual test result due to the fact that factors are not effectively combined in an existing evaluation technology. The method comprises the following steps: step 1, acquiring multi-dimensional meteorological data; 2, adjusting the air density; step 3, adjusting a viscosity coefficient; 4, determining the mass fraction of water vapor in the air; and 5, establishing a wet air material. 6, the relative running speed of the rocket sled and the air is determined; 7, solving the steady state of the aerodynamic characteristics of the whole trajectory of the rocket sled; and 8, verifying and correcting the model. The method has the advantages that the aerodynamic characteristics of the rocket sled can be accurately reproduced; two factors, namely air density and dynamic viscosity coefficient, which have great influence on the aerodynamic characteristics of the rocket sled are comprehensively considered; a wet air material model is established, and compared with a previous dry air model, the evaluation precision is higher.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of military target range test technology, and mainly relates to rocket sled test technology, and particularly relates to a rocket sled aerodynamic characteristic evaluation method based on meteorological environment multi-factor coupling. BACKGROUND

[0002] The rocket sled is a large-scale ground high-dynamic simulation test platform using a rocket engine as power to realize performance test of a loaded weapon system or key component in actual working process speed, overload, attitude, end effect, etc. on a special precise slide rail. The rocket sled is not affected by the shape size of a test product, has low cost compared with flight test, is highly repeatable, and has rich test data, and is widely applied to the fields of aviation, aerospace, weapons, ships and electronics.

[0003] Traditional rocket sled aerodynamic characteristic evaluation mainly depends on CFD simulation software, has the advantages of high efficiency and low cost, and in calculation, only pressure and temperature of the same period of the previous year of a test date are used as input boundaries to estimate the aerodynamic characteristics of the rocket sled on the test day. However, in actual application, humidity, wind direction and wind speed changes of external meteorological environment are also important factors affecting the aerodynamic performance of the rocket sled. In simulation, these parameters affect the aerodynamic behavior through different mechanisms, so as to change the aerodynamic performance of the rocket sled. For example, the increase of humidity will reduce the air density, the dynamic viscosity coefficient and the aerodynamic resistance. Changes of wind direction and wind speed will change the pressure distribution and flow velocity distribution of the surface of the rocket sled. Especially for the single-track rocket sled, the aerodynamic resistance accounts for a large proportion in the test trajectory design, and the influence is more obvious. The existing evaluation technology fails to effectively combine these factors, resulting in deviation between the simulation evaluation result and the actual test result. SUMMARY

[0004] The present application provides a rocket sled aerodynamic characteristic evaluation method considering the coupling of ground meteorological parameters of a rocket sled test site, which effectively improves the accuracy of rocket sled aerodynamic characteristic evaluation by real-time collection and analysis of meteorological data and dynamic adjustment of the evaluation model.

[0005] The present application is realized by the following technical solutions:

[0006] A rocket sled aerodynamic characteristic evaluation method based on meteorological environment multi-factor coupling, comprising the following steps:

[0007] Step 1: Multi-dimensional meteorological data collection.

[0008] A field meteorological instrument, a portable comprehensive meteorological observer, is used to collect data at the rocket sled test slide rail facility in real time and obtain parameters of atmospheric pressure p, air temperature T, relative humidity RH, wind speed v wind , and wind direction θ through processing.

[0009] Step 2: Adjustment of air density.

[0010] Atmospheric pressure p, air temperature T, relative humidity RH, etc. will affect the air density. The air density increases with the increase of atmospheric pressure, decreases with the increase of air temperature, and decreases with the increase of relative humidity. The specific calculation method of air density is:

[0011] (1) Solve the dry air density

[0012] The rocket sled runs in the near-earth environment, and the dry air adopts the ideal gas assumption. The calculation formula of the dry air density ρ d in this altitude range is obtained by the ideal gas state equation

[0013]

[0014] In the formula, M d = 0.0289647 kg / mol is the molar mass of dry air, R0 = 8.314 J / (mol·K) is the ideal gas constant, p is the atmospheric pressure, and T is the air temperature.

[0015] (2) Solve the saturated water vapor density

[0016] The saturated water vapor density ρ v is solved by the IAPWS-95 formula, and the total Helmholtz free energy is represented as

[0017] α(ρ s ,T)=α 0 (ρ s ,T)+α r (ρ s ,T) (2)

[0018] In the formula, α 0 (ρ s ,T) is the ideal gas part, and α r (ρ s ,T) is the remaining part, which is a polynomial function of δ and τ.

[0019] The calculation formula of α 0 (ρ s ,T) is

[0020]

[0021] In the formula, ρ0 is the reference density, and f(T) is a function related only to temperature.

[0022] The calculation formula of α r (ρ s ,T) is

[0023]

[0024] δ = p s / p c (5)

[0025] τ = T c / T (6)

[0026] where n is the number of terms, n i , d i , t i are constants obtained by fitting experimental data, p c is the critical density of water vapor, T c is the critical temperature of water vapor;

[0027] (3) Solve the wet air density

[0028] The wet air density p is obtained from the dry air density p d , the saturated water vapor density p s and the relative humidity RH as

[0029] p = p d (1 - RH) + p s x RH (7)

[0030] Step 3: Adjustment of the viscous coefficient.

[0031] The expression of the dynamic viscous coefficient μ of air is

[0032] μ = p

[0033] where v is the kinematic viscosity coefficient.

[0034] Atmospheric pressure changes the dynamic viscous coefficient by affecting the air density; the effect of air temperature on the dynamic viscous coefficient can be calculated using the Sutherland formula; due to the fact that water vapor molecules are lighter than the main components of air, namely nitrogen and oxygen, the increase of relative humidity will reduce the air density and the efficiency of intermolecular momentum exchange, resulting in a decrease in the dynamic viscous coefficient, but the change is very small, generally <1%.

[0035] Step 4: Determination of the water vapor mass fraction in air.

[0036] (1) Determine the saturated vapor pressure

[0037] Solve p

[0038]

[0039] where p sSaturation vapor pressure, unit mmHg, A, B, C are the corresponding material constants, water Antoine equation constants A = 8.07131, B = 1730.63, C = 233.426, T is the temperature in Celsius.

[0040] (2) Calculate the actual vapor pressure

[0041] Defined by the relative humidity RH The actual vapor pressure p can be obtained v = RH x p s .

[0042] (3) Calculate the amount fraction of water vapor

[0043] Because the water vapor partial pressure in the atmosphere is small, the error caused by treating it as an ideal gas is within an acceptable range, so the humid air is assumed to be an ideal gas mixture, and according to the ideal gas state equation pV = nRT, the gas partial pressure ratio is equal to the amount ratio under the same temperature and pressure. Then the water vapor amount fraction y is

[0044]

[0045] (4) Calculate the water vapor mass fraction

[0046] The calculation formula of the water vapor mass fraction is

[0047]

[0048] In the formula, M v ≈ 18 g / mol is the molar mass of water vapor; M ≈ 28.9647 g / mol is the molar mass of air.

[0049] Step 5: Establishment of humid air material.

[0050] In each simulation software, users can define materials, and in step 4 it has been mentioned that the humid air is assumed to be an ideal gas mixture, therefore, a new mixture of air (ideal gas) and water vapor (ideal gas) is defined as humid air, and the mass fraction is used as a parameter to describe the proportion of each component, and the water vapor mass fraction w obtained in step 4 is then the mass fraction of air is 1-w.

[0051] Step 6: Determination of the relative running speed of the rocket sled and the air.

[0052] Wind speed directly affects the actual relative motion speed of the rocket sled and the air, changes the flow speed distribution and direction. The wind direction determines the incoming flow direction, affects the surface pressure distribution and boundary layer development of the rocket sled, and thus adjusts the lift and drag.

[0053] Because the rocket sled runs on the high-precision rocket sled slide rail with the geometric feature of the space straight line tangent to the earth, the running feature is mainly translation and slightly rolling, so the rolling motion of the rocket sled is ignored, and the Cartesian coordinate system is used to describe the motion of the rocket sled.

[0054] In the formula, the positive direction of the x-axis is from south to north, the positive direction of the y-axis is vertically upward, the direction of the z-axis is determined according to the right-hand rule, and the position of the origin is different for each type of rocket sled. If the rocket sled has a test object such as a warhead, a seeker, an airplane, etc. exposed outside, the centroid of the test object is taken as the origin of the coordinate system. If the rocket sled has no test object, the midpoint of the lowermost line of the windward surface of the head of the rocket sled is taken as the origin. It is assumed that the running direction of the rocket sled is -x direction, the speed is v sled , the wind speed is v wind , and the wind direction is θ, with 0° for the north direction, clockwise rotation, 90°, 180° and 270° for the east, south and west directions respectively.

[0055] In the process of aerodynamic simulation, the fixed grid method is usually used to achieve the simulation of the aerodynamic characteristics of the rocket sled by setting the air movement speed, that is, the actual relative running speed of the rocket sled and the air, so that the actual relative running speed of the rocket sled and the air is calculated as follows:

[0056]

[0057] Step 7: Steady-state solution of full trajectory aerodynamic characteristics of the rocket sled.

[0058] After adjusting the above parameters, the steady-state solution of the test full trajectory characteristics of the rocket sled flow field is carried out. The establishment principle of the far field of the rocket sled is to consider the ground effect and retain the track of the rocket sled and the ground shape. The numerical solution method is as follows: the SST turbulence model is used for the turbulence model, the finite volume method center difference format is used for spatial discretization, and the second-order backward difference Euler format is used for time discretization. The actual relative running speed, static pressure, static temperature and turbulence intensity of the rocket sled and the air are given at the inlet, and the supersonic boundary condition is given at the outlet; the adiabatic, free slip boundary condition is given at the far field; the adiabatic, no-slip boundary condition is given at the wall surface of the ground and the slide rail facilities, and the speed is given; the adiabatic, no-slip boundary condition is given at the wall surface of the rocket sled; the speed, static pressure, static temperature and turbulence intensity are given as the initial conditions. When the convergence residual error is reduced to 10 -5 The following or monitoring quantities are considered to be converged when they remain at the same numerical level for a long time step.

[0059] Step 8: Model verification and correction.

[0060] When the rocket sled test is implemented, the photoelectric theodolite is used to track and measure the image of the running process of the rocket sled, the photoelectric theodolite virtual intersection method is used to process to obtain the full-range speed-time curve of the rocket sled test trajectory, the static pressure sensor is arranged at a suitable position on the surface of the rocket sled, the full-range static pressure-time curve of the measuring point is obtained by using the telemetry method, and the simulation model is verified based on the measured static pressure data to determine whether the accuracy requirement is met.

[0061] (1) The data of the static pressure of the measuring point changing with time obtained in the test is filtered to obtain the data curve of the static pressure measuring point after deburring.

[0062] (2) The full-range speed-time curve of the rocket sled is compared, and whether the obtained static pressure data conforms to the theoretical rule that the static pressure increases with the increase of the running speed of the rocket sled is analyzed to confirm the effectiveness of the test static pressure data.

[0063] (3) The simulation result of the static pressure of the measuring point after the simulation model parameters are adjusted is mapped with the time-speed relationship of the trajectory process to establish the relationship curve of the simulation data static pressure and time.

[0064] (4) The relationship curve of the measuring point test data and time is compared with the relationship curve of the simulation data and time, and the error R of the simulation is obtained to determine whether the simulation model meets the accuracy requirement of R≤10%. The error R calculation formula is

[0065]

[0066] In the formula, p sim is the simulation static pressure of the measuring point, and p exp is the test measured static pressure of the measuring point.

[0067] (5) If there is deviation between the model and the actual situation, the related parameters are further adjusted, and multiple iterations are performed until the simulation data and the test data are consistent enough.

[0068] The implementation of the present application also lies in that when the simulation shape of the rocket sled is established, the consistency of the head of the rocket sled compared with the design model should be ensured, and the overall structure appearance size of the rear part of the rocket sled remains unchanged, so that the simulation accuracy of the static pressure measuring point is improved.

[0069] The implementation of the present application also lies in that the machining accuracy of the rocket sled should be ensured to ensure the consistency of the actual test rocket sled and the design model, so that the influence of the machining accuracy on the static pressure of the measuring point is reduced.

[0070] The implementation of the present application also lies in that in the rocket sled test, the selection principle of the static pressure measuring point is the upper surface of the rocket sled, so that the track oil dirt or track coating molten material splashing in the running process of the rocket sled is prevented, and the test failure caused by the blocking of the measuring point is prevented.

[0071] Compared with the prior art, the present application has the advantages that:

[0072] 1. The rocket sled aerodynamic characteristic evaluation method based on the multi-factor coupling of meteorological environment is proposed to solve the problem that the influence of the test meteorological environment is not fully considered in the conventional rocket sled aerodynamic characteristic evaluation method, and the accurate reproduction of the rocket sled aerodynamic characteristics can be realized.

[0073] 2. The rocket sled aerodynamic characteristic evaluation method based on the multi-factor coupling of meteorological environment is proposed to solve the problem that the influence of the test meteorological environment is not fully considered in the conventional rocket sled aerodynamic characteristic evaluation method, and the accurate reproduction of the rocket sled aerodynamic characteristics can be realized.

[0074] 3. The rocket sled aerodynamic characteristic evaluation method based on the multi-factor coupling of meteorological environment is proposed to solve the problem that the influence of the test meteorological environment is not fully considered in the conventional rocket sled aerodynamic characteristic evaluation method, and the accurate reproduction of the rocket sled aerodynamic characteristics can be realized.

[0075] 4. The rocket sled aerodynamic characteristic evaluation method based on the multi-factor coupling of meteorological environment is proposed to solve the problem that the influence of the test meteorological environment is not fully considered in the conventional rocket sled aerodynamic characteristic evaluation method, and the accurate reproduction of the rocket sled aerodynamic characteristics can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0076] Figure 1 is a schematic diagram of the rocket sled Cartesian coordinate system in the case of a test product of the present application;

[0077] Figure 2 is a schematic diagram of the rocket sled Cartesian coordinate system and the position of the measuring point in the case of no test product of the present application;

[0078] Figure 3 is a schematic diagram of the wind direction, wind speed and the running direction and speed of the rocket sled of the present application;

[0079] Figure 4 is a schematic diagram of the position of the measuring point in Example 2 of the present application. DETAILED DESCRIPTION

[0080] As shown in Figures 1-4 , the rocket sled aerodynamic characteristic evaluation method considering the ground meteorological parameters is provided, the real-time meteorological data of the test is collected and analyzed by the portable field meteorological instrument, the rocket sled aerodynamic characteristic simulation evaluation model is dynamically adjusted according to the meteorological data, the rocket sled aerodynamic characteristics are simulated, a new method for the reproduction of the rocket sled test aerodynamic characteristics is provided, and the evaluation accuracy is improved. The embodiments of the present application will be described in detail below with reference to the drawings.

[0081] Example 1

[0082] A rocket sled as shown in Figure 2 , the rocket sled aerodynamic characteristic evaluation method of the present application is used to evaluate the aerodynamic characteristics of the rocket sled.

[0083] The meteorological data measured at the rocket sled track at the time of the test were as follows: air pressure 85110 Pa, air temperature 23.4℃, relative humidity 17%, wind speed 1.3 m / s, and wind direction 259°.

[0084] The air density calculated using the method of this invention is 0.9975 kg / m³. 3 The dynamic viscosity coefficient is 1.8278 × 10⁻⁶. -5 Pa·s, the mass fraction of water vapor in the air is 0.36%, the mass fraction of air is 99.64%, v x =v sled +0.25m / s, v y =0m / s, v z =1.28m / s.

[0085] Based on the calculation results, adjust the simulation parameters and establish a humid air material model to calculate the aerodynamic characteristics of the full-trajectory rocket skid. Select two hydrostatic measurement points, p1 and p2, as follows: Figure 2 As shown, the static pressure at each measuring point under each working condition is obtained, and the time-velocity relationship is mapped based on the full-range velocity-time curve of the rocket skid obtained by the photoelectric theodolite (with the launch time of the rocket skid as the zero point) to obtain the static pressure data of each measuring point at different ballistic moments.

[0086] During the experiment, two static pressure measuring points were set up at the same locations as in the simulation on the windward side of the rocket sled. Static pressure data at these points were obtained using static pressure sensors and telemetry devices. The static pressure at each measuring point was then filtered to obtain data on the change in static pressure over time.

[0087] The comparison between the simulation data and the experimental data is shown in Table 1. It can be seen that the maximum static pressure simulation error is 9.02%, which meets the requirement of static pressure error ≤10%.

[0088] Table 1 Comparison of simulated and measured static pressure values ​​at measurement points in Example 1

[0089]

[0090]

[0091] Example 2:

[0092] The shape of a rocket skid and the location of two static pressure measuring points are as follows: Figure 4 As shown, the aerodynamic characteristics of this rocket skid are evaluated using the evaluation method of the present invention.

[0093] The meteorological data measured at the rocket sled track at the time of the test were as follows: air pressure 85960Pa, air temperature 20.8℃, relative humidity 47%, wind speed 10m / s, and wind direction 272°.

[0094] The air density is 1.0134 kg / m 3 , the dynamic viscosity coefficient is 1.8236*10 -5 Pa*s, the water vapor mass fraction in the air is 0.83%, the air mass fraction is 99.17%, v x = v sled -0.35 m / s, v y =0 m / s, and v z =9.99 m / s.

[0095] According to the calculation results, each simulation parameter is adjusted, and a wet air material is established, and the aerodynamic characteristics of the full trajectory rocket sled are calculated. The simulation static pressure and the test measured static pressure at different times of two measuring points are obtained, as shown in Table 2. It can be seen that the maximum error of the static pressure simulation is 9.56%, which meets the requirement of the static pressure error ≤10%.

[0096] Table 2 Comparison of static pressure simulation values and measured values of measuring points in Example 2

[0097]

[0098]

[0099] When the rocket sled test is used, the method improves the evaluation accuracy of the aerodynamic characteristics of the rocket sled, lays a foundation for the accurate trajectory design of the rocket sled test, and provides a performance test environment with higher consistency with the actual working environment for the tested product.

Claims

1. A method for evaluating the aerodynamic characteristics of a rocket sled based on the multi-factor coupling of meteorological environment, characterized in that: Comprising the following steps: Step 1: Multidimensional meteorological data acquisition Real-time data acquisition and processing at the rocket sled test track facility yielded atmospheric pressure p, air temperature T, relative humidity RH, and wind speed v. wind Wind direction θ parameter; Step 2: Adjustment of air density The specific calculation method of air density is: (1) Solve the dry air density Dry air adopts the ideal gas assumption, and the dry air density p in the altitude range is obtained by the ideal gas state equation d The calculation formula is In the formula, M d is the molar mass of dry air, R0is the ideal gas constant, p is the atmospheric pressure, and T is the air temperature. (2) Solve the saturated water vapor density Solving the IAPWS-95 equation for saturated water vapor density p v The total Helmholtz free energy is represented as a(p s ,T) = a 0 (p s ,T) + a r (p s ,T) (2) In the formula, α 0 (ρ s T) represents the ideal gas part, α r (ρ s The remainder (T) is a polynomial function in terms of δ and τ; a 0 (ρ s The formula for calculating (p, T) is In the formula, ρ0 is the reference density, and f(T) is a function related only to temperature; a r (ρ s The formula for calculating (p, T) is δ = p s / p c (5) T = T c T (6) where n is the number of terms, n i , d i , t i are constants obtained by fitting experimental data, p c is the critical density of water vapor, T c is the critical temperature of water vapor; (3) Solve the wet air density The density of dry air ρ d The density of saturated water vapor ρ s and the relative humidity RH is given by the density of moist air ρ p = p d (1 - RH) + p s x RH (7) Step 3: Adjustment of viscosity coefficient The expression of the dynamic viscosity coefficient μ of air is μ = ρν (8) In the formula, ν is the kinematic viscosity coefficient. Atmospheric pressure changes the dynamic viscosity coefficient by affecting the air density; the influence of air temperature on the dynamic viscosity coefficient is calculated by using the Sutherland formula; Step 4: Determination of the mass fraction of water vapor in air. (1) Determine the saturated vapor pressure Solve by using the Antoine equation where p s is the saturated vapor pressure, A, B, C are the corresponding substance constants, and T is the temperature in degrees Celsius; (2) Calculate the actual vapor pressure Defined by the relative humidity RH The actual vapor pressure p v = RH x p s ; (3) Solve the mass fraction of water vapor Assuming that the wet air is an ideal gas mixture, according to the ideal gas state equation pV = nRT, under the same temperature and pressure, the gas partial pressure ratio is equal to the amount of substance ratio, so the water vapor amount of substance fraction y is (4) Calculate the mass fraction of water vapor The calculation formula of the mass fraction of water vapor is where M v ≈ 18 g / mol, the molar mass of water vapor; M ≈ 28.9647 g / mol, the molar mass of air; Step 5: Establishment of wet air material In each simulation software, users can define materials, as described in step 4, assuming that the wet air is an ideal gas mixture, therefore, the newly defined mixture of air and water vapor is wet air, using the mass fraction as a parameter to describe the proportion of each component, the mass fraction of water vapor w has been solved in step 4, then the mass fraction of air is 1-w; Step 6: Determination of the relative running speed of the rocket sled and air Ignoring the rolling motion of the rocket sled, the motion of the rocket sled is described by using the Cartesian coordinate system; Wherein, the positive direction of x-axis is from south to north, the positive direction of y-axis is vertically upward, the direction of z-axis is determined according to the right-hand rule, and the position of the origin is different for each type of rocket sled. If the rocket sled has a test product exposed outside, the centroid of the test product is taken as the origin of the coordinate system. If the rocket sled has no test product, the midpoint of the lowermost line of the windward surface of the head of the rocket sled is taken as the origin. It is assumed that the running direction of the rocket sled is -x direction, the speed is v sled ; the wind speed is v wind ; the wind direction is θ, the north direction is 0°, the clockwise rotation, the east, south and west are 90°, 180° and 270° respectively; In the process of aerodynamic simulation, the fixed grid method is used, the aerodynamic characteristics of the rocket sled are simulated by setting the air motion speed, the set air motion speed is the actual relative running speed of the rocket sled and air, therefore, the actual relative running speed of the rocket sled and air is calculated as: Step 7: Steady-state solution of the full trajectory aerodynamic characteristics of the rocket sled After adjusting the parameters described in steps 1-6, steady-state solutions of the rocket sled flow field are carried out for test full trajectory characteristic working conditions; the establishment principle of the far field of the rocket sled is to consider the ground effect and retain the track of the rocket sled and the ground shape; the numerical solution method is as follows: the SST turbulence model is adopted for the turbulence model, the finite volume method center difference format is adopted for spatial discretization, and the Euler format of the second-order backward difference is adopted for time discretization; the actual relative running speed of the rocket sled and air, static pressure, static temperature and turbulence intensity are given at the inlet, supersonic boundary conditions are given at the outlet; the adiabatic and free slip boundary conditions are given at the far field; the adiabatic and non-slip boundary conditions are given at the wall surface of the ground and the slide rail facilities, and the speed is given; the adiabatic and non-slip boundary conditions are given at the wall surface of the rocket sled; the speed, static pressure, static temperature and turbulence intensity are given for the initial conditions; when the convergence residual error is reduced to 10 -5 The following or monitoring quantities are considered to be converged when they remain at the same numerical level for a long time step; Step 8: Model verification and correction When the rocket sled test is implemented, the optical theodolite tracking measurement image of the rocket sled running process is used, the virtual intersection method of the optical theodolite is used to process to obtain the full-range speed-time curve of the rocket sled test trajectory, static pressure sensors are arranged at appropriate positions on the surface of the rocket sled, and the full-range static pressure-time curve of the measurement point is obtained by using the telemetry method, and the measured static pressure data is used as the basis to verify the simulation model, and determine whether the accuracy requirements are met.

2. The method for evaluating the aerodynamic characteristics of a rocket sled based on the multi-factor coupling of meteorological environment according to claim 1, characterized in that: The implementation steps of step 8 are: (1) Filter the data of the static pressure of the measurement point changing with time obtained by the test, and obtain the data curve of the static pressure measurement point after deburring processing; (2) Compare the full-range speed-time curve of the rocket sled, analyze whether the obtained static pressure data conforms to the theoretical law that the static pressure increases with the increase of the running speed of the rocket sled, to confirm the effectiveness of the test static pressure data; (3) Map the simulation results of the static pressure of the measurement point after adjusting the parameters of the simulation model with the trajectory process, and establish the relationship curve of the simulation data static pressure and time; (4) The error R is calculated by comparing the test data and the simulation data to determine whether the simulation model meets the accuracy requirement of R≤10%. where p sim is the simulated static pressure at the measurement point, p exp is the measured static pressure at the measurement point; (5) If there is a deviation between the model and the actual situation, the related parameters are further adjusted and the iteration is carried out for multiple times until the simulation data and the test data are consistent enough.

3. The method for evaluating the aerodynamic characteristics of a rocket sled based on the multi-factor coupling of meteorological environment according to claim 1, characterized in that When the simulation shape of the rocket sled is established, the consistency of the head of the rocket sled with the design model should be ensured, and the overall structure of the rear part of the rocket sled remains unchanged to improve the simulation accuracy of the static pressure measuring point.

4. The method for evaluating the aerodynamic characteristics of a rocket sled based on the multi-factor coupling of meteorological environment according to claim 1, characterized in that: The machining precision of the rocket sled should be ensured to ensure the consistency of the actual test rocket sled and the design model, so as to reduce the influence of the machining precision on the static pressure of the measuring point.

5. The method for evaluating the aerodynamic characteristics of a rocket sled based on the multi-factor coupling of meteorological environment according to claim 1, characterized in that In the rocket sled test, the principle of selecting the static pressure measuring point is the upper surface of the rocket sled to prevent the track oil or track coating molten material from splashing and blocking the measuring point during the operation of the rocket sled, causing the test to fail.

6. The method for evaluating the aerodynamic characteristics of a rocket sled based on the multi-factor coupling of meteorological environment according to claim 1, characterized in that: Step 1 uses a portable integrated weather observer, a field weather instrument, to collect weather data.

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