High-speed wind tunnel test simulation height solving method

Abstract

The invention belongs to the field of experimental aerodynamics, and discloses a high-speed wind tunnel test simulation height solving method. The high-speed wind tunnel test simulation height solving method comprises the following steps: carrying out a high-speed wind tunnel test; wind tunnel incoming flow static pressure is calculated; and calculating the test simulation height. According to the method for solving the simulation height of the high-speed wind tunnel test, the relational expression between the simulation height of the high-speed wind tunnel test and the static pressure is established through the high-speed wind tunnel test and strict theoretical derivation on the basis of the basic equation of fluid mechanics, test and theoretical support is provided for solving the simulation height of the high-speed wind tunnel test, and the method has engineering application value.

Description

Technical Field

[0001] The invention belongs to the field of experimental aerodynamics, and in particular relates to a method for solving a high-speed wind tunnel test simulation height. Background Art

[0002] Wind tunnel testing is the most widely used, most effective, most mature and most complete experimental aerodynamic research method. Through various types of wind tunnel tests, flow parameters can be obtained, complex flow phenomena can be understood, and a highly reliable basis can be provided for establishing realistic mathematical models in basic research and engineering application research. In particular, large-scale high-speed wind tunnels have played an important role in the fine design of aerodynamic / structure / propulsion integration and aerodynamic characteristics evaluation of advanced large aircraft.

[0003] With the continuous development of aircraft, higher requirements are placed on the simulation parameters of wind tunnel tests. Not only is it required to realize flight Mach number simulation in wind tunnel tests, but also flight altitude simulation is required in the test, considering that changes in flight altitude will lead to significant differences in air density, flow field structure, etc., in order to accurately measure the key aerodynamic characteristic parameters such as lift, drag, heat flow, etc. of the aircraft in different airspaces such as low altitude, medium altitude, and high altitude, evaluate the stability and reliability of the aircraft in high maneuverability, thermal protection and other scenarios, and reduce the risk of aircraft test flights in the entire airspace.

[0004] At present, the existing main high-speed wind tunnels generally use empirical formulas or graph / table methods to evaluate the test simulation altitude. These methods have shortcomings such as incomplete uniformity of empirical formulas and large errors in graph / table methods, and lack of strict theoretical support. These shortcomings seriously restrict the accuracy of high-speed wind tunnel test simulation altitude assessment and have an adverse impact on the safety of aircraft test flights in the entire airspace.

[0005] Currently, there is an urgent need to develop a method for solving the simulation height of high-speed wind tunnel tests. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for solving the simulation height of a high-speed wind tunnel test.

[0007] The high-speed wind tunnel test simulation height solving method of the present invention comprises the following steps: S10. Install the axial detection tube; The axial detection tube is fixed on the middle bracket and set in the high-speed wind tunnel model area. N Static pressure measuring points, connect all static pressure measuring points to the pressure scanning valve through hoses; S20. Conduct high-speed wind tunnel tests; Open the high-speed wind tunnel, set the incoming flow Mach number, and after the flow field stabilizes, use the pressure scanning valve to measure the static pressure of the axial detection tube. ; S30. Calculation of static pressure of wind tunnel inflow p ; According to the static pressure of the axial detection tube Measurement results, calculation of wind tunnel inflow static pressure p : ; S40. Calculate the test simulation height H ; According to the wind tunnel static pressure in step S30 p The calculation results of the test simulation height are calculated H : ; Where, the static pressure of wind tunnel inflow is p The unit is kPa, the test simulation height H The unit is km.

[0008] Furthermore, the calculation test simulation height of step S40 is H The following steps are involved: S41. Establish a wind tunnel static pressure test to simulate the static pressure at an altitude of 0~11km p Test simulation height H The relationship between According to the basic equation of fluid statics: ; In the formula, is the gas density, is the acceleration due to gravity, ; The static pressure of the wind tunnel flow p The derivative of is the test simulation height H The derivative of And, the ideal gas state equation: ; In the formula, T is the gas temperature, R is the gas constant, for air, ; For the test simulation altitude of 0~11km, the gas temperature T Simulated height of the test H Linear change: ; In the formula, Simulate the height for the test H = 0 gas temperature, , K Kelvin is the unit of temperature. is the gas temperatureT Simulated height of the test H The linear rate of change, , combining the above three relationships, we can get the static pressure of the wind tunnel flow p Test simulation height H The differential relationship of: ; To facilitate integration, use the substitution method to change the above formula into: ; Integrating the above formula, we get: ; In the formula, is the integration constant, and the boundary conditions of the above equation are H =0, , solve for the integral constant , and substitute it into the above formula to get: ; The known constant Substituting into the above formula, we get: ; In the formula, p The unit is kPa, H The unit is km. The static pressure of the wind tunnel flow corresponding to the test simulation height of 0~11km p The range is , swap the independent variable and the dependent variable in the above formula to get: ; S42. Establish a wind tunnel static pressure test to simulate the static pressure at an altitude of 11km~25km p Test simulation height H The relationship between For the test simulation altitude of 11km~25km, the gas temperature T Not with test simulation height H changes, according to the gas temperature in step S41 T Simulated height of the test H Linear change relationship, get the test simulation height Gas temperature , the static pressure of step S41 p Test simulation height H The differential relationship degenerates into: ; Integrating the above formula, we get: ; In the formula, is the integration constant, and the boundary conditions of the above equation are hour, , solve for the integral constant , and substitute it into the above formula to get: ; The known constant Substituting into the above formula, we get: ; In the formula, p The unit is kPa, H The unit is km. The static pressure of the wind tunnel flow corresponding to the test simulation height of 11km~25km p The range is , swap the independent variable and the dependent variable in the above formula to get: .

[0009] The method for solving the simulation height of a high-speed wind tunnel test of the present invention is based on the basic equations of fluid mechanics. Through high-speed wind tunnel tests and rigorous theoretical derivation, a relationship between the simulation height of a high-speed wind tunnel test and the static pressure is established, which provides experimental and theoretical support for solving the simulation height of a high-speed wind tunnel test and has engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The present invention is a flowchart of a method for solving the simulation height of a high-speed wind tunnel test. DETAILED DESCRIPTION

[0011] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0012] Example: Figure 1 As shown, the high-speed wind tunnel test simulation height solution method of this embodiment includes the following steps: S10. Install the axial detection tube; The axial detection tube is fixed on the middle bracket and set in the high-speed wind tunnel model area. N Static pressure measuring points, connect all static pressure measuring points to the pressure scanning valve through hoses; S20. Conduct high-speed wind tunnel tests; Open the high-speed wind tunnel, set the incoming flow Mach number, and after the flow field stabilizes, use the pressure scanning valve to measure the static pressure of the axial detection tube. ; S30. Calculation of static pressure of wind tunnel inflow p ; According to the static pressure of the axial detection tube Measurement results, calculation of wind tunnel inflow static pressure p : ; S40. Calculate the test simulation height H ; According to the wind tunnel static pressure in step S30 p The calculation results of the test simulation height are calculated H : ; Where, the static pressure of wind tunnel inflow is p The unit is kPa, the test simulation height H The unit is km.

[0013] Furthermore, the calculation test simulation height of step S40 is H The following steps are involved: S41. Establish a wind tunnel static pressure test to simulate the static pressure at an altitude of 0~11km p Test simulation height H The relationship between According to the basic equation of fluid statics: ; In the formula, is the gas density, is the acceleration due to gravity, ; The static pressure of the wind tunnel flow p The derivative of is the test simulation height H The derivative of And, the ideal gas state equation: ; In the formula, T is the gas temperature, R is the gas constant, for air, ; For the test simulation altitude of 0~11km, the gas temperature T Simulated height of the test H Linear change: ; In the formula, Simulate the height for the test H = 0 gas temperature, , K Kelvin is the unit of temperature. is the gas temperature T Simulated height of the test H The linear rate of change, , combining the above three relationships, we can get the static pressure of the wind tunnel flow p Test simulation height H The differential relationship of: ; To facilitate integration, use the substitution method to change the above formula into: ; Integrating the above formula, we get: ; In the formula, is the integration constant, the boundary condition of the above equation H =0, , solve for the integral constant , and substitute it into the above formula to get: ; The known constant Substituting into the above formula, we get: ; In the formula, p The unit is kPa, H The unit is km. The static pressure of the wind tunnel flow corresponding to the test simulation height of 0~11km p The range is , swap the independent variable and the dependent variable in the above formula to get: ; S42. Establish a wind tunnel static pressure test to simulate the static pressure at an altitude of 11km~25km p Test simulation height H The relationship between For the test simulation altitude of 11km~25km, the gas temperature T Not with test simulation height H changes, according to the gas temperature in step S41 T Simulated height of the test H Linear change relationship, get the test simulation height Gas temperature , the static pressure of step S41 p Test simulation height H The differential relationship degenerates into: ; Integrating the above formula, we get: ; In the formula, is the integration constant, and the boundary conditions of the above equation are hour, , solve for the integral constant , and substitute it into the above formula to get: ; The known constant Substituting into the above formula, we get: ; In the formula, p The unit is kPa, H The unit is km. The static pressure of the wind tunnel flow corresponding to the test simulation height of 11km~25km p The range is , swap the independent variable and the dependent variable in the above formula to get: .

[0014] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes. For those familiar with the art, all features disclosed in the present invention, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way without departing from the principles of the present invention. The present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for solving the simulation height of a high-speed wind tunnel test, characterized in that: The following steps are involved: S10. Install the axial detection tube; The axial detection tube is fixed on the middle bracket and set in the high-speed wind tunnel model area. N Static pressure measuring points, connect all static pressure measuring points to the pressure scanning valve through hoses; S20. Conduct high-speed wind tunnel tests; Open the high-speed wind tunnel, set the incoming flow Mach number, and after the flow field stabilizes, use the pressure scanning valve to measure the static pressure of the axial detection tube. ; S30. Calculation of static pressure of wind tunnel inflow p ; According to the static pressure of the axial probe tube Measurement results, calculation of wind tunnel inflow static pressure p : ； S40. Calculate the test simulation height H ; According to the wind tunnel static pressure in step S30 p The calculation results of the test simulation height are calculated H : ； Where, the static pressure of wind tunnel inflow is p The unit is kPa, the test simulation height H The unit is km.

2. The high-speed wind tunnel test simulation height solution method according to claim 1, characterized in that: The S40 calculation test simulation height H The following steps are involved: S41. Establish a wind tunnel static pressure test to simulate the static pressure at an altitude of 0~11km p Test simulation height H The relationship between According to the basic equation of fluid statics: ； In the formula, is the gas density, is the acceleration due to gravity, ; The static pressure of the wind tunnel flow p The derivative of is the test simulation height H The derivative of And, the ideal gas state equation: ； In the formula, T is the gas temperature, R is the gas constant, for air, ; For the test simulation altitude of 0~11km, the gas temperature T Simulated height of the test H Linear change: ； In the formula, Simulate height for test H = 0 gas temperature, , K Kelvin is the unit of temperature. is the gas temperature T Simulated height of the test H The linear rate of change, , combining the above three relationships, we can get the static pressure of the wind tunnel flow p Test simulation height H The differential relationship of: ； To facilitate integration, use the substitution method to change the above formula into: ； Integrating the above formula, we get: ； In the formula, is the integration constant, and the boundary conditions of the above equation are H =0, , solve for the integral constant , and substitute it into the above formula, we get: ； The known constant Substituting into the above formula, we get: ； In the formula, p The unit is kPa, H The unit is km. The static pressure of the wind tunnel flow corresponding to the test simulation height of 0~11km p The range is , swap the independent variable and the dependent variable in the above formula to get: ； S42. Establish a wind tunnel static pressure test to simulate the static pressure at an altitude of 11km~25km p Test simulation height H The relationship between For the test simulation altitude of 11km~25km, the gas temperature T Not with test simulation height H changes, according to the gas temperature in step S41 T Simulated height of the test H Linear change relationship, get the test simulation height Gas temperature , the static pressure of step S41 p Test simulation height H The differential relationship degenerates into: ； Integrating the above formula, we get: ； In the formula, is the integration constant, and the boundary conditions of the above equation are hour, , solve for the integral constant , and substitute it into the above formula, we get: ； The known constant Substituting into the above formula, we get: ； In the formula, p The unit is kPa, H The unit is km. The static pressure of the wind tunnel flow corresponding to the test simulation height of 11km~25km p The range is , swap the independent variable and the dependent variable in the above formula to get: 。

Images