Calculation method of dynamic pressure peak value during flight of blast wave simulation device simulating aircraft

Abstract

The present invention relates to the field of numerical technology of aircraft dynamics, and discloses a method for calculating the peak value of dynamic pressure during the flight of an aircraft simulated by an explosion wave simulation device, comprising the following steps: measuring the volume, initial atmospheric pressure and final inflation relative pressure of a driving sealing section of the explosion wave simulation device; calculating the final inflation absolute pressure according to the initial atmospheric pressure and the final inflation relative pressure; calculating the overpressure peak value of the shock wave caused by the explosion; calculating the absolute pressure of the airflow in the driving sealing section; calculating the Mach number of the airflow under the action of the shock wave; calculating the total pressure of the airflow according to the Mach number of the airflow and the absolute pressure of the airflow; calculating the static pressure at the outlet of the Laval nozzle; and further calculating the peak value of the dynamic pressure load at the outlet of the Laval nozzle. The present invention uses the explosion wave simulation device as a driving source to calculate the peak value of the dynamic pressure load at the outlet of the Laval nozzle during the flight of the simulated aircraft, and provides technical support for the aircraft mechanism action and strength assessment test.

Description

Technical Field

[0001] The invention relates to the field of numerical technology of aircraft dynamics, and more specifically to a method for calculating the peak value of dynamic pressure during the flight of an aircraft using a blast wave simulation device. Background Art

[0002] During flight, the aerodynamic environment of an aircraft changes with factors such as altitude and flight speed. At present, the simulation of the aerodynamic environment of an aircraft is mainly carried out in wind tunnels. However, due to the limitation of wind tunnel size or function, most of the aircraft mechanism movement and strength assessment tests in wind tunnels are conducted by model tests. Therefore, a considerable part of the aircraft mechanism movement and strength assessment tests are difficult to conduct in wind tunnels.

[0003] In recent years, the use of explosion wave simulation devices, the use of high-pressure gas and explosion-driven modes can generate dynamic loads with long duration and high pressure peaks. By using Laval nozzle conversion, it can simulate the dynamic pressure of the aircraft during flight. It is a new technology for assessing the feasibility and strength of its mechanism action, which makes up for the limitations of similar tests in wind tunnels. The incoming flow generated by the wind tunnel is a steady flow, which mainly simulates the aerodynamic environment during the flight of the aircraft. The density, quality and flow rate of the air are the main parameters of the wind tunnel test. The calculation method of the wind tunnel incoming flow parameters is relatively mature. Unlike the wind tunnel, the incoming flow generated by the combined drive of high-pressure gas and explosion is an unsteady flow. This type of test mainly focuses on the load peak and duration of the incoming flow pressure.

[0004] As mentioned above, there is no relatively mature calculation method for the peak dynamic pressure load in the blast wave simulation device using high-pressure gas and combined drive mode to simulate the flight process of the aircraft. It is difficult to determine the initial conditions of the incoming flow and the peak dynamic pressure load acting on the flight surface, which affects the accuracy of conducting similar experiments. Summary of the invention

[0005] The purpose of the present invention is to provide a method for calculating the dynamic pressure peak value of a blast wave simulation device during the flight of an aircraft. The blast wave simulation device is used as a driving source to accurately calculate the dynamic pressure load peak value at the Laval nozzle outlet during the flight of the simulated aircraft, thereby providing technical support for the aircraft mechanism movement and strength assessment test.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for calculating the peak value of dynamic pressure during flight of an aircraft using a blast wave simulation device comprises the following steps:

[0008] S1. measuring the volume of the driving seal section of the explosion wave simulation device, the initial atmospheric pressure, and the final inflation relative pressure of the driving seal section after the explosive explodes;

[0009] S2. calculating the final inflation absolute pressure of the driving sealing section according to the initial atmospheric pressure and the final inflation relative pressure;

[0010] S3, calculating the overpressure peak value of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device using the charge amount, the volume of the driving seal section and the final inflation absolute pressure;

[0011] S4, calculating the absolute pressure of the airflow in the driving sealing section under the action of the shock wave according to the final inflation absolute pressure and the overpressure peak value;

[0012] S5, calculating the Mach number of the airflow in the driving seal section under the action of the shock wave using the final inflation absolute pressure and the absolute pressure of the airflow;

[0013] S6. Calculating the total pressure of the airflow in the driving seal section according to the Mach number of the airflow and the absolute pressure of the airflow;

[0014] S7, calculating the static pressure at the Laval nozzle outlet according to the total pressure of the airflow and the Mach number of the airflow in the Laval nozzle;

[0015] S8. Calculate the peak value of the dynamic pressure load at the Laval nozzle outlet based on the Laval nozzle outlet static pressure and the Mach number of the Laval nozzle.

[0016] Further, the calculation formula of S2, calculating the final inflation absolute pressure according to the initial atmospheric pressure and the final inflation relative pressure, is specifically:

[0017]

[0018] In the above formula, P 0 is the initial atmospheric pressure, P X is the final inflation relative pressure, P c is the final inflation absolute pressure.

[0019] Further, the S3, using the charge amount 、 The volume of the driving seal section and the final inflation absolute pressure are used to calculate the overpressure peak value of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device. Specifically, it is:

[0020]

[0021] In the above formula, V is the volume of the driving seal section, P c is the final inflation absolute pressure; Q is the charge amount, Δpis the overpressure peak of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device, A p 、B p 、C p All are overpressure peak correlation coefficients.

[0022] Further, the calculation formula of S4, calculating the absolute pressure of the airflow in the driving sealing section under the action of the shock wave according to the final inflation absolute pressure and the overpressure peak, is specifically:

[0023]

[0024] In the above formula, P c is the final inflation absolute pressure, Δp is the overpressure peak of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device, P cc It is the absolute pressure of the airflow in the driving seal section under the action of the shock wave.

[0025] Furthermore, in S5, the calculation formula for calculating the Mach number of the airflow in the driving sealing section under the action of the shock wave using the final inflation absolute pressure and the absolute pressure of the airflow is specifically:

[0026]

[0027] In the above formula, P c is the final inflation absolute pressure, P cc is the absolute pressure of the airflow in the driving seal section under the action of the shock wave, Ma 1 is the Mach number of the airflow in the driving seal section under the action of the shock wave, k is the gas constant.

[0028] Further, the above S6, a calculation formula for calculating the total pressure of the airflow in the driving seal section according to the Mach number of the airflow and the absolute pressure of the airflow, is specifically:

[0029]

[0030] In the above formula, Ma 1 is the Mach number of the airflow in the driving seal section under the action of the shock wave, P z is the total pressure of the airflow in the driving seal section, k is the gas constant.

[0031] Further, the above S7, the calculation formula for calculating the static pressure at the Laval nozzle outlet according to the total pressure of the airflow and the Mach number of the airflow in the Laval nozzle, is specifically:

[0032]

[0033] In the above formula, P z is the total pressure of the airflow in the driving seal section, Ma e is the Mach number of the airflow in the Laval nozzle, P e is the Laval nozzle exit static pressure, k is the gas constant.

[0034] Further, the calculation formula of the peak value of the dynamic pressure load at the Laval nozzle outlet is calculated according to the static pressure at the Laval nozzle outlet and the Mach number of the Laval nozzle in S8, which is specifically:

[0035]

[0036] In the above formula, P e is the Laval nozzle exit static pressure, Ma e is the Mach number of the airflow in the Laval nozzle, P d is the peak value of the dynamic pressure load at the Laval nozzle outlet.

[0037] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0038] The present invention calculates various parameters in the explosion wave simulation device, and then obtains a method for calculating the dynamic pressure peak value during the flight of the simulated aircraft. The method can simulate the shock wave effect of the explosive explosion under specific conditions (such as at the inlet of the Laval nozzle), which is crucial for understanding the physical mechanism and destructive power of the explosion; each step ensures that each calculation from the initial condition to the final result is based on accurate measurement data, thereby improving the reliability and accuracy of the experimental data; by calculating the overpressure peak value of the shock wave and the dynamic parameters of the airflow, key data can be provided for the design of the explosive device, which can help optimize the structure to achieve specific performance goals; by calculating the Mach number, absolute pressure, total pressure of the airflow and the static pressure and dynamic pressure at the nozzle outlet, these steps provide rich data for fluid dynamics research and provide technical support for aircraft mechanism action and strength assessment tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0040] The following is a further description of the method for calculating the peak dynamic pressure during the flight of an aircraft simulated by the explosion wave simulation device of the present invention in conjunction with the accompanying drawings;

[0041] Figure 1 It is a schematic diagram of the overall flow of a method for calculating a dynamic pressure peak value in a blast wave simulation device simulating an aircraft flight process provided by the present invention;

[0042] Figure 2 It is a schematic diagram of a simulated wave explosion device in a method for calculating a dynamic pressure peak value during the flight of an aircraft using an explosion wave simulation device provided by the present invention. DETAILED DESCRIPTION

[0043] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0044] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0045] like Figure 1 and Figure 2 As shown, taking a certain explosion wave simulation device simulating a dynamic pressure peak value during the flight of a certain aircraft as an example, the method for calculating the dynamic pressure peak value during the flight of the aircraft simulated by the explosion wave simulation device provided in an embodiment of the present invention includes the following steps:

[0046] S1, measuring the volume of the driving seal section of the explosion wave simulation device, the initial atmospheric pressure and the final inflation relative pressure of the driving seal section after the explosive explodes; the volume of the driving seal section of a certain explosion wave simulation device in this embodiment V 194.037 m 3 , initial atmospheric pressure P 0 is 0.1MPa, the final inflation relative pressure value P X It is 0.2MPa.

[0047] S2. Calculate the final inflation absolute pressure of the driving seal section according to the initial atmospheric pressure and the final inflation relative pressure, and the calculation method is as follows:

[0048]

[0049] In the above formula, P 0 is the initial atmospheric pressure, P X is the final inflation relative pressure, P c is the final inflation absolute pressure.

[0050] It should be noted that the volume of the driving seal section in the present invention is 194.037 m 3 , the initial atmospheric pressure is 0.1 MPa, Final inflation relative pressure P X 0.2 MPa, Substituting into formula (1), we can get the final absolute pressure of inflation: P c 0.3 MPa.

[0051] S3. Calculate the overpressure peak of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device using the charge amount, the volume of the driving seal section and the final inflation absolute pressure. The calculation method is as follows:

[0052]

[0053] In the above formula, V is the volume of the driving seal section, P c is the final inflation absolute pressure; Q is the charge amount, Δp is the overpressure peak of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device, A p 、B p 、C p are the correlation coefficients of the overpressure peak. Specifically, A p is the coefficient related to the ratio of the cross-sectional area at the detonation point to the cross-sectional area at the measurement point, B p , C p It is a coefficient related to the distance from the measuring point to the detonation point and the equivalent diameter of the cross section of the measuring point, and can be confirmed according to conventional techniques in the art.

[0054] In this embodiment, the charge is 1.2 kg TNT. A p 、B p 、C pare 4.15, -8.65 and 0.59 respectively, and are substituted into formula (2) to obtain the overpressure peak of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device. Δp 0.185 MPa.

[0055] The absolute pressure of the airflow in the driving seal section under the action of the shock wave is calculated according to the final inflation absolute pressure and the overpressure peak value. The calculation method is as follows:

[0056]

[0057] In the above formula, P c is the final inflation absolute pressure, Δp is the overpressure peak of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device, P cc It is the absolute pressure of the airflow in the driving seal section under the action of the shock wave.

[0058] It should be noted that the final inflation absolute pressure P c 0.3 MPa, Peak overpressure of the shock wave caused by the explosion of explosives at the inlet of the Laval nozzle of the blast wave simulation device Δp 0.185 MPa , substituting into formula (3), we can obtain the absolute pressure of the airflow in the driving seal section under the action of the shock wave: P cc 0.485 MPa.

[0059] S5. Calculate the Mach number of the airflow in the driving seal section under the action of the shock wave using the final inflation absolute pressure and the absolute pressure of the airflow. The specific calculation method is as follows:

[0060]

[0061] In the above formula, P c is the final inflation absolute pressure, P cc is the absolute pressure of the airflow in the driving seal section under the action of the shock wave, Ma 1 is the Mach number of the airflow in the driving seal section under the action of the shock wave, k is the gas constant.

[0062] The final inflation absolute pressure P c 0.3 MPa, Absolute pressure of airflow in the driving seal section under the action of shock wave Pcc 0.485 MPa as well as k= Substituting 1.4 into formula (4), we can obtain the Mach number of the airflow in the driving seal section under the action of the shock wave: Ma 1 is 1.24.

[0063] S6. Calculate the total pressure of the airflow in the driving seal section according to the Mach number of the airflow and the absolute pressure of the airflow. The calculation method is as follows:

[0064]

[0065] In the above formula, Ma 1 is the Mach number of the airflow in the driving seal section under the action of the shock wave, P z is the total pressure of the airflow in the driving seal section, k is the gas constant.

[0066] The absolute pressure of the airflow in the driving seal section under the action of the shock wave P cc 0.485 MPa, Mach number of airflow in the driving seal section under the action of shock wave Ma 1 is 1.24 and k= 1.4 Substituting into formula (5), the total pressure of the airflow in the driving seal section can be obtained: P z 1.24 MPa.

[0067] S7. The static pressure at the Laval nozzle outlet is calculated based on the total pressure of the airflow and the Mach number of the airflow in the Laval nozzle. The calculation method is as follows:

[0068]

[0069] In the above formula, P z is the total pressure of the airflow in the driving seal section, Ma e is the Mach number of the airflow in the Laval nozzle, P e is the Laval nozzle exit static pressure, k is the gas constant.

[0070] The Mach number of the airflow in the Laval nozzle is Ma e 2.6, the total pressure of the airflow in the driving seal section of the airflow P z 1.24 MPa as well as k=1.4 Substituting into formula (6) we can get the Laval nozzle exit static pressure P e 0.062 MPa.

[0071] S8. Calculate the peak value of the dynamic pressure load at the Laval nozzle outlet according to the Laval nozzle outlet static pressure and the Laval nozzle Mach number. The calculation method is as follows:

[0072]

[0073] In the above formula, P e is the Laval nozzle exit static pressure, Ma e is the Mach number of the airflow in the Laval nozzle, P d is the peak value of the dynamic pressure load at the Laval nozzle outlet.

[0074] Laval nozzle outlet static pressure P e 0.062 MPa, Mach number of the airflow in the Laval nozzle Ma e 2.6 and k =1.4 is substituted into formula (7) to obtain the peak value of the dynamic pressure load at the Laval nozzle outlet. P d 0.293 MPa.

[0075] The present invention can also provide a blast wave simulation device to simulate a dynamic pressure peak value calculation system during the flight of an aircraft, which is used to execute the above method.

[0076] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0077] The remaining technical features in this embodiment can be flexibly selected by those skilled in the art according to actual conditions to meet different specific practical needs. However, it is obvious to those skilled in the art that it is not necessary to adopt these specific details to implement the present invention. In other examples, in order to avoid confusing the present invention, the well-known components, structures or parts are not specifically described, which are all within the technical protection scope defined by the technical solution claimed for protection in the claims of the present invention.

[0078] Modifications and changes made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the scope of protection of the claims attached to the present invention. In the above description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details are not necessary to practice the present invention. In other examples, in order to avoid confusing the present invention, well-known technologies, such as specific construction details, operating conditions and other technical conditions, are not specifically described.

[0079] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for calculating the peak dynamic pressure of a blast wave simulation device during the flight of an aircraft, characterized in that: The following steps are involved: S1. measuring the volume of the driving seal section of the explosion wave simulation device, the initial atmospheric pressure, and the final inflation relative pressure of the driving seal section after the explosive explodes; S2. calculating the final inflation absolute pressure of the driving sealing section according to the initial atmospheric pressure and the final inflation relative pressure; S3, calculating the overpressure peak value of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device using the charge amount, the volume of the driving seal section and the final inflation absolute pressure; S4, calculating the absolute pressure of the airflow in the driving sealing section under the action of the shock wave according to the final inflation absolute pressure and the overpressure peak value; S5, calculating the Mach number of the airflow in the driving seal section under the action of the shock wave using the final inflation absolute pressure and the absolute pressure of the airflow; S6. Calculating the total pressure of the airflow in the driving seal section according to the Mach number of the airflow and the absolute pressure of the airflow; S7, calculating the static pressure at the Laval nozzle outlet according to the total pressure of the airflow and the Mach number of the airflow in the Laval nozzle; S8. Calculate the peak value of the dynamic pressure load at the Laval nozzle outlet based on the Laval nozzle outlet static pressure and the Mach number of the Laval nozzle.

2. The method for calculating the peak dynamic pressure during the flight of an aircraft simulated by the explosion wave simulation device according to claim 1 is characterized in that: The calculation formula of S2, calculating the final inflation absolute pressure according to the initial atmospheric pressure and the final inflation relative pressure, is specifically: ， In the above formula, P 0 is the initial atmospheric pressure, P X is the final inflation relative pressure, P c is the final inflation absolute pressure.

3. The method for calculating the peak value of dynamic pressure during the flight of an aircraft simulated by the explosion wave simulation device according to claim 1, characterized in that: S3, using the charge 、 The volume of the driving seal section and the final inflation absolute pressure are used to calculate the overpressure peak value of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device. Specifically, it is: ， In the above formula, V is the volume of the driving seal section, P c is the final inflation absolute pressure; Q is the charge amount, Δp is the overpressure peak of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device, A p 、B p 、C p All are overpressure peak correlation coefficients.

4. The method for calculating the peak dynamic pressure during the flight of an aircraft simulated by the explosion wave simulation device according to claim 1, characterized in that: The S4, a calculation formula for calculating the absolute pressure of the airflow in the driving sealing section under the action of the shock wave according to the final inflation absolute pressure and the overpressure peak, is specifically: P cc =P c +Δp （3）， In the above formula, P c is the final inflation absolute pressure, Δp is the overpressure peak of the shock wave caused by the explosion of the explosive at the inlet of the Laval nozzle of the explosion wave simulation device, P cc It is the absolute pressure of the airflow in the driving seal section under the action of the shock wave.

5. The method for calculating the peak value of dynamic pressure during the flight of an aircraft simulated by an explosion wave simulation device according to claim 1, characterized in that: The S5, using the final inflation absolute pressure and the absolute pressure of the airflow to calculate the Mach number of the airflow in the driving seal section under the action of the shock wave, is specifically: ， In the above formula, P c is the final inflation absolute pressure, P cc is the absolute pressure of the airflow in the driving seal section under the action of the shock wave, Ma 1 is the Mach number of the airflow in the driving seal section under the action of the shock wave, k is the gas constant.

6. The method for calculating the peak value of dynamic pressure during the flight of an aircraft simulated by an explosion wave simulation device according to claim 1, characterized in that: The above S6, a calculation formula for calculating the total pressure of the airflow in the driving seal section according to the Mach number of the airflow and the absolute pressure of the airflow, is specifically: ， In the above formula, Ma 1 is the Mach number of the airflow in the driving seal section under the action of the shock wave, P z is the total pressure of the airflow in the driving seal section, k is the gas constant.

7. The method for calculating the peak value of dynamic pressure during flight of an aircraft simulated by an explosion wave simulation device according to claim 1, characterized in that: The above S7, the calculation formula for calculating the static pressure at the Laval nozzle outlet according to the total pressure of the airflow and the Mach number of the airflow in the Laval nozzle, is specifically: ， In the above formula, P z is the total pressure of the airflow in the driving seal section, Ma e is the Mach number of the airflow in the Laval nozzle, P e is the Laval nozzle exit static pressure, k is the gas constant.

8. The method for calculating the peak value of dynamic pressure during the flight of an aircraft simulated by an explosion wave simulation device according to claim 1, characterized in that: The above S8, the calculation formula for calculating the peak value of the dynamic pressure load at the Laval nozzle outlet according to the Laval nozzle outlet static pressure and the Mach number of the Laval nozzle, is specifically: ， In the above formula, P e is the Laval nozzle exit static pressure, Ma e is the Mach number of the airflow in the Laval nozzle, P d is the peak value of the dynamic pressure load at the Laval nozzle outlet.

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