CN-122016230-A - Backpack embedded type air inlet channel wide-area flow coefficient test simulation method

Abstract

The application belongs to an air inlet channel wind tunnel test method and discloses a backpack embedded air inlet channel wide-area flow coefficient test simulation method, which comprises the steps that when the air inlet channel flow is controlled at the lower boundary, air inlet channel pore plates with different flow rates which can be replaced are arranged in the air inlet channel, so that the effective control of the air inlet channel flow lower boundary is realized; when the upper boundary control is carried out on the flow of the air inlet, the inner flow channel suction device is arranged on the air inlet to realize the effective control of the upper boundary of the flow of the air inlet, the replaceable air inlet lip static pressure and dynamic pressure measuring modules and the wall static pressure measuring modules distributed along the air inlet are arranged to finish the measurement of the bulge pressure of the air inlet lip, and the total static pressure measuring rake is arranged at the tail end of the air inlet to finish the calculation of the flow coefficient and the internal resistance so as to realize the quantitative analysis of the performance of the air inlet.

Inventors

• Yang Lejie
• MA SHANG
• XU YANGFAN
• LIU DAWEI
• WU JIFEI
• LI GUOSHUAI
• HUANG ZHENXIN
• YAN CHUNHUI

Assignees

• 中国空气动力研究与发展中心高速空气动力研究所

Dates

Publication Date

20260512

Application Date

20260410

Claims (9)

1. 1. The backpack embedded type air inlet channel wide-area flow coefficient test simulation method is characterized by comprising the following steps of: When the upper boundary control is carried out on the flow of the air inlet, the inner flow channel suction device is arranged on the air inlet to realize the effective control of the upper boundary of the flow of the air inlet; the method comprises the steps of setting up a replaceable inlet lip static pressure and dynamic pressure measuring module and a wall static pressure measuring module distributed along the inlet to measure the pressure of the inlet lip bulge, and setting up a total static pressure measuring rake at the tail end of the inlet to calculate the flow coefficient and internal resistance so as to realize quantitative analysis of the performance of the inlet.
2. 2. The backpack embedded type air inlet channel wide-area flow coefficient test simulation method according to claim 1, wherein the inner flow channel suction device comprises an ejector (4) and an air conveying pipeline (5), the ejector (4) is arranged inside the air inlet channel (3) and is externally connected with the air conveying pipeline (5), and the ejector (4) is provided with a plurality of detachable nozzles, so that the upper flow boundary of the air inlet channel is improved, and control of different flow coefficients is realized.
3. 3. The simulation method for the backpack embedded air inlet channel wide-area flow coefficient test according to claim 2, wherein the openings of the nozzles on the ejector (4) are different so as to realize accurate control of the flow coefficient.
4. 4. The backpack embedded type air inlet channel wide-area flow coefficient test simulation method according to claim 1, wherein the total static pressure measuring rake (9) adopts a cross-shaped layout, takes a cross-shaped intersection point as an origin, and a plurality of total pressure and static pressure measuring points are distributed in the extending direction of the cross so as to obtain pressure distribution at an outlet of the air inlet channel.
5. 5. The method for simulating a backpack embedded air inlet wide-area flow coefficient test according to claim 4, wherein the flow coefficient is defined as a ratio of a flow actually entering the air inlet to a reference flow of the air inlet, and is as follows: In the formula, As a flow coefficient of the water, the water is mixed with water, For the actual air flow into the inlet duct, the unit is kg/s, And the reference flow is the inlet channel.
6. 6. The backpack embedded air inlet wide-area flow coefficient test simulation method according to claim 5, wherein the air inlet reference flow Obtained by calculation of the following formula, Wherein, the Represents the total pressure of the incoming flow, T 0 represents the total temperature of the incoming flow, Representing the incoming flow velocity coefficient, a i representing the inlet capture area of the inlet, m representing a constant, Is a flow function of far field incoming flow.
7. 7. The backpack embedded air inlet duct wide-area flow coefficient test simulation method according to claim 5, wherein the flow actually entering the air inlet duct is And calculating by adopting the total pressure measurement value of the outlet of the air inlet channel.
8. 8. The method for simulating a backpack embedded air inlet wide-area flow coefficient test according to claim 7, wherein the flow actually entering the air inlet is In the calculation process, the air inlet channel is taken as a whole, and the actual flow expression passing through the section of the air inlet channel can be obtained as follows: Wherein, the Represents the average total pressure outlet of the outlet section of the air inlet channel, To load the pressure and drag out the cross-sectional area of the inlet channel, T 0 represents the total incoming flow temperature and m represents a constant as a function of the average flow rate of the outlet section of the air inlet channel.
9. 9. The method for simulating a backpack embedded air inlet wide-area flow coefficient test according to claim 8, wherein the average total outlet of the outlet cross section of the air inlet is The total pressure data on the pressure measuring harrow at the outlet of the air inlet channel is calculated by adopting a flow averaging method.

Description

Backpack embedded type air inlet channel wide-area flow coefficient test simulation method Technical Field The application belongs to an air inlet channel wind tunnel test method, and particularly relates to a backpack embedded type air inlet channel wide-area flow coefficient test simulation method. Background With the continuous development of aircraft design technology, the requirements on the performance of the air inlet channel are also continuously improved. Particularly, under complex flight conditions, such as transonic speed, large attack angle and other flight conditions, the flow characteristics of the air inlet channel can be influenced by various factors, such as flow separation, shock wave interference, internal and external flow interaction and other problems. In order to accurately simulate the performance of the air inlet channel under the complex working conditions, a test method capable of covering a wide-range flow coefficient range is required. The existing design method of the air inlet of the aircraft with the flying wing layout generally adopts a backpack embedded air inlet, compared with the air inlet of the belly of the aircraft body, the layout can effectively reduce the infrared scattering source, but the problem of coupling of internal and external flows is commonly existed, specifically, under the suction effect of the air inlet, the external flow structures such as front edge vortex and the like are easily sucked into the air inlet to cause the air inlet uniformity to be easily influenced, and the performance of an engine is further influenced. The overflow and suction effects of the air inlet channel can influence the external flow structure, and further influence the aerodynamic characteristics. At present, the research on the air inlet and outlet effects of an air inlet channel is generally carried out only on a single air inlet channel to simulate the flow coefficient, and the influence of external flow of a machine body is rarely considered. Therefore, in order to master the internal and external flow coupling characteristics of the cloth, the invention discloses a wide-domain flow coefficient test simulation method aiming at the air inlet channel of the all-aircraft flying wing configuration aircraft. Disclosure of Invention The application aims to overcome the problems in the prior art, and discloses a backpack embedded type air inlet channel wide-area flow coefficient test simulation method, which realizes accurate control and comprehensive measurement of an internal flow field of an air inlet channel. The aim of the application is achieved by the following technical scheme: A backpack embedded type air inlet channel wide-area flow coefficient test simulation method comprises the following steps: When the upper boundary control is carried out on the flow of the air inlet, the inner flow channel suction device is arranged on the air inlet to realize the effective control of the upper boundary of the flow of the air inlet; the method comprises the steps of setting up a replaceable inlet lip static pressure and dynamic pressure measuring module and a wall static pressure measuring module distributed along the inlet to measure the pressure of the inlet lip bulge, and setting up a total static pressure measuring rake at the tail end of the inlet to calculate the flow coefficient and internal resistance so as to realize quantitative analysis of the performance of the inlet. According to a preferred embodiment, the internal flow channel suction device comprises an ejector and a gas transmission pipeline, wherein the ejector is arranged inside the air inlet channel and is externally connected with the gas transmission pipeline, and the ejector is provided with a plurality of detachable nozzles, so that the upper flow boundary of the air inlet channel is improved, and the control of different flow coefficients is realized. According to a preferred embodiment, the openings of the nozzles on the ejector are different to achieve accurate control of the flow coefficient. According to a preferred embodiment, the total static pressure measuring rake adopts a cross-shaped layout, takes a cross-shaped intersection point as an origin, and distributes a plurality of total pressure and static pressure measuring points in the extending direction of the cross, so as to obtain pressure distribution at the outlet of the air inlet channel. According to a preferred embodiment, the flow coefficient is defined as the ratio of the flow actually entering the intake duct to the intake duct reference flow, and is: In the formula, As a flow coefficient of the water, the water is mixed with water,For the actual air flow into the inlet duct, the unit is kg/s,And the reference flow is the inlet channel. According to a preferred embodiment, the inlet reference flowObtained by calculation of the following formula, Wherein, the Represents the total pressure of the incoming flow, T 0 represents the total tem