CN-121994447-A - Parallel air bridge balance force measuring system and design method thereof

CN121994447ACN 121994447 ACN121994447 ACN 121994447ACN-121994447-A

Abstract

A parallel air bridge balance force measuring system and a design method thereof belong to the technical field of aviation wind tunnel tests. The parallel air bridge balance force measuring system is arranged in a ventilation machine body, the fixed end of an integrated parallel balance is connected with a web support rod, a measuring end is connected with the ventilation machine body, and a middle air inlet channel is connected with the measuring end of the integrated parallel balance. The air bridge fixed end support is connected with the integrated parallel balance fixed end, the air inlet end of the air bridge pipeline is connected with the air bridge fixed end support, and the air outlet end of the air bridge pipeline is connected with the ventilation machine body. A gap is reserved between the air bridge fixed end support and the ventilation machine body. The reinforcing ribs are arranged on the ventilation fuselage, so that the problem of structural design of the wind tunnel model balance caused by insufficient model space and difficulty in arrangement of the air bridge balance system under the condition of special air inlet channels such as the middle air inlet channel of the aircraft is solved, and the applicability and flexibility of the air bridge system are improved.

Inventors

CHEN JINGWEI
LI FUDONG
TAO AIHUA

Assignees

中国航空工业集团公司哈尔滨空气动力研究所

Dates

Publication Date: 20260508
Application Date: 20260407

Claims (9)

1. The parallel air bridge balance force measurement system is characterized by comprising an air ventilation machine body (1), a central air inlet channel (2), an integrated parallel balance (4), an air bridge pipeline (5), an air bridge fixed end support (6) and an abdominal support rod (7), wherein the central air inlet channel (2) is arranged in the middle of the air ventilation machine body (1), the integrated parallel balance (4) is arranged inside the air ventilation machine body (1), the fixed end of the integrated parallel balance (4) is connected with the abdominal support rod (7), the measuring end of the integrated parallel balance (4) is connected with the air ventilation machine body (1), the air bridge fixed end support (6) is connected with the fixed end of the integrated parallel balance (4), the air inlet end of the air bridge pipeline (5) is connected with the air bridge fixed end support (6), and a gap is reserved between the air bridge pipeline (5) and the air ventilation machine body (1).
2. The parallel air bridge balance force measuring system according to claim 1, wherein an upper reinforcing rib (3) and a lower reinforcing rib (8) are arranged on the ventilation machine body (1), and the upper reinforcing rib (3) and the lower reinforcing rib (8) are only connected with the ventilation machine body (1).
3. The parallel air bridge balance force measuring system according to claim 1, wherein the integrated parallel balance (4) is formed by integrally machining two groups of six-component rod balances (401) which are symmetrically arranged, measuring ends of the two groups of six-component rod balances are integrally machined by an integrated measuring structure (402), and fixed ends of the two groups of six-component rod balances are integrally machined by an integrated fixing structure (403).
4. The parallel air bridge balance force measurement system of claim 3, wherein the strain element of each group of six-component bar balance (401) comprises a first rectangular beam (411), a first T-shaped beam (412), a second T-shaped beam (413) and a second rectangular beam (414), and strain gauges and temperature sensitivity compensation plates are adhered to the first rectangular beam (411), the first T-shaped beam (412), the second T-shaped beam (413) and the second rectangular beam (414).
5. A method for designing a parallel air bridge balance force measuring system, which is the parallel air bridge balance force measuring system of claim 4, characterized by comprising the steps of: The method comprises the steps that firstly, an integrated parallel balance (4) adopts a form of two groups of six-component rod balances (401) which are symmetrically arranged, a fixed end interface of the integrated parallel balance (4) is matched with a belly support strut (7), and a measuring end interface of the integrated parallel balance (4) is matched with a ventilation machine body (1); step two, calculating the pipeline parameters of the air bridge, (1) In the middle of The air density is the maximum design pressure of a pipeline, m is the molar mass of air, R is a universal gas constant, and T is the Kelvin temperature; (2) wherein S is the flow area of an air bridge pipeline (5), M is the single-tube mass flow of the air bridge, Is the flow velocity of air in the air bridge pipeline; the air bridge pipeline (5) is a circular pipe, so that: (3) wherein D is the inner diameter of the air bridge pipeline, and pi is the circumference ratio; According to the performance of the air bridge pipeline material, the welding requirement, the self weight of the pipeline, the connecting thickness and the sealing requirement of other parts, the wall thickness t 1 of the pipeline is selected, then the pressure resistance check of the wall thickness of the pipeline is carried out, the actually selected wall thickness t 1 is required to be larger than the pressure resistance minimum wall thickness t, (4) Wherein t is the pressure-resistant minimum wall thickness, D 1 is the pipe outer diameter, wherein D 1 =D+2*t 1 , And (3) allowing stress for pipeline materials, wherein Ej is a welding coefficient, 1 is taken as a seamless steel pipe, and Y is an influence coefficient.
6. Method for designing a parallel air bridge balance force measurement system according to claim 5, characterized in that the method for assembling an integrated parallel balance (4) comprises: Respectively sticking strain gauges and temperature sensitivity compensation plates on a first rectangular beam (411), a first T-shaped beam (412), a second T-shaped beam (413) and a second rectangular beam (414) of each group of six-component rod balance (401) to form a Wheatstone bridge; the strain gauges on a first rectangular beam (411) in the first group of six-component rod balance (401) are in groups of four to form a bridge M1 and a bridge M3, the strain gauges on a second rectangular beam (414) in the first group of six-component rod balance (401) are in groups of four to form a bridge M2 and a bridge M4, and the strain gauges on a first T-shaped beam (412) and a second T-shaped beam (413) are in groups of four to form a bridge M5; The strain gauges on the first rectangular beam (411) in the second group of six-component rod balance (401) are in a group every four to form a bridge M6 and a bridge M7, the strain gauges on the second rectangular beam (414) in the first group of six-component rod balance (401) are in a group every four to form a bridge M8 and a bridge M9, the strain gauges on the first T-shaped beam (412) and the second T-shaped beam (413) are in a group every four to form a bridge M10, and the six-component output result of the integrated parallel balance is obtained through the combined operation of the bridges M1-M10.
7. The method for designing a parallel air bridge balance force measurement system according to claim 5, wherein the calculation formula of the six-component output result is: The calculation formula of the lift DeltaUY is as follows: △UY=△U1+△U6-△U2-△U7 (5) the calculation formula of the pitching moment delta UMz is as follows: △UMz=△U1+△U2+△U6+△U7 (6) the calculation formula of the lateral force is as follows: △UZ=△U4+△U9-△U3-△U8 (7) the roll torque is calculated as: △UMx=△U1+△U2-△U6-△U7 (8) The calculation formula of yaw torque is: △UMy=△U5-△U10 (9) The calculation formula of the resistance is: △UX=△U5+△U10 (10) wherein DeltaU 1 to DeltaU 10 are output signal variation amounts of the bridge M1 to the bridge M10 respectively.
8. The design method of the parallel air bridge balance force measurement system according to claim 5, comprising the calibration structure of the integrated parallel balance (4), and the design method is characterized by comprising a calibration base (9), a special-shaped calibration support rod (10), an air bridge loading beam (11) and a loading beam connecting piece (12), wherein the calibration base (9) is arranged on a static calibration table, one end of the special-shaped calibration support rod (10) is connected with the calibration base (9), the other end of the special-shaped calibration support rod is connected with the fixed end of the integrated parallel balance (4), the loading beam connecting piece (12) is connected with the measuring end of the integrated parallel balance (4), the air bridge loading beam (11) is connected with the loading beam connecting piece (12), and the air inlet end of the air bridge pipeline (5) is connected with the special-shaped calibration support rod (10), and the air outlet end of the air bridge pipeline (5) is connected with the loading beam connecting piece (12).
9. The method for designing a parallel air bridge balance force measuring system according to claim 8, wherein the loading beam connecting piece (12) is radially provided with an installation gap at the connecting position of the loading beam connecting piece and the air bridge pipeline (5) so as to facilitate the insertion connection of the air bridge pipeline (5).

Description

Parallel air bridge balance force measuring system and design method thereof Technical Field The invention relates to a parallel air bridge balance force measuring system and a design method thereof, and belongs to the technical field of aviation wind tunnel tests. Background Wind tunnel testing is an important aerodynamic experimental method for studying the interaction of gas flow with aircraft models to master the aerodynamic properties of aircraft. In a power simulation wind tunnel force test such as a TPS nacelle or an air motor driven propeller, the engine simulation device is driven by high-pressure air, unlike a real engine. To drive the engine simulation device, a dedicated pipeline is required to convey high-pressure air. According to the test technical requirements, the wind tunnel test needs to be provided with a corresponding internal air bridge balance for reducing the influence of inaccurate measurement caused by high-pressure air supply and low-pressure return air on the balance. The difficult problem that power simulation test must solve is that the pipeline can carry high-pressure air, and the influence on balance dynamometry is less and stable again, and simultaneously can also overcome internal force, temperature effect, the flow influence etc. of high-pressure air. The internal air bridge balance is a key technology for solving the problem, is one of key technologies of power simulation test technologies, and is widely applied to the test of TPS nacelle power simulation, air motor driving propeller simulation and the like. The internal air bridge balance can greatly eliminate the influence of high-pressure air flow on the balance precision, and the force measuring function of the wind tunnel balance is normally exerted. The internal air bridge balance has the functions of not only being capable of conducting high-pressure air, but also not affecting the force measuring precision of the balance. The pneumatic load of the model is transmitted to the supporting system through the balance and the air bridge pipeline. The air bridge pipeline can convey high-pressure air, and proper decoupling is needed, so that the whole air supply pipeline has small and stable influence on the force measurement of the balance. The internal air bridge balance system mainly comprises two parts of a balance and an air bridge pipeline. Each air bridge pipe is composed of three interference eliminating units and a plurality of special-shaped metal round pipes, and the three interference eliminating units are respectively arranged in two directions perpendicular to each other, so that the interference eliminating capability of six degrees of freedom of each air bridge pipe is ensured, and meanwhile the force measuring influence of the air bridge on a balance is reduced. Under normal conditions, the internal air bridge balance system is an integral independent system, and the balance and the air bridge pipeline together perform balance calibration, wind tunnel test and other works, and are not generally detached for use. When the wind tunnel test model is designed, corresponding supporting pieces, air supply pipelines and other parts are required to be designed for being matched with the air bridge balance. The model requires the placement of air bridges, balances, etc. within the fuselage where space is limited. However, in some aircraft configurations, an air inlet is arranged in the middle of the aircraft body, and in the aircraft model with the middle air inlet layout, in the wind tunnel test with power, since the middle of the aircraft body of the model is occupied by a ventilation air inlet, an internal air bridge balance system cannot be normally arranged, so that the wind tunnel test cannot be successfully developed. Therefore, it is needed to provide a parallel air bridge balance force measuring system and a design method thereof to solve the above technical problems. Disclosure of Invention The present invention was developed to solve the structural design difficulty of wind tunnel model scales due to the difficulty in arranging an air bridge scale system under the condition of an air intake duct in the middle of an aircraft, and a brief overview of the present invention is given below in order to provide a basic understanding of some aspects of the present invention. It should be understood that this summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The technical scheme of the invention is as follows: The scheme I comprises a ventilation machine body, a central air inlet channel, an integrated parallel balance, an air bridge fixed end support and an abdomen support supporting rod, wherein the central air inlet channel is arranged in the middle of the ventilation machine body, the integrated parallel balance is arranged in the ventilation machine body, the fixed end of the integrated