A pipeline-integrated six-component jet flow balance and a method of using the same

Abstract

This invention provides a pipe-integrated six-component jet balance and its usage method. The jet balance features an integrally formed axial force element, a five-component element, and a support rod connector, coaxially arranged along the negative X-axis. A pipe runs through the entire balance axis, and the five-component element and support rod connector are equipped with grooves. The axial force element adopts a spoke-type structure, consisting of a moving ring, a stationary ring, and transverse and vertical sensitive beams. The five-component element comprises front and rear rectangular beams and a central cylindrical beam. The support rod connector features a conical inner cone and wedge holes. Strain gauges are mounted on both the axial force element and the five-component element to form a Wheatstone bridge, enabling independent measurement of the six components. This invention integrates the pipe into the balance body, completely avoiding interference from contact between the pipe and the sensitive element, significantly improving force measurement accuracy. The overall structure is compact, with a small diameter and light weight, facilitating calibration and installation. Its usage method is simple to install, provides stable signal output, and can efficiently complete wind tunnel jet force measurement tests.

Description

Technical Field

[0001] This invention relates to the field of aerodynamic testing technology, and in particular to a pipeline-integrated six-component jet balance and its usage method. Background Technology

[0002] Modern aircraft often incorporate jet propulsion systems, which typically eject gas or liquid media carried within the aircraft along its outer surface at a certain pressure. This serves purposes such as heat reduction, drag reduction, and aerodynamic control. Jet propulsion force measurement tests simulate the jet propulsion state of an aircraft in a ground-based wind tunnel, using a jet propulsion balance to measure the aerodynamic forces and torques acting on the jet-propelled aircraft.

[0003] During jet flow tests, the high-pressure airflow typically enters from the tail end of the support rod, flows through the rod into the model, passes through the balance into the stagnation chamber, and then exits from the nozzle. This means that the air pipe delivering the high-pressure airflow needs to run along the balance's axis. To meet this requirement, most currently used jet flow balances have open through-holes along the balance's axis, and the sensitive elements of the balance are distributed in a ring on the balance. This type of jet flow balance is widely used in jet flow force measurement tests.

[0004] However, due to the presence of the air intake pipe, when the pipe is filled with air, the taut pipe wall may come into contact with the inner wall of the jet balance or directly interfere with the sensitive element, thus affecting the force measurement results. Simultaneously, when the model changes its angle of attack, the weight of the pipe itself will also affect the force measurement results to varying degrees. To avoid interference from the pipe, a common practice is to increase the diameter of the through-hole in the balance. This further increases the overall diameter of the balance, leading to increased difficulty in balance calibration and jet model design, and this method cannot completely eliminate pipe interference. This situation, to some extent, restricts the accuracy and efficiency of jet force measurement experiments. Currently, there is an urgent need to develop a jet balance configuration that can effectively control pipe interference. Summary of the Invention

[0005] The purpose of this invention is to provide a pipeline-integrated six-component jet balance and its usage method, which integrates the air intake pipeline into the balance body structure, avoids direct contact between the pipeline and the sensitive element, significantly improves the force measurement accuracy, and at the same time reduces the balance diameter and mass, and reduces the difficulty of calibration and installation.

[0006] According to one objective of the present invention, an integrated six-component jet balance is provided, comprising an axial force element, a five-component element, and a support rod connector arranged coaxially along the negative X-axis. The axial force element, the five-component element, and the support rod connector are integrally formed. A gas pipe is provided along the X-axis through the entire balance axis. Grooves are evenly distributed on the five-component element and the support rod connector. The axial force element includes a moving ring and a stationary ring, with a transverse sensitive beam and a vertical sensitive beam connecting the moving ring and the stationary ring. The five-component element includes a front rectangular beam, a rear rectangular beam, and a central cylindrical beam. The support rod connector has a conical inner cone and a wedge hole. Strain gauges are mounted on both the axial force element and the five-component element.

[0007] Furthermore, the outer ring of the moving ring is an outer conical mating surface coaxial with the balance, and the front end face of the moving ring is provided with four screw holes distributed along the circumference.

[0008] Furthermore, the transverse sensitive beams are distributed along the Z-axis, the vertical sensitive beams are distributed along the Y-axis, and multiple sets of the transverse and vertical sensitive beams are arranged sequentially along the X-axis between the outer ring of the moving ring and the inner ring of the stationary ring.

[0009] Furthermore, the thickness of the transverse sensitive beam is less than the thickness of the vertical sensitive beam.

[0010] Furthermore, strain gauges are attached to the roots of the transverse sensitive beam and the vertical sensitive beam near the outer ring, and the strain gauges form a Wheatstone bridge for measuring the axial force X.

[0011] Furthermore, the front rectangular beam and the rear rectangular beam are symmetrically arranged on the front and rear sides of the cylindrical beam. Both of them have rectangular cross sections and are fitted with strain gauges. The strain gauges respectively form a Wheatstone bridge for measuring the normal force Y, lateral force Z, pitching moment Mz, yaw moment My, and roll moment Mx.

[0012] Furthermore, the inner cone of the support rod connector is coaxial with the balance axis, and the wedge hole is higher than the balance axis and parallel to the Z-axis.

[0013] Furthermore, the air pipe is provided with a front internal thread and a rear internal thread at both ends, and the grooves are arranged in a cross shape in the circumferential direction of the five-component element and the support rod connector, and the cross section is rectangular.

[0014] According to another objective of the present invention, the present invention provides a method for using the above-mentioned pipeline integrated six-component jet balance, comprising: connecting the rear air inlet pipe to the air pipe via the rear internal thread; engaging the inner cone of the support rod connector with the outer cone of the support rod and securing it by wedging through the wedge hole; positioning the model with the outer conical mating surface of the moving ring and locking it through the screw hole; connecting the front jet pipe to the air pipe via the front internal thread; and introducing the balance lead wire into the support rod through the wire groove.

[0015] Furthermore, during the test, the aerodynamic load is transmitted to the axial force element and the five-component element via the dynamic ring. The strain gauge bridge of the axial force element outputs the axial force signal, and the strain gauge bridge of the five-component element independently outputs the normal force, lateral force, pitching moment, yaw moment and roll moment signals, realizing six-component force measurement without pipeline interference.

[0016] The technical solution of this invention significantly improves the overall rigidity and structural stability of the balance by using a coaxially integrated axial force element, a five-component element, and a support rod connector, thus avoiding the impact of assembly errors on measurement accuracy. Integrating the air tube into the balance's axis and running through the entire structure eliminates the need for additional large-diameter through holes, effectively reducing the balance's diameter and weight, and simplifying calibration and model design. The built-in air tube design isolates the sensitive element from interference caused by air-filled deformation and its own weight, significantly improving force measurement accuracy. A dedicated wire channel layout ensures neat and protected lead wire storage. The spoke-type axial force element and the rectangular beam-type five-component element, combined with a strain gauge, can accurately and independently measure six-component signals, balancing high sensitivity and high anti-interference capability, comprehensively improving the accuracy and efficiency of jet force measurement experiments. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 This is a front view of an embodiment of the present invention; Figure 3 This is an embodiment of the present invention. Figure 2 A sectional view along the middle AA; Figure 4 This is an embodiment of the present invention. Figure 3 A sectional view along the middle edge BB; Figure 5 This is a schematic diagram showing the bonding position of the strain gauge in the axial force element according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the assembly of the Wheatstone bridge in the axial force element of an embodiment of the present invention.

[0019] In the diagram: 1. Axial force element; 101. Moving ring; 1011. Outer ring; 1012. Screw hole; 102. Stationary ring; 1021. Transverse sensitive beam; 1022. Vertical sensitive beam; 1023. Inner ring; 2. Five-component element; 201. Front rectangular beam; 202. Rear rectangular beam; 203. Cylindrical beam; 3. Support rod connector; 301. Wedge hole; 302. Internal cone; 4. Air pipe; 401. Front internal thread; 402. Rear internal thread; 5. Wire groove; 6. Strain gauge. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Example 1 like Figures 1-6As shown, a pipeline integrated six-component jet balance includes an axial force element 1, a five-component element 2, and a support rod connector 3 arranged sequentially along the negative X-axis. An air pipe 4 is located at the axis of the balance and runs through the entire balance along the X-axis. The five-component element 2 and the support rod connector 3 are provided with wire grooves 5. All of the above components are integrally formed.

[0024] Specifically, such as Figure 2 As shown, the axial force element 1 includes a moving ring 101 and a stationary ring 102. The moving ring 101 is fixed to the model, and the moving ring 101 and the stationary ring 102 are connected by a series of transverse sensitive beams 1021 and vertical sensitive beams 1022.

[0025] like Figure 3 As shown, the five-component element 2 consists of a front rectangular beam 201, a rear rectangular beam 202, and a central cylindrical beam 203.

[0026] The support rod connector 3 has an inner cone 302 inside, which is a conical mating surface and has two wedge holes 301.

[0027] Trachea 4 is located at the center of the balance and runs through the entire balance along the X-axis.

[0028] Strain gauges 6 are attached to both the axial force element 1 and the five-component element 2.

[0029] The outer ring 1011 on the moving ring 101 is an outer conical mating surface and is coaxial with the balance axis. The front end face of the moving ring 101 is provided with four screw holes 1012, which are distributed in an "X" shape in the circumferential direction.

[0030] The transverse sensitive beam 1021 and the vertical sensitive beam 1022 are located between the outer ring 1011 and the inner ring 1023. The transverse sensitive beam 1021 is distributed along the Z-axis, and multiple transverse sensitive beams are arranged sequentially along the X-axis. The vertical sensitive beam 1022 is distributed along the Y-axis, and multiple vertical sensitive beams are arranged sequentially along the X-axis.

[0031] The thickness of each transverse sensitive beam 1021 is less than that of the vertical sensitive beam 1022.

[0032] Strain gauges 6 are attached to the outermost roots of the transverse sensitive beam 1021 and the vertical sensitive beam 1022, near the outer ring 1011. The strain gauges 6 are connected to form a Wheatstone bridge for measuring the axial force X.

[0033] The five-component element 2 is located behind the axial force element 1 and is coaxial with the axial force element 1. The front rectangular beam 201 and the rear rectangular beam 202 are arranged along the X-axis on the front and rear sides of the cylindrical beam 203, respectively.

[0034] Both the front rectangular beam 201 and the rear rectangular beam 202 have rectangular cross-sectional shapes, and strain gauges 6 are attached to both the front rectangular beam 201 and the rear rectangular beam 202. The strain gauges 6 are connected to form a Wheatstone bridge for measuring the normal force Y, the lateral force Z, the pitching moment Mz, the yaw moment My, and the roll moment Mx.

[0035] The support rod connector 3 is located behind the five-component element 2 and is coaxial with the cylindrical beam 203. The inner cone 302 is coaxial with the balance axis. The wedge hole 301 is higher than the balance axis by a certain distance and is parallel to the Z-axis.

[0036] The trachea 4 is coaxial with the balance axis and runs through the entire balance. The front internal thread 401 and the rear internal thread 402 are located at the front and rear ends of the trachea 4, respectively.

[0037] The cable grooves 5 are distributed on the five-component element 2 and the support rod connector 3, and are arranged in a cross shape around the circumference of the balance. The cross-sectional shape of the cable grooves 5 is rectangular.

[0038] This invention relates to a pipeline-integrated six-component jet balance, which integrates the jet pipeline as part of the balance within the balance axis. It also uses spoke-type axial force elements and rectangular beam-type five-component elements to isolate the direct contact between the sensitive elements and the pipeline, effectively reducing the influence of the pipeline on the force measurement results of the balance and further improving the accuracy of jet force measurement tests.

[0039] Compared with existing jet balances, the pipe-integrated six-component jet balance of the present invention does not require additional installation space for the pipes at the balance axis, resulting in a smaller overall diameter and mass, which facilitates installation during calibration and testing.

[0040] Example 2 like Figures 1-6 As shown, a pipeline-integrated six-component jet balance includes an axial force element 1, a five-component element 2, a support rod connector 3, an air pipe 4, a cable groove 5, and a strain gauge 6, wherein: The axial force element 1 is located at the front end of the balance and is a spoke-type structure composed of a moving ring 101 and a stationary ring 102. The moving ring 101 is located on the outer side, and the outer surface of the outer ring 1011 is a conical surface. In this embodiment, the taper of the conical surface is 1:10. Four screw holes 1012 are provided at the small conical end face of the moving ring. The screw holes are distributed in an "X" pattern in the circumferential direction. This is to maximize the distance between the screw holes and the axial force element sensitive beam to prevent the screw preload from interfering with the output of the axial force element. The balance as a whole is coaxially positioned by the outer conical surface of the outer ring 1011 engaging with the inner conical surface of the same size at the corresponding position of the jet model, and is tightened to the model through the screw holes 1012, effectively ensuring the positioning accuracy between the balance and the model. The inner ring 1023 of the stationary ring 102 is located inside the moving ring 101. Its shape is cylindrical, and it is connected to the outer ring 1011 through a series of transverse sensitive beams 1021 and vertical sensitive beams 1022. The transverse sensitive beams 1021 and vertical sensitive beams 1022 are arranged in a cross shape within the balance, with the transverse sensitive beams 1021 distributed along the Z-axis and the vertical sensitive beams 1022 distributed along the Y-axis. Multiple sensitive beams in each direction are arranged along the X-axis. In this embodiment, there are 5 transverse and 5 vertical sensitive beams along the Y and Z axes, totaling 20 beams. In general jet flow tests, the normal force / moment of the model is usually greater than the lateral force / moment; therefore, in this embodiment, the thickness of each vertical sensitive beam 1022 is greater than the thickness of each transverse sensitive beam 1021. Strain gauges 6 are attached to the outermost transverse sensitive beams 1021 and vertical sensitive beams 1022 near the root of the outer ring 1011, totaling 8 gauges. Figure 5 As shown. These strain gauges 6 are connected to form a Wheatstone bridge for measuring the axial force X, as... Figure 6 As shown. The specific mounting position of the strain gauge 6 on the axial force element 1 and the construction of the Wheatstone bridge are well-known techniques to those skilled in the art and will not be described in detail here.

[0041] The five-component element 2 is located behind and coaxial with the axial force element 1, and consists of a central cylindrical beam 203, a front rectangular beam 201, and a rear rectangular beam 202. The front rectangular beam 201 and the rear rectangular beam 202 are distributed along the X-axis on the front and rear sides of the cylindrical beam 203, respectively. In this embodiment, both rectangular beams have rectangular cross-sections with the same shape and length. Considering that in general jet flow tests, the normal force / moment of the model is generally greater than the lateral force / moment, in this embodiment, the width of the rectangular beam in the Y-direction is greater than its width in the Z-direction. Figure 4As shown. Several strain gauges 6 are attached to the outer surfaces of both the front rectangular beam 201 and the rear rectangular beam 202. These strain gauges 6 are connected to form a Wheatstone bridge for measuring the normal force Y, lateral force Z, pitching moment Mz, yaw moment My, and roll moment Mx. The specific attachment positions of the strain gauges 6 on the five-component element 2 and the construction of the Wheatstone bridge are well-known techniques to those skilled in the art and will not be elaborated further. Four grooves 5 are formed on the surface of the cylindrical beam 203, arranged in a cross shape along the circumference of the balance, and the cross-sectional shape of the grooves 5 is rectangular. The grooves 5 on the cylindrical beam 203 are used to guide the leads from the axial force element 1 and the front rectangular beam 201 to the grooves 5 on the support rod connector 3.

[0042] The support rod connector 3 is cylindrical, located behind and coaxial with the five-component element 2. Its inner side is an inner cone 302, coaxial with the balance axis. The appropriate size of the inner cone 302 can be determined based on the size of the front cone of the support rod; in this embodiment, the taper of the inner cone 302 is 1:10. The wedge hole 301 is a certain distance above the balance axis and parallel to the Z-axis. The balance is coaxially positioned with the outer cone of the front section of the support rod via the inner cone 302, and is tightened and fixed by a wedge passing through the wedge hole 301. Four grooves 5 are formed on the surface of the support rod connector 3, distributed in a cross shape around the circumference of the balance, and the cross-sectional shape of the grooves 5 is rectangular, used to guide all the leads on the balance to the tail of the balance.

[0043] The air pipe 4 runs through the entire balance along the X-axis. The cross-sectional shape of the air pipe 4 is circular, and its diameter can be adjusted according to the air volume. The two ends of the air pipe 4 are respectively machined with a front internal thread 401 and a rear internal thread 402, which are used to connect the front and rear jet pipes. The rear internal thread 402 is used to connect to the air inlet pipe, and the air pipe connected to the front internal thread 401 is connected to the model injection chamber or directly to the jet hole on the model surface.

[0044] Working principle: The pipeline-integrated six-component jet balance of the present invention, when performing jet force measurement tests: First, connect the jet air intake pipe to the rear internal thread 402. Then, mate the inner cone 302 of the support rod connector 3 with the front cone of the support rod, and use a wedge to pass through the wedge hole to tighten and fix the balance to the support rod. Then connect the front jet pipe of the injection chamber or the jet hole on the model surface to the front internal thread 401, and at the same time mate the inner conical surface of the model with the outer conical surface of the outer ring 1011 of the moving ring, and tighten and fix it through the screw hole 1012; Finally, the balance lead wire is introduced into the support rod through the wire groove 5. After the installation is completed, the test can be carried out.

[0045] The aerodynamic load acting on the model is transmitted to the axial force element 1 and the five-component element 2 through the dynamic ring 101. Under the action of the aerodynamic load, the Wheatstone bridge composed of strain gauges 6 arranged on the transverse sensitive beam 1021 and the vertical sensitive beam 1022 only produces output under the action of the axial force X. Under the action of the aerodynamic load, the five Wheatstone bridges composed of strain gauges 6 arranged at different positions on the five-component element 2 only produce output under the action of the normal force Y, the lateral force Z, the pitching moment Mz, the yaw moment My, and the roll moment Mx, respectively.

[0046] This six-component jet balance effectively isolates the direct interference of the jet pipeline to each sensitive element of the balance, further improving the accuracy of jet force measurement tests. At the same time, it has high integration and low manufacturing difficulty. The overall diameter and mass of the balance are smaller than those of conventional jet balances, making it easier to install during calibration and testing.

[0047] This invention integrates the jet pipe into the balance axis, isolating the pipe from contact with the sensitive element and eliminating pipe interference; it adopts a spoke-type axial force element and a rectangular beam-type five-component element, resulting in high measurement accuracy and good structural rigidity; it eliminates the need for extra pipe space, resulting in a smaller balance diameter and mass, which facilitates calibration, installation and model adaptation.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pipeline-integrated six-component jet balance, characterized in that, The balance includes an axial force element, a five-component element, and a support rod connector arranged coaxially along the negative X-axis. The axial force element, the five-component element, and the support rod connector are integrally formed. A gas tube runs through the entire balance along the X-axis at its axis. Grooves are evenly distributed on the five-component element and the support rod connector. The axial force element includes a moving ring and a stationary ring, connected by a transverse sensitive beam and a vertical sensitive beam. The five-component element includes a front rectangular beam, a rear rectangular beam, and a central cylindrical beam. The support rod connector has a conical inner cone and a wedge hole. Strain gauges are mounted on both the axial force element and the five-component element.

2. The pipeline-integrated six-component jet balance according to claim 1, characterized in that, The outer ring of the moving ring is a conical mating surface coaxial with the balance, and the front end face of the moving ring is provided with four screw holes distributed along the circumference.

3. The pipeline-integrated six-component jet balance according to claim 1, characterized in that, The transverse sensitive beams are distributed along the Z-axis, and the vertical sensitive beams are distributed along the Y-axis. Multiple sets of the transverse and vertical sensitive beams are arranged sequentially along the X-axis between the outer ring of the moving ring and the inner ring of the stationary ring.

4. The pipeline-integrated six-component jet balance according to claim 3, characterized in that, The thickness of the transverse sensitive beam is less than the thickness of the vertical sensitive beam.

5. The pipeline-integrated six-component jet balance according to claim 3, characterized in that, The strain gauges are attached to the roots of the transverse sensitive beam and the vertical sensitive beam near the outer ring, and the strain gauges form a Wheatstone bridge for measuring the axial force X.

6. The pipeline-integrated six-component jet balance according to claim 1, characterized in that, The front rectangular beam and the rear rectangular beam are symmetrically arranged on the front and rear sides of the cylindrical beam. Both beams have rectangular cross sections and are fitted with strain gauges. The strain gauges form a Wheatstone bridge to measure the normal force Y, lateral force Z, pitching moment Mz, yaw moment My, and roll moment Mx.

7. The pipeline-integrated six-component jet balance according to claim 1, characterized in that, The inner cone of the support rod connector is coaxial with the axis of the balance, and the wedge hole is higher than the axis of the balance and parallel to the Z-axis.

8. The pipeline-integrated six-component jet balance according to claim 1, characterized in that, The air pipe is provided with a front internal thread and a rear internal thread at both ends, and the groove is arranged in a cross shape in the circumferential direction of the five-component element and the support rod connector and has a rectangular cross section.

9. The method of using the pipeline integrated six-component jet balance according to any one of claims 1-8, characterized in that, include: Connect the rear air intake pipe to the rear internal thread of the air pipe, mate the inner cone of the support rod connector with the outer cone of the support rod and wedge it tightly through the wedge hole; position the model and the outer conical mating surface of the moving ring and lock it through the screw hole; connect the front jet pipe to the front internal thread of the air pipe, and introduce the balance lead into the inside of the support rod through the wire groove.

10. The method of using the pipeline-integrated six-component jet balance according to claim 9, characterized in that, During the test, the aerodynamic load is transmitted to the axial force element and the five-component element through the dynamic ring. The strain gauge bridge of the axial force element outputs the axial force signal, and the strain gauge bridge of the five-component element independently outputs the normal force, lateral force, pitching moment, yaw moment and roll moment signals, realizing six-component force measurement without pipeline interference.

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