Test System and Method Integrating Structural Adjustment and Performance Measurement of High-Speed Inlet

Abstract

An experimental system and method for integrating the adjustment and performance measurement of a high-speed inlet structure, comprising: a hollow center cone, a hollow contraction shroud, a measurement section connected to the shroud and the center cone, a fixed cylinder connected to the measurement section and the center cone, a motor drive system connected to the fixed cylinder, a lead screw pair connected to the drive system and the center cone, and a displacement sensor connected to the fixed cylinder and the lead screw pair; the outer surface of the center cone and the inner cavity of the shroud enclose an inlet passage; the center cone can achieve controllable axial linear movement by the mechanism composed of the fixed cylinder, the motor drive system, and the lead screw pair; the measurement section includes an outer cylinder, an inner cylinder, and a hollow support plate for connecting the outer cylinder and the inner cylinder; a plurality of pitot tubes are installed on the hollow support plate, and a plurality of static pressure tubes are installed on both the outer cylinder and the inner cylinder. The pitot pressure measured by the pitot tubes and the wall static pressure measured by the static pressure tubes are used to determine the performance parameters of the main passage.

Description

Technical Field

[0001] The present invention relates to an experimental system and method for integrating the structural adjustment and performance measurement of a high-speed inlet, that is, a wind tunnel experimental system and method for integrating the structural adjustment and performance measurement of a hypersonic inlet, belonging to the field of wind tunnel experiments. Background Technique

[0002] As an inlet device for scramjet engines and their combined power, the hypersonic inlet is responsible for providing air that meets the combustion requirements for the engine. The quality of the inlet performance is crucial for the engine, just like the importance of the respiratory system to a person. To ensure the efficient and stable operation of the engine within a wide range, the structure of the inlet needs to be dynamically adjusted so that the inlet is always in an optimal working state in real time, in order to broaden the working boundary of the engine and avoid situations such as insufficient thrust or even non-start (similar to altitude sickness in humans). This requires the establishment of a high-speed adjustable inlet test system and measurement method.

[0003] In the prior art, the hypersonic adjustable inlet wind tunnel test has not addressed the problem of interference between the bleed air flow of the inlet and the structural adjustment drive mechanism, and there is a lack of real-time monitoring means with high reliability and high precision for the position during the structural adjustment process of the inlet. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art and solve the problems of inlet bleed air flow and structural adjustment, as well as the corresponding measurement problems.

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] A wind tunnel test system for integrating the structural adjustment and performance measurement of a hypersonic inlet, comprising:

[0007] A hollow central cone, a hollow convergent outer shroud, a measurement section connected to the outer shroud and the central cone, a fixed cylinder connected to the measurement section and the central cone, a motor drive system connected to the fixed cylinder, a lead screw pair connected to the drive system and the central cone, and a displacement sensor connected to the fixed cylinder and the lead screw pair; the outer surface of the central cone and the inner cavity of the outer shroud enclose an inlet passage;

[0008] The central cone can achieve controllable axial linear motion by the mechanism composed of the fixed cylinder, the motor drive system, and the lead screw pair, so as to adjust the minimum cross-sectional area of the main passage of the inlet passage;

[0009] The measurement section includes an outer cylinder, an inner cylinder, and a hollow support plate for connecting the outer cylinder and the inner cylinder; a plurality of pitot tubes are installed on the hollow support plate, and a plurality of static pressure tubes are installed on both the outer cylinder and the inner cylinder. The pitot pressure measured by the pitot tubes and the wall static pressure measured by the static pressure tubes are used to determine the performance parameters of the main passage.

[0010] Preferably, the motor drive system is a programmable controlled DC servo motor system with a reducer.

[0011] Preferably, the lead screw pair includes a slider and a lead screw, and is used to convert the rotational motion of the motor drive system into the linear motion of the slider.

[0012] Preferably, the displacement sensor is a magnetoresistive displacement sensor composed of a magnetic ring and a guide rod scale.

[0013] Preferably, the real-time position of the center cone is given by the position of the magnetic ring of the displacement sensor on the guide rod scale of the displacement sensor, where the center cone, the slider of the lead screw pair and the magnetic ring of the displacement sensor are fixedly connected.

[0014] Preferably, the performance parameters of the main channel include one or more of the total outlet pressure, Mach number, and flow rate.

[0015] Preferably, the intake channel includes a bleed channel and a main channel; the bleed channel is a flow path surrounded by the bleed holes or slots on the center cone, the hollow cavity of the center cone, the bleed slots arranged in a staggered manner on the front and rear of the barrel wall of the fixed cylinder and the hollow cavity of the fixed cylinder, and the hollow slots of the struts on the measurement section.

[0016] Preferably, the gas flowing out of the bleed holes or slots on the center cone is discharged through the hollow slots of the hollow struts; the bleed channel exhibits a double-throat characteristic; the first throat of the intake bleed channel is the bleed hole or slot; the second throat of the intake bleed channel is the minimum cross-sectional area at other downstream parts; the area of the second throat of the intake bleed channel is not less than 2 times the area of the first throat of the intake bleed channel.

[0017] Preferably, the main channel of the intake is a connected flow path surrounded by the center cone housing, the inner wall of the outer cover, the outer cylinder, and the inner cylinder, and exhibits a double-throat characteristic. The first throat of the main channel of the intake is the minimum flow cross-section surrounded by the center cone housing and the inner wall of the outer cover. The second throat of the main channel of the intake is the flow cross-section surrounded by the outer cylinder, the inner cylinder, and the hollow struts. The area of the second throat of the main channel of the intake is not less than 2.5 times the area of the first throat of the main channel of the intake.

[0018] Preferably, the center cone and the fixed cylinder are connected by a graphite copper sleeve, which is used to reduce the frictional resistance and for gas sealing of the main channel of the intake during the adjustment process of the intake structure.

[0019] Preferably, the motor drive system is completely placed inside the inner cylinder.

[0020] A wind tunnel test method for integrating the structural adjustment and performance measurement of a hypersonic inlet, using the above test system, includes:

[0021] Adjust the minimum cross-sectional area of the main channel of the inlet channel;

[0022] During the structural adjustment of the inlet, the Mach number, total pressure recovery coefficient, and flow coefficient at the outlet of the main channel are determined as follows:

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] In the above formula, the subscript i represents the radial number of the pitot tube on the strut of each measurement section. There are a total of I pitot tubes, numbered (1,..., I) from the inside out; the subscript j represents the number of the strut of the measurement section. There are a total of J struts, numbered (1,..., J) counterclockwise from the bottom; γ is the specific heat ratio of the test gas, taken as 1.4; σ is the total pressure recovery coefficient; φ is the inlet flow capture coefficient; Ma1 is the average Mach number of the inlet outlet flow; p t,1 is the average total pressure of the inlet outlet flow; p t,2,i,j , Ma i,j , p t,1,i,j are the pitot pressure, Mach number, and total pressure measured by the i-th pitot tube on the j-th strut of the measurement section respectively; p1 is the arithmetic mean of all wall static pressures; p 1,内壁,j , p1, outer wall ,j are the static pressures on the inner wall and outer wall corresponding to the j-th strut of the measurement section; p t,∞ , Ma ∞ are the total pressure and Mach number of the test incoming flow respectively, given by the test; A ∞ is the ideal capture area of the inlet, given by the test; A1 is the area of the main channel of the measurement section; q(Ma ∞ ), q(Ma i,j ) are flow functions obtained from the aerodynamics textbook according to Ma ∞ , Ma i,j .

[0032] The present invention has the following beneficial effects compared with the prior art:

[0033] (1) The test system provided by the present invention is equipped with an inlet duct bleed flow passage and a motion mechanism for adjusting the inlet duct structure, which not only meets the air flow discharge requirements of the inlet duct bleed passage, but also realizes the function of adjusting the inlet duct structure;

[0034] (2) The test system provided by the present invention is equipped with a measurement section, which has the functions of measuring the performance parameters of the inlet duct, such as the total pressure at the outlet, Mach number, flow rate, etc., and can dynamically give the performance changes of the inlet duct during the structure adjustment process;

[0035] (3) The test system provided by the present invention is equipped with high-reliability, high-precision and high-displacement sensors, which can give the motion displacement of the inlet duct structure in real time, and form mutual verification with the feedback data of the programmed control DC servo motor. On the one hand, it realizes the real-time monitoring of the inlet duct structure adjustment process, and on the other hand, it realizes the one-to-one correspondence between the structure position and the inlet duct performance parameters;

[0036] (4) The high-speed inlet duct wind tunnel test system provided by the present invention is equipped with graphite copper sleeves between the moving parts and the fixed parts, which not only reduces the friction resistance of the moving parts, but also meets the gas sealing requirements of the main channel during the adjustment process of the air duct structure;

[0037] (5) The test system provided by the present invention places the motor drive mechanism for adjusting the inlet duct structure completely inside the center cone, solving the problem of motor overheating faced in the wind tunnel test of the inlet duct with a Mach number above 5. Description of the Drawings

[0038] Figure 1 is a schematic diagram of the composition of the test system of the present invention;

[0039] Figure 2 is a schematic diagram of the arrangement of the pitot tubes and the measurement point numbers in the measurement section of the test system of the present invention;

[0040] Figure 3 is a schematic diagram of parameters such as the Mach number Ma, total pressure recovery coefficient σ, and flow coefficient φ at the outlet of the main channel of the inlet duct during the structure adjustment process measured by using the test system and method of the present invention. Detailed Embodiments

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in detail with reference to the drawings.

[0042] A wind tunnel test system integrating the structure adjustment and performance measurement of a hypersonic inlet duct, as Figure 1 shown, includes:

[0043] Hollow central cone 1, hollow shrinkage outer cover 2, measuring section 3 connected to the outer cover 2 and the central cone 1, fixed cylinder 4 connected to the measuring section 3 and the central cone 1, motor drive system 5 connected to the fixed cylinder 4, lead screw pair 6 connected to the drive system 5 and the central cone 1, displacement sensor 7 connected to the fixed cylinder 4 and the lead screw pair 6; an air inlet passage 8 is formed between the outer surface of the central cone 1 and the inner cavity of the outer cover 2;

[0044] The central cone 1 can achieve controllable axial linear motion by the mechanism composed of the fixed cylinder 4, the motor drive system 5, and the lead screw pair 6, so as to adjust the minimum cross-sectional area of the main passage 82 of the air inlet passage 8;

[0045] The measuring section 3 includes an outer cylinder 31, an inner cylinder 32, and a hollow support plate 33 for connecting the outer cylinder 31 and the inner cylinder 32; a number of pitot tubes 34 are installed on the hollow support plate 33, and a number of static pressure tubes 35 are installed on both the outer cylinder 31 and the inner cylinder 32. The pitot pressure measured by the pitot tubes 34 and the wall static pressure measured by the static pressure tubes 35 are used to determine the performance parameters of the main passage 82.

[0046] The air inlet passage performance measurement method is realized by a number of pitot tubes 34 installed on the support plate 33 of the measuring section and a number of static pressure tubes 35 installed on the outer cylinder 31 and the inner cylinder 32 of the measuring section. According to the pitot pressure measured by the pitot tubes 34, the wall static pressure measured by the static pressure tubes 35, and the aerodynamic theory, parameters such as the Mach number, total pressure recovery coefficient, and flow coefficient at the outlet of the passage 82 during the adjustment process of the air inlet passage structure are calculated; the calculation formulas are as follows:

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055] In the above formula, the subscript i represents the radial number of the pitot tube on each support plate 33 of the measuring section, with a total of I pitot tubes, numbered (1,..., I) from the inside outwards in sequence, such as Figure 2As shown; the subscript j represents the number of the struts 33 in the measurement section, with a total of J struts, numbered (1, …, J) in counterclockwise order from the bottom; γ is the specific heat ratio of the test gas, taken as 1.4; σ is the total pressure recovery coefficient; φ is the inlet duct flow capture coefficient; Ma1 is the average Mach number of the flow at the outlet of the inlet duct; p t,1 is the average total pressure of the flow at the outlet of the inlet duct; p t,2,i,j , Ma i,j , p t,1,i,j are respectively the pitot pressure, Mach number, and total pressure measured by the i-th pitot tube on the j-th strut in the measurement section; p1 is the arithmetic mean of the static pressures of all the wall surfaces; p 1,内壁,j , p 1,外壁,j are the static pressures on the inner wall and outer wall corresponding to the j-th strut in the measurement section; p t,∞ , Ma ∞ are respectively the total pressure and Mach number of the test incoming flow, given by the test; A ∞ is the ideal capture area of the inlet duct, given by the test; A1 is the area of the main channel 82 in the measurement section; q(Ma ∞ ), q(Ma i,j ) are flow functions obtained from the aerodynamics textbook by looking up the table according to Ma ∞ , Ma i,j .

[0056] The motor drive system 5 is a programmable controlled DC servo motor system with a speed reducer.

[0057] The lead screw pair 6 includes a slider 61 and a lead screw 62, and is used to convert the rotational motion of the motor drive system 5 into the linear motion of the slider 61.

[0058] The displacement sensor 7 is a magnetoresistive displacement sensor composed of a magnetic ring 71 and a guide rod scale 72.

[0059] The inlet duct passage 8 includes a bleed passage 81 and a main passage 82; the bleed passage 81 is a flow path formed by the bleed holes or slots 11 on the central cone 1, the hollow cavity 12 of the central cone 1, the bleed slots arranged in a staggered manner on the front and rear of the cylinder wall 41 of the fixed cylinder 4 and the hollow cavity 42 of the fixed cylinder 4, and the hollow slots of the struts 33 in the measurement section 3.

[0060] The gas flowing out from the bleed holes or slots 11 on the central cone 1 is discharged through the hollow slots of the hollow struts 33; the bleed passage 81 exhibits a double-throat characteristic; the first throat of the inlet duct bleed passage 81 is the bleed holes or slots 11; the second throat of the inlet duct bleed passage 81 is at the location of the minimum cross-sectional area of other downstream parts; the area of the second throat of the inlet duct bleed passage 81 is not less than 2 times the area of the first throat of the inlet duct bleed passage 81.

[0061] The main intake passage 82 is a connected flow path formed by the outer shell of the central cone 1, the inner wall of the outer cover 2, the outer cylinder 31, and the inner cylinder 32, presenting a double-throat characteristic. The first throat of the main intake passage 82 is the minimum flow cross-section formed by the outer shell of the central cone 1 and the inner wall of the outer cover 2. The second throat of the main intake passage 82 is the flow cross-section formed by the outer cylinder 31, the inner cylinder 32, and the hollow support plate 33. The area of the second throat of the main intake passage 82 is not less than 2.5 times the area of the first throat of the main intake passage 82.

[0062] The real-time position of the central cone 1 is given by the position of the displacement sensor magnetic ring 71 on the displacement sensor guide rod scale 72, where the central cone 1, the slider 61 of the lead screw pair 6, and the displacement sensor magnetic ring 71 are fixedly connected, and the position accuracy can reach 0.01 mm.

[0063] The central cone 1 and the fixed cylinder 4 are connected through a graphite copper sleeve 43. The graphite copper sleeve 43 is used to reduce the frictional resistance and for gas sealing of the main intake passage 82 during the adjustment process of the intake passage structure.

[0064] The motor drive system 5 is completely placed inside the inner cylinder 32 to avoid the erosion and heating of the motor drive system 5 by the airflow in the main intake passage 82, and solves the over-temperature problem of the motor drive system 5 faced in the intake passage wind tunnel test above Mach 5.

[0065] Figure 3 It is a schematic diagram of parameters such as the Mach number Ma at the outlet plane of the main intake passage, the total pressure recovery coefficient σ, and the flow coefficient φ during the structural adjustment process measured by the test system and method of the present invention.

[0066] The content not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.

[0067] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention all belong to the protection scope of the technical solution of the present invention.

Claims

1. A wind tunnel test system integrating the adjustment and performance measurement of a hypersonic inlet structure, characterized in that, Comprising: A hollow central cone (1), a hollow convergent outer shroud (2), a measurement section (3) connected to the outer shroud (2) and the central cone (1), a fixed cylinder (4) connected to the measurement section (3) and the central cone (1), a motor drive system (5) connected to the fixed cylinder (4), a lead screw pair (6) connected to the motor drive system (5) and the central cone (1), and a displacement sensor (7) connected to the fixed cylinder (4) and the lead screw pair (6); an air inlet passage (8) is formed between the outer surface of the central cone (1) and the inner cavity of the outer shroud (2); The central cone (1) can achieve controllable axial linear movement by means of the mechanism composed of the fixed cylinder (4), the motor drive system (5), and the lead screw pair (6), so as to adjust the minimum cross-sectional area of the main air inlet passage (82) of the air inlet passage (8); The measurement section (3) includes an outer cylinder (31), an inner cylinder (32), and a hollow support plate (33) for connecting the outer cylinder (31) and the inner cylinder (32); a number of pitot tubes (34) are installed on the hollow support plate (33), and a number of static pressure tubes (35) are installed on both the outer cylinder (31) and the inner cylinder (32). The pitot pressure measured by the pitot tubes (34) and the wall static pressure measured by the static pressure tubes (35) are used to determine the performance parameters of the main air inlet passage (82); The air inlet passage (8) includes an air inlet bleed passage (81) and a main air inlet passage (82); the air inlet bleed passage (81) is a flow path formed by the bleed holes or slots (11) on the central cone (1), the hollow cavity (12) of the central cone (1), the staggered bleed slots on the wall (41) of the fixed cylinder (4) and the hollow cavity (42) of the fixed cylinder (4), and the hollow slots of the hollow support plate (33) on the measurement section (3); The gas flowing out of the bleed holes or slots (11) on the central cone (1) is discharged through the hollow slots of the hollow support plate (33); the air inlet bleed passage (81) exhibits a double-throat characteristic; the first throat of the air inlet bleed passage (81) is the bleed holes or slots (11); the second throat of the air inlet bleed passage (81) is the location of the minimum cross-sectional area at other downstream parts; the area of the second throat of the air inlet bleed passage (81) is not less than twice the area of the first throat of the air inlet bleed passage (81); The motor drive system (5) is completely placed inside the inner cylinder (32).

2. The test system according to claim 1, characterized in that, The motor drive system (5) is a programmable controlled DC servo motor system with a reducer.

3. The test system according to claim 1, wherein The lead screw pair (6) includes a slider (61) and a lead screw (62), and is used to convert the rotational movement of the motor drive system (5) into the linear movement of the slider (61).

4. The test system according to claim 1, wherein The displacement sensor (7) is a magnetoresistive displacement sensor composed of a displacement sensor magnetic ring (71) and a displacement sensor guide rod scale (72).

5. The test system according to claim 4, wherein The real-time position of the central cone (1) is given by the position of the displacement sensor magnetic ring (71) on the displacement sensor guide rod scale (72), where the central cone (1), the slider (61) of the lead screw pair (6), and the displacement sensor magnetic ring (71) are fixedly connected to each other.

6. The test system according to claim 1, characterized in that, The performance parameters of the main inlet passage (82) include one or more of the outlet total pressure, Mach number, and flow rate.

7. The test system according to any one of claims 1 to 6, characterized in that, The main inlet passage (82) is a connected flow path formed by the outer shell of the central cone (1), the inner wall of the outer cover (2), the outer cylinder (31), and the inner cylinder (32), presenting a double-throat characteristic. The first throat of the main inlet passage (82) is the minimum flow cross-section formed by the outer shell of the central cone (1) and the inner wall of the outer cover (2). The second throat of the main inlet passage (82) is the flow cross-section formed by the outer cylinder (31), the inner cylinder (32), and the hollow support plate (33). The area of the second throat of the main inlet passage (82) is not less than 2.5 times the area of the first throat of the main inlet passage (82).

8. The test system according to any one of claims 1 to 6, characterized in that The central cone (1) is connected to the fixed cylinder (4) through a graphite copper sleeve (43), and the graphite copper sleeve (43) is used to reduce the frictional resistance and for gas sealing of the main inlet passage (82) during the adjustment process of the inlet passage structure.

9. A wind tunnel test method integrating the adjustment of a hypersonic inlet structure and the measurement of its performance, characterized in that, Using the test system according to any one of claims 1 to 6, comprising: Adjusting the minimum cross-sectional area of the main inlet passage (82) of the inlet passage (8). During the adjustment process of the inlet passage structure, the Mach number, total pressure recovery coefficient, and flow coefficient at the outlet of the main inlet passage (82) are determined as follows: In the above formula, the subscript i represents the radial number of the pitot tube on the hollow strut (33) in each measurement section, with a total of I; the subscript j represents the number of the hollow strut (33) in the measurement section, with a total of J; γ is the specific heat ratio of the test gas; σ is the total pressure recovery coefficient; φ is the intake duct flow capture coefficient; Ma1 is the average Mach number of the flow at the intake duct outlet; p t,1 is the average total pressure of the flow at the intake duct outlet; p t,2,i,j , Ma i,j , p t,1,i,j are respectively the pitot pressure, Mach number and total pressure measured by the i-th pitot tube on the j-th hollow strut (33) in the measurement section; p1 is the arithmetic mean of all wall static pressures; p 1,内壁,j , p 1,外壁,j are the wall static pressures on the inner wall and outer wall corresponding to the j-th hollow strut (33) in the measurement section; p t,∞ , Ma ∞ are respectively the total pressure and Mach number of the test incoming flow, which are given by the test; A ∞ is the ideal capture area of the intake duct, which is given by the test; A1 is the area of the main channel (82) of the intake duct in the measurement section; q(Ma ∞ ), q(Ma i,j ) are flow functions obtained by looking up the table from the aerodynamics textbook according to Ma ∞ , Ma i,j .

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