A method for troubleshooting data anomalies in multiple-engine interference inlet tests

Abstract

A method for troubleshooting data anomalies in multiple interference inlet duct tests, belonging to the field of wind tunnel test technology, includes assembling and arranging the test model before the test; drawing the test data performance curve and the inlet duct outlet total pressure spectrum, finding the jump points and corresponding flow points that are different from normal data; checking the wind tunnel and test equipment; controlling the throttle cone to run continuously, while the flow meter measurement section, the inlet duct outlet measurement section and the wall pressure measurement point respectively continuously collect all pressure measurement point data; drawing the continuous measurement structure time history curve; analyzing the data, diagnosing the data jump point caused by the aerodynamic phenomenon of the model itself. The problem of using conventional steady-state pressure continuous measurement test methods to troubleshoot and diagnose data anomalies caused by flow phenomena is solved. The present invention can be applied to the diagnosis of inlet duct data anomalies in different flow rate ranges such as low speed, high speed, supersonic speed, and hypersonic speed. The method is easy to implement, simple to implement, low in diagnostic cost, and widely applicable.

Description

Technical Field

[0001] The invention relates to a method for checking data anomalies in a multi-engine interference inlet duct test, and belongs to the technical field of wind tunnel tests. Background Art

[0002] The air inlet is one of the important components of the power plant of an air-breathing aircraft. In order to study and evaluate the aerodynamic performance of the air inlet designed for an aircraft in a wind tunnel test, it is usually necessary to conduct corresponding tests on the air inlet model through a wind tunnel test to measure the aerodynamic performance differences of the air inlet model under different Mach numbers of the incoming flow and the influence of the internal or external components of the air inlet on the aerodynamic performance of the air inlet.

[0003] In the wind tunnel test of multiple inlet layouts, an important test project is the multi-engine interference project, which is used to simulate the aerodynamic interference of the inlet flow field of the inlet duct on other normal working inlet ducts when a single engine or multiple engines fail or even stop in the air, and evaluate the impact of changes in the flow of one or more inlet ducts on the aerodynamic performance of other normal working inlet ducts. During the test, some test problems are inevitable, usually caused by various objective and human factors such as model defects, wind tunnel and test equipment failures, parameter errors, etc. The data anomalies caused by these problems can generally be quickly checked and resolved by intuitive data observation and comparison by experienced test personnel. However, in multi-engine interference tests, due to aerodynamic phenomena such as vortexes or shock waves emanating from the fuselage or other external components that happen to be sucked into a certain inlet within a certain flow range, affecting the inlet flow field of the inlet, or single-engine failure interfering with the flow fields of other inlets, test data may show abnormalities such as jump points. Even if there are unique signal features, it is difficult to distinguish the jump points from the test equipment failure in the overall data trend, making it difficult for test personnel to make direct judgments based solely on troubleshooting of the test equipment and conventional test experience, thereby delaying the test progress and greatly reducing the test efficiency.

[0004] Therefore, in order to find out whether the data anomaly is caused by aerodynamic phenomena, it is best to use flow field visualization technology to reproduce the inlet flow field conditions for investigation and judgment in addition to checking the wind tunnel flow field, test equipment, model status, data recalculation and comparison by conventional means. However, it is not convenient to directly use wind tunnel flow field visualization methods at many wind tunnel test sites. The installation and use takes a long time, the cost is high, the efficiency is low, and it cannot be quickly deployed and used when needed. Some wind tunnels do not even have the configuration visualization method, so the operability is not strong in the actual test process.

[0005] Therefore, it is urgent to propose a method for troubleshooting data anomalies in multi-engine interference inlet tests to solve the above technical problems. Summary of the invention

[0006] The purpose of the present invention is to solve the problem of using conventional steady-state pressure continuous measurement test methods to troubleshoot and diagnose data anomalies caused by flow phenomena. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0007] The technical solution of the present invention:

[0008] A method for troubleshooting data anomalies in a multi-engine interference inlet test, comprising:

[0009] S1, assemble and arrange the test model before the test, the test model includes a front body, a throttle cone and a wall pressure measuring point, the front body has an inner flow channel that runs through from front to back, the front port of the inner flow channel is the inlet of the air inlet, the bottom surface of the front end of the inner flow channel is provided with a compression surface, the inner flow channel is provided with an air inlet outlet measuring section, the inner flow channel is provided with a flow meter measuring section at the rear outlet of the inner flow channel, a throttle cone is provided at the rear side of the inner flow channel, and a plurality of wall pressure measuring points are arranged on the wall of the inner flow channel;

[0010] S2, draw the test data performance curve and the inlet outlet total pressure map, find out the jump points and corresponding flow points that are different from normal data;

[0011] S3, check the wind tunnel and test equipment;

[0012] S4, controlling the throttle cone to run continuously, while the flow meter measurement section, the inlet duct outlet measurement section and the wall pressure measurement point respectively continuously collect data from all pressure measurement points;

[0013] S5, draw the time history curve of the continuous measurement structure;

[0014] S6, analyze the data and diagnose data anomalies caused by the aerodynamic phenomenon of the model itself.

[0015] Preferably: the test conditions for controlling the continuous operation of the throttle cone in S4 include the wind tunnel test Mach number, the test total pressure, the angle of attack, the sideslip angle and the flow point, and the throttle cone is controlled to continuously run through all flow points of the flow meter measurement section, the inlet duct outlet measurement section and the wall pressure measuring point, and at the same time, the flow meter measurement section, the inlet duct outlet measurement section and the wall pressure measuring point are all electrically connected to the steady-state pressure measurement system, and the steady-state pressure measurement system acquires all flow point data in a continuous acquisition manner.

[0016] Preferably: the data analyzed in S6 includes taking the inlet of the air inlet as the boundary, analyzing the pressure changes of the pressure measuring points before and after the inlet of the air inlet, focusing on analyzing the typical characteristics of the model's geometric shape and the pressure changes of the pressure measuring points collected at the wall pressure measuring points at positions with large flow changes, comparing the pressure waveform characteristics in the time domain of steady-state continuous measurement data of jump points and non-jump points, combining the continuous measurement curve characteristics of the left-right geometric symmetry of the inner flow channel but the asymmetric data, so as to diagnose that the data jump point is a data anomaly caused by the aerodynamic phenomenon of the test model itself.

[0017] The present invention has the following beneficial effects:

[0018] 1. The present invention can be applied to the abnormal diagnosis of inlet data in different flow velocity ranges such as low speed, high speed, supersonic speed, and hypersonic speed. The method is easy to implement, simple to implement, low in diagnostic cost, and wide in applicability.

[0019] 2. The present invention adopts a steady-state pressure measurement system to continuously collect data for a certain period of time from the pressure measuring points of the intake duct model at different flow points, draws a time history curve of the continuously collected data at the pressure measuring points, analyzes the law of change of the pressure waveform of each curve with the position, and determines whether the data anomaly is caused by flow phenomenon. It is highly operational in the actual test process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic diagram of the structure of the test model of the present invention;

[0021] FIG2 is a flow chart of the method of the present invention;

[0022] FIG3 is a test jump point curve diagram of the present invention;

[0023] FIG4 is a continuous measurement curve diagram of each cross section of the present invention, in which (a) is the continuous measurement result of the jump point, and (b) is the continuous measurement result of the maximum flow point;

[0024] FIG5 is a dynamic pressure curve diagram of the present invention, wherein (a) is the dynamic pressure result of the left lip of the inlet of the air duct at the jump point, (b) is the dynamic pressure structure of the right lip of the inlet of the air duct at the jump point, (c) is the dynamic pressure result of the left lip of the inlet of the air duct at the maximum flow point, and (d) is the dynamic pressure result of the right lip of the inlet of the air duct at the maximum flow point.

[0025] In the figure: 1-front body, 2-compression surface, 3-inlet duct inlet, 4-inner flow channel, 5-inlet duct outlet measurement section, 6-flow meter measurement section, 7-throttling cone, 8-wall pressure measuring point. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0027] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection (i.e., non-detachable connection) includes but is not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but is not limited to conventional detachable methods such as threaded connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can always be found in the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs. For example: welding connection is selected for fixed connection, and hinge connection is selected for detachable connection.

[0028] Specific implementation method 1: Combination Figure 1-Figure 5 The present embodiment is described. A method for troubleshooting data anomalies in a multi-engine interference inlet test in the present embodiment includes:

[0029] S1, assemble and arrange the test model before the test, the test model includes a front body 1, a throttling cone 7 and a wall pressure measuring point 8, the front body 1 has an inner flow channel 4 that runs through from front to back, the front port of the inner flow channel 4 is an air inlet 3, the bottom surface of the front end of the inner flow channel 4 is provided with a compression surface 2, the inner flow channel 4 is provided with an air inlet outlet measuring section 5, the inner flow channel 4 is provided with a flow meter measuring section 6 at the rear outlet, the inner flow channel 4 is provided with a throttling cone 7 at the rear side, and a plurality of wall pressure measuring points 8 are arranged on the wall of the inner flow channel 4;

[0030] S2, draw the test data performance curve and the inlet outlet total pressure map, find out the jump points and corresponding flow points that are different from normal data;

[0031] S3, check the wind tunnel and test equipment, which can be checked through measured data and test condition calibration;

[0032] S4, control the throttle cone to run continuously, and at the same time, the flow meter measuring section 6, the inlet outlet measuring section 5 and the wall pressure measuring point 8 respectively continuously collect data from all pressure measuring points;

[0033] S5, draw the time history curve of the continuous measurement structure;

[0034] S6, analyze the data and diagnose data anomalies caused by the aerodynamic phenomenon of the model itself.

[0035] In the step S1, before the test, the wall pressure measuring points 8 are arranged in the order of the front body 1, the air inlet 3, the internal flow channel 4, the internal flow channel 4 outlet, and the flow meter measurement section 6. The wall pressure measuring points 8 include steady-state pressure points and dynamic pressure points. Such positions are commonly used reference positions for air inlet flow field analysis, and the relative changes in flow field pressure are relatively obvious.

[0036] The test data performance curves in S2 include a σ~Wc performance curve and a Tu~Wc performance curve, wherein σ is the inlet duct total pressure recovery coefficient, Wc is the engine converted flow rate, and Tu is the inlet duct outlet turbulence.

[0037] There are two forms of the inlet total pressure recovery coefficient σ, one is the arithmetic mean total pressure recovery coefficient (CGMAS), and the other is the flow average total pressure recovery coefficient (CGMA).

[0038] (1) When the inlet total pressure recovery coefficient σ is the arithmetic mean total pressure recovery coefficient (CGMAS), the calculation formula is as follows:

[0039] ;

[0040] ;

[0041] In the formula, is the arithmetic mean of the m×n steady-state total pressure points in the inlet outlet measurement section 5, It is the steady-state total pressure value on the rth ring of the ith rake at the inlet outlet section 5, m is the number of rakes, usually m=8, n is the number of rings, usually n=5.

[0042] (2) When the inlet total pressure recovery coefficient σ is the flow average total pressure recovery coefficient (CGMA), the calculation formula is as follows:

[0043] ;

[0044] ;

[0045] ;

[0046] ;

[0047] In the formula, is the average flow rate of m×n steady-state total pressure points in the inlet outlet section 5, is the steady-state total pressure value on the rth ring of the ith rake at the inlet outlet section 5, is the velocity function of the rth ring on the ith rake of the inlet outlet section 5, is the arithmetic mean steady-state static pressure at the inlet outlet, m is the rake number, usually m=8, and n is the number of rings, usually n=5.

[0048] (3) The calculation formula for the turbulence degree Tu at the rear outlet of the inner flow channel 4 is as follows:

[0049] ;

[0050] ;

[0051] ;

[0052] In the formula, is the pulsating total pressure measured by the dynamic sensor installed in the flow meter measurement section 6; T is the dynamic acquisition time, in seconds; f is the dynamic acquisition frequency, To collect The arithmetic mean of the total pulsation pressure values; is the arithmetic mean of the m×n steady-state total pressure points in the inlet outlet section 5; is the turbulence calculated by the dynamic sensor of each flow meter measuring section 6; J is the number of dynamic sensors installed in the flow meter measuring section 6; Tu is the average turbulence calculated by all dynamic sensors installed in the flow meter measuring section 6.

[0053] (4) Total pressure spectrum at the inlet outlet

[0054] The m×n steady-state total pressure points in the inlet outlet section 5 are encrypted by interpolation (which may be linear interpolation, Kriging, etc.), and the inlet outlet total pressure map is drawn using post-processing software such as tecplot.

[0055] In S2, find the jump points and corresponding traffic points that are different from normal data. Figure 3 The test jump point curve diagram is used to determine the jump points and corresponding flow points that are different from normal data according to the jump point judgment basis, and the jump point judgment basis is to determine the abnormal points through the statistical 3 sigma criterion.

[0056] The test conditions for controlling the continuous operation of the throttle cone in S4 include the wind tunnel test Mach number Ma, the test total pressure , angle of attack α, sideslip angle β and flow point, control the throttle cone 7 to continuously run through all flow points of the flow meter measurement section 6, the inlet duct outlet measurement section 5 and the wall pressure measurement point 8. At the same time, the flow meter measurement section 6, the inlet duct outlet measurement section 5 and the wall pressure measurement point 8 are all electrically connected to the steady-state pressure measurement system, and the steady-state pressure measurement system collects all flow point data in a continuous acquisition manner. If conditions permit, a dynamic pressure sensor can be arranged on the model to continuously collect dynamic pressure data at the same time.

[0057] In S5, for the jump point and the maximum flow point, the time history curve corresponding to the steady-state continuous measurement result is drawn in one figure respectively, see Figure 4 The continuous measurement curves of each cross section are plotted, and the pressure measuring points at the typical locations of the model geometry and the locations with large flow changes are selected to draw the pressure curves;

[0058] See Figure 5 Dynamic pressure curve of Figure 4 The time history curves of continuous measurement data of the nose, the compression surface of the air inlet lip, the air inlet lips on both sides, the measuring section and the pressure measuring points of the flowmeter are given in the figure. Comparing the continuous measurement curves of the jump point and the maximum flow point, it can be seen that the static pressure change of the nose of the front fuselage 1 before the air inlet 3 is very small, and the waveform amplitude is very small, but starting from the static pressure measurement point of the lip compression surface of the air inlet 3, the jump point flow point has a periodic change feature here, and at the air inlet 3 lip, the pressure waveform amplitude of the static pressure measuring point has increased to a great extent, and the direction is unidirectional oscillation, all the way to the static pressure of the measuring section at the outlet of the inner flow channel 4, the waveform characteristics are similar, and the maximum flow point of the non-jump point flow is from the nose pressure measuring point of the front fuselage 1 to the static pressure of the measuring section, the waveform is very stable, and no large oscillation occurs.

[0059] The data analyzed in S6 includes analyzing the pressure changes at the pressure measuring points before and after the air inlet 3 with the air inlet 3 as the boundary, focusing on analyzing the typical characteristics of the model's geometric shape and the pressure changes at the pressure measuring points 8 on the wall where the flow changes are large, comparing the pressure waveform characteristics of the steady-state continuous measurement data of the jump point and the non-jump point flow points in the time domain, such as the oscillation shape, amplitude, mean and frequency distribution characteristics in the frequency domain, combined with the continuous measurement curve characteristics of the inner flow channel 4 with left-right geometric symmetry but asymmetric data, thereby diagnosing that the data jump point is a data anomaly caused by the aerodynamic phenomenon of the test model itself.

[0060] If dynamic pressure data is collected, it can be analyzed together with the steady-state and dynamic pressure data to provide more sufficient basis for diagnosis.

[0061] By comparing the pressure waveform characteristics in the time domain of the steady-state continuous measurement data of the jump point and non-jump point flow points, that is, the static and dynamic pressure results at the left and right lips of the jump point and the maximum flow point, it can be seen that the dynamic pressure waveform of the static pressure at the left lip of the inlet 3 of the jump point is very similar to the steady-state continuous measurement pressure waveform of the static pressure at the left lip of the inlet 3 of the jump point, and the dynamic pressure waveform at the maximum flow point is also very similar to the steady-state continuous measurement pressure waveform.

[0062] Based on the above data analysis, it can be seen that the waveform of the steady-state continuous measurement pressure acquisition signal of the jump point has changed significantly from the lip compression surface. At some typical positions, the steady-state continuous acquisition results and the dynamic acquisition results have similar characteristics. The steady-state continuous acquisition results and the dynamic acquisition results of the non-jump point flow points are also similar in characteristics, indicating that the flow in the left inlet channel 4 is disturbed by the flow outside the inlet, resulting in a jump point in the left performance, rather than a problem with the data acquisition measurement;

[0063] The curve similarity determination method includes the Euclidean distance algorithm and the correlation coefficient algorithm. The similarity in the characteristics is first evaluated from a graphical perspective by comparing the curve's ups and downs, curvature, trend, periodicity, peaks, valleys, data point density and distribution, and then by calculating the distance between the curves to evaluate the similarity.

[0064] The throttle cone 7 is used to adjust the back pressure of the intake duct, thereby adjusting the flow rate of the intake duct.

[0065] The moving speed of the throttle cone 7 is determined according to the wind tunnel operation time and the pressure measurement stabilization time, and is generally set to 1-6 mm / s.

[0066] The steady-state pressure measurement system is usually a pressure scanning valve system, and the scanning frequency of the scanning valve is usually set according to the maximum scanning capacity of the device.

[0067] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for troubleshooting data anomalies in a multi-engine interference inlet test, characterized in that: include: S1, assembling and arranging a test model before the test, the test model comprising a front body (1), a throttling cone (7) and a wall pressure measuring point (8), the front body (1) having an inner flow channel (4) that is connected from front to back, the front port of the inner flow channel (4) being an air inlet (3), the bottom surface of the front end of the inner flow channel (4) being provided with a compression surface (2), the inner flow channel (4) being provided with an air inlet outlet measuring section (5), the inner flow channel (4) being provided with a flow meter measuring section (6) at the rear outlet, the inner flow channel (4) being provided with a throttling cone (7) at the rear side, and a plurality of wall pressure measuring points (8) being arranged on the wall of the inner flow channel (4); S2, draw the test data performance curve and the inlet outlet total pressure map, find out the jump points and corresponding flow points that are different from normal data; S3, check the wind tunnel and test equipment; S4, controlling the throttle cone to run continuously, while the flow meter measuring section (6), the inlet duct outlet measuring section (5) and the wall pressure measuring point (8) respectively continuously collect data from all pressure measuring points; S5, draw the time history curve of the continuous measurement structure; S6, analyze the data and diagnose the data anomalies caused by the aerodynamic phenomenon of the model itself; The data analyzed in S6 includes taking the air inlet (3) as the boundary, analyzing the pressure changes of the pressure measuring points before and after the air inlet (3), focusing on analyzing the typical characteristics of the model's geometric shape and the pressure changes of the pressure measuring points collected at the wall pressure measuring points (8) at the position where the flow changes are large, comparing the pressure waveform characteristics of the steady-state continuous measurement data of the jump point and the non-jump point flow point in the time domain, and combining the continuous measurement curve characteristics of the inner flow channel (4) with left-right geometric symmetry but asymmetric data, thereby diagnosing that the data jump point is a data anomaly caused by the aerodynamic phenomenon of the test model itself.

2. The method for troubleshooting data anomalies in a multi-engine interference inlet test according to claim 1, characterized in that: The test conditions for controlling the continuous operation of the throttle cone in S4 include the wind tunnel test Mach number, the test total pressure, the angle of attack, the sideslip angle and the flow point, and the throttle cone (7) is controlled to continuously run through all the flow points of the flow meter measurement section (6), the inlet duct outlet measurement section (5) and the wall pressure measurement point (8). At the same time, the flow meter measurement section (6), the inlet duct outlet measurement section (5) and the wall pressure measurement point (8) are all electrically connected to the steady-state pressure measurement system, and the steady-state pressure measurement system collects all the flow point data in a continuous collection manner.

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