A high-turbulence pressure distortion simulation method based on the acceleration principle

Abstract

The present invention provides a high-turbulence pressure distortion simulation method based on the acceleration principle, comprising the following steps: Step 1, perform the design of the acceleration part and the design of the pressure distortion part; Step 2, combine the acceleration part and the pressure distortion part into an integral whole and conduct numerical simulation; Step 3, when the pressure field of the numerical simulation meets the set requirements, machine the scaled-down model part and enter Step 4; when the pressure field of the numerical simulation does not meet the set requirements, adjust the pressure distortion part according to the numerical simulation results and repeat Step 2; Step 4, conduct a blowing test on the scaled-down model part to obtain the parameters of the outlet flow field of the scaled-down model part; Step 5, when the parameters of the outlet flow field of the scaled-down model part meet the set requirements, determine the actual size of the pressure distortion simulation device according to the size of the scaled-down model part; when the parameters of the outlet flow field of the scaled-down model part do not meet the set requirements, adjust the acceleration part and / or the pressure distortion part and repeat Step 4.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and particularly relates to a method for simulating high-turbulence pressure distortion based on the acceleration principle. Background Art

[0002] Since the inlet duct / engine compatibility problem attracted international attention in the 1960s, countries have paid more and more attention to the simulation research on the inlet flow field distortion of engines. Due to the excessively high cost required for the combined test of the inlet duct and the engine, various inlet distortion simulation technologies have emerged. Through these simulation technologies, a flow field consistent with the distortion effect at the outlet of the inlet duct can be generated.

[0003] There are various types of simulation devices for the engine inlet flow field, such as grid distortion simulators, random frequency simulators, orifice simulators, and plate spoilers. Different types of distortion devices have their own characteristics. Among them, the orifice simulator is a distortion test device recommended in the general specification because of its simplicity, effectiveness, and economy. However, compared with the steady-state distortion index (circumferential total pressure non-uniformity), the dynamic distortion index (turbulence) generated by the orifice simulator is generally low, and the dynamic-to-steady ratio is generally 1:8 to 1:5, and it is impossible to simultaneously simulate the steady-state distortion index and the dynamic distortion index of the inlet flow field at the outlet of the inlet duct. Summary of the Invention

[0004] In view of this, the present invention provides a method for simulating high-turbulence pressure distortion based on the acceleration principle, so as to achieve the purpose of increasing the turbulence generated in the pressure distortion simulation method based on the orifice simulator.

[0005] The present invention provides the following technical solutions: A method for simulating high-turbulence pressure distortion based on the acceleration principle includes the following steps: Step 1, perform the design of the acceleration part and the design of the pressure distortion part; Step 2, combine the acceleration part and the pressure distortion part into a whole and perform numerical simulation; Step 3, when the pressure field of the numerical simulation meets the set requirements, machine a scaled-down model part and enter Step 4; when the pressure field of the numerical simulation does not meet the set requirements, adjust the pressure distortion part according to the numerical simulation results and repeat Step 2; Step 4, conduct a blowing test on the scaled-down model part to obtain the parameters of the flow field at the outlet of the scaled-down model part; Step 5, when the parameters of the flow field at the outlet of the scaled-down model part meet the set requirements, determine the actual size of the pressure distortion simulation device according to the size of the scaled-down model part; when the parameters of the flow field at the outlet of the scaled-down model part do not meet the set requirements, adjust the acceleration part and / or the pressure distortion part and repeat Step 4.

[0006] Further, the design of the acceleration part includes: designing multiple groups of acceleration blocks according to 0.5 to 0.9 times the pipe area of the pressure distortion simulation device; designing multiple groups of acceleration sections according to 0.4 to 2.0 times the pipe diameter of the pressure distortion simulation device; creating a three-dimensional model of the acceleration block and the acceleration section.

[0007] Furthermore, the shapes of the acceleration blocks include annular, crescent, and straight plate shapes.

[0008] Furthermore, the design of the pressure distortion part includes: determining the pressure field distribution according to the target map; generating a set multiple average pressure curve according to the pressure field distribution; arranging spoiler baffles in the area below the set multiple average pressure curve; opening holes on the spoiler baffles according to the pressure gradient; creating a three-dimensional model of the pressure distortion plate.

[0009] Furthermore, when combining the acceleration part and the pressure distortion part into an integral whole, the acceleration part is located at the front end of the pressure distortion part.

[0010] Furthermore, when the pressure field of the numerical simulation does not meet the set requirements, readjust the hole size, hole form, or hole position of the pressure distortion part.

[0011] Furthermore, the parameters of the outlet flow field of the scaled model part are specifically the pressure field and turbulence intensity of the outlet flow field of the scaled model part.

[0012] Furthermore, when the parameters of the outlet flow field of the scaled model part do not meet the set requirements, adjust the acceleration part and / or the pressure distortion part and repeat Step 4 specifically: when the turbulence intensity does not meet the set requirements, replace acceleration blocks with different areas and acceleration sections with different lengths and conduct the scaled model part blowing test again.

[0013] Furthermore, when the parameters of the outlet flow field of the scaled model part do not meet the set requirements, adjust the acceleration part and / or the pressure distortion part and repeat Step 4 specifically: when the pressure field does not meet the set requirements, adjust the hole size, hole form, or hole position of the pressure distortion plate and conduct the scaled model part blowing test again.

[0014] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the present invention at least include: the present invention can increase the turbulence intensity generated in the pressure distortion simulation method based on the orifice simulator, enabling the surface average turbulence intensity generated by the pressure distortion simulation device to reach more than 5%, and the ratio of dynamic distortion to steady-state distortion to reach 1:2 - 3:2, making it possible to simultaneously simulate the steady-state distortion index and the dynamic distortion index of the pressure distortion flow field at the inlet duct outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a design flow chart of a high-turbulence simulation device based on the acceleration principle;

[0017] Figure 2 It is a schematic diagram of the target spectrum;

[0018] Figure 3 It is a schematic diagram of the acceleration block;

[0019] Figure 4 It is a schematic diagram of the acceleration section with a length of 0.4 times the pipe diameter;

[0020] Figure 5 It is a schematic diagram of the acceleration section with a length of 0.8 times the pipe diameter;

[0021] Figure 6 It is a schematic diagram of the isobar distribution;

[0022] Figure 7 It is a schematic diagram of the curve of 0.98 times the average pressure;

[0023] Figure 8 It is a schematic diagram of the completion of the opening in the baffle area;

[0024] Figure 9 It is a schematic diagram of the model part. Specific implementation manners

[0025] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0026] The following describes the implementation manners of the present application through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts belong to the scope of protection of the present application.

[0027] As Figure 1 shown, the embodiments of the present invention provide a high-turbulence pressure distortion simulation method based on the acceleration principle, including the following steps:

[0028] Step 1: Design the acceleration part and the pressure distortion part;

[0029] Step 2: Combine the acceleration part and the pressure distortion part into a whole and perform numerical simulation;

[0030] Step 3: When the pressure field in the numerical simulation meets the set requirements, process the scaled-down model part and proceed to Step 4; when the pressure field in the numerical simulation does not meet the set requirements, adjust the pressure distortion part according to the numerical simulation results and repeat Step 2.

[0031] Step 4: Conduct a blowing test on the scaled-down model part to obtain the parameters of the flow field at the outlet of the scaled-down model part.

[0032] Step 5: When the parameters of the flow field at the outlet of the scaled-down model part meet the set requirements, determine the actual size of the pressure distortion simulation device according to the size of the scaled-down model part; when the parameters of the flow field at the outlet of the scaled-down model part do not meet the set requirements, adjust the acceleration part and / or the pressure distortion part and repeat Step 4.

[0033] The high-turbulence pressure distortion simulation method based on the acceleration principle of the present invention accelerates the air flow in front of the pressure distortion plate through the action of the acceleration plate and the acceleration section, impacts the pressure distortion simulation plate, and generates high turbulence behind the pressure distortion simulation plate, realizing the simultaneous simulation of the turbulence intensity and the circumferential pressure distortion index.

[0034] The design of the acceleration part includes:

[0035] Design multiple groups of acceleration blocks according to 0.5 - 0.9 times the pipe area of the pressure distortion simulation device.

[0036] Design multiple groups of acceleration sections according to 0.4 - 2.0 times the pipe diameter of the pressure distortion simulation device.

[0037] Create a 3D model of the acceleration block and the acceleration section.

[0038] It should be noted that the shapes of the acceleration blocks in the embodiments of the present invention include circular ring shape, crescent shape, and straight plate shape.

[0039] The design of the pressure distortion part includes:

[0040] Determine the pressure field distribution according to the target map.

[0041] Generate an average pressure curve of a set multiple according to the pressure field distribution.

[0042] Set spoiler baffles in the area below the average pressure curve of the set multiple.

[0043] Open holes on the spoiler baffles according to the pressure gradient.

[0044] Create a 3D model of the pressure distortion plate.

[0045] Furthermore, when combining the acceleration part and the pressure distortion part into a whole, make the acceleration part located at the front end of the pressure distortion part.

[0046] In the embodiments of the present invention, when the pressure field of the numerical simulation does not meet the set requirements, the opening size, opening form or opening position of the pressure distortion part is readjusted.

[0047] It should be noted that the parameters of the outlet flow field of the scaled model are specifically the pressure field and turbulence intensity of the outlet flow field of the scaled model.

[0048] When the parameters of the outlet flow field of the scaled model do not meet the set requirements, the adjustment of the acceleration part and / or the pressure distortion part and the repetition of step four are specifically as follows:

[0049] When the turbulence intensity does not meet the set requirements, acceleration blocks with different areas and acceleration sections with different lengths are replaced and the blowing test of the scaled model is carried out again.

[0050] When the parameters of the outlet flow field of the scaled model do not meet the set requirements, the adjustment of the acceleration part and / or the pressure distortion part and the repetition of step four are specifically as follows:

[0051] When the pressure field does not meet the set requirements, the opening size, opening form or opening position of the pressure distortion plate is adjusted, and the blowing test of the scaled model is carried out again.

[0052] The following is illustrated by a specific embodiment:

[0053] A. Design the acceleration part;

[0054] 1) The target map is as Figure 2 shown. The target operating condition AIP Mach number is 0.2, the turbulence intensity is 2.1%, and the circumferential non-uniformity is 3.5%;

[0055] 2) Design the acceleration blocks. Considering that the target operating condition AIP Mach number is small, only 0.2, three acceleration blocks are designed according to 0.6 times the pipe area, 0.7 times the pipe area and 0.8 times the pipe area; considering that the pipe cross-section is circular, they are designed as annular throttle acceleration blocks. The three designed acceleration blocks are as Figure 3 shown, where Figure 3 from left to right are the schematic diagrams of 60% pipe area, 70% pipe area and 80% pipe area respectively;

[0056] 3) Design the acceleration sections. Considering that the target operating condition AIP Mach number is small, only 0.2, one group is designed for each of the acceleration section lengths of 0.4 times the pipe diameter and 0.8 times the pipe diameter, with a total of two groups designed. Through combination, three groups of acceleration sections with lengths of 0.4 times the pipe diameter, 0.8 times the pipe diameter and 1.2 times the pipe diameter can be formed respectively. The two designed acceleration sections are as Figure 4 and Figure 5 shown, where Figure 4 is the schematic diagram of the acceleration section with a length of 0.4 times the pipe diameter and Figure 5Schematic diagram of the acceleration section with a length of 0.8 times the pipe diameter;

[0057] 4) Create the three-dimensional model entity of the acceleration block and the acceleration section.

[0058] B. Design of the pressure distortion part;

[0059] 1) Define the pressure field distribution of the target map (see Figure 2 );

[0060] 2) Generate the isobaric diagram according to the pressure field distribution of the target map (see Figure 6 ), and extract the data of the 0.98 times average pressure curve from it;

[0061] 3) Taking the 0.98 times average pressure curve as the boundary, set the flow disturbance baffle in the area with a pressure less than 0.98 times the pressure, and do not set it in the remaining areas (see Figure 7 );

[0062] 4) In the baffle area, draw the isobars of 0.94 times average pressure and 0.96 times average pressure. According to the pressure gradient, the higher the pressure, the more and larger the openings are, and the lower the pressure, the fewer and smaller the openings are (see Figure 8 );

[0063] 5) Create the three-dimensional model entity of the pressure distortion plate.

[0064] C. Combine the acceleration part and the pressure distortion part into a whole, with the acceleration part at the front end and the pressure distortion part at the rear end, conduct the overall numerical simulation, and compare the outlet flow field of the numerical simulation with the target map;

[0065] D. Through numerical simulation and two rounds of iteration, after adjusting the opening form and size in the baffle area, the pressure map of the outlet flow field is similar to the target map. At the same time, the circumferential pressure distortion index is 1.4 times that of the target map, and the pressure distortion part meets the requirements;

[0066] E. Machine the scaled-down model part (see Figure 9 ), and the diameter of the scaled-down model part is 200 mm;

[0067] F. Conduct the blowing test on the scaled-down model part to obtain the outlet pressure distribution, turbulence intensity, and circumferential pressure distortion index of the model part; during the test, the acceleration block and the acceleration section were adjusted many times. After using the acceleration block with 70% of the pipe area and the acceleration section with a length of 0.4 times the pipe diameter, the turbulence intensity at the outlet of the device reaches 1.9%, meeting the requirements of the target turbulence intensity;

[0068] G. During the blowing test of the scaled-down model part, the pressure distortion plate was slightly adjusted. Finally, the circumferential pressure non-uniformity is 3.7%, and the comprehensive distortion index is 5.6%;

[0069] H. The curve dimensions of the pressure distortion plate were detected using a coordinate measuring instrument. The pressure distortion plate, acceleration block, and acceleration section were enlarged proportionally to complete the simulation design of high-turbulence pressure distortion based on the acceleration principle.

[0070] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A high turbulence pressure distortion simulation method based on acceleration principle, characterized in that: The following steps are involved: Step 1: Design the acceleration part and the pressure distortion part; Step 2: Combine the acceleration part and the pressure distortion part into a whole and perform numerical simulation; Step 3: When the pressure field of the numerical simulation meets the set requirements, the scaled model is processed and step 4 is entered; when the pressure field of the numerical simulation does not meet the set requirements, the pressure distortion part is adjusted according to the numerical simulation results and step 2 is repeated; Step 4: Conduct a blow test on the scaled model to obtain the parameters of the outlet flow field of the scaled model; Step 5: When the parameters of the outlet flow field of the scaled model meet the set requirements, the actual size of the pressure distortion simulation device is determined according to the size of the scaled model; When the parameters of the outlet flow field of the scaled model do not meet the set requirements, the acceleration part and / or the pressure distortion part are adjusted and step 4 is repeated; The design of the acceleration part includes: designing multiple groups of acceleration blocks according to 0.5~0.9 times the pipeline area of ​​the pressure distortion simulation device; designing multiple groups of acceleration sections according to 0.4~2.0 times the pipeline diameter of the pressure distortion simulation device; creating a three-dimensional model of the acceleration blocks and acceleration sections; The design of the pressure distortion part includes: determining the pressure field distribution according to the target map; generating a set multiple average pressure curve according to the pressure field distribution; setting a spoiler baffle in an area less than the set multiple average pressure curve; opening holes on the spoiler baffle according to the pressure gradient; and creating a three-dimensional model of the pressure distortion plate.

2. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 1 is characterized in that: The shapes of the acceleration blocks include circular ring, crescent and straight plate.

3. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 1 is characterized in that: When the acceleration part and the pressure distortion part are combined into a whole, the acceleration part is located at the front end of the pressure distortion part.

4. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 3 is characterized in that: When the pressure field of the numerical simulation does not meet the set requirements, the opening size, opening form or opening position of the pressure distortion part is readjusted.

5. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 4 is characterized in that: The parameters of the outlet flow field of the scaled model component are specifically the pressure field and turbulence of the outlet flow field of the scaled model component.

6. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 5 is characterized in that: When the parameters of the outlet flow field of the scaled model do not meet the set requirements, the acceleration part and / or the pressure distortion part are adjusted and step 4 is repeated. Specifically: When the turbulence does not meet the set requirements, replace the acceleration blocks with different areas and the acceleration sections with different lengths and re-conduct the wind blowing test on the scaled model.

7. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 5 is characterized in that: When the parameters of the outlet flow field of the scaled model do not meet the set requirements, the acceleration part and / or the pressure distortion part are adjusted and step 4 is repeated. Specifically: When the pressure field does not meet the set requirements, adjust the opening size, opening form or opening position of the pressure distortion plate, and re-conduct the wind blowing test on the scaled model.

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