High turbulence level pressure distortion simulation method based on acceleration principle

Abstract

The invention provides a high turbulence level pressure distortion simulation method based on an acceleration principle. The method comprises the following steps: step 1, carrying out acceleration part design and pressure distortion part design; 2, the acceleration part and the pressure distortion part are combined into a whole, and numerical simulation is carried out; 3, when the pressure field of numerical simulation meets the set requirement, the scaling model part is machined, and the step 4 is executed; when the pressure field of the numerical simulation does not meet the set requirement, the pressure distortion part is adjusted according to the numerical simulation result, and the second step is repeated; 4, carrying out a blowing test on the scaling model part, and obtaining parameters of an outlet flow field of the scaling model part; 5, when the parameters of the outlet flow field of the scaling model meet the set requirements, determining the real size of the pressure distortion simulation device according to the size of the scaling model; and when the parameters of the outlet flow field of the scaling model do not meet the set requirements, the acceleration part and / or the pressure distortion part are / is adjusted, and the fourth step is repeated.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengines, and in particular to a high turbulence pressure distortion simulation method based on the acceleration principle. Background Art

[0002] Since the inlet / engine compatibility issue attracted international attention in the 1960s, countries have paid more and more attention to the simulation research of engine inlet flow field distortion. Due to the high cost of inlet and engine joint testing, various inlet distortion simulation technologies have emerged, which can generate flow fields consistent with the inlet outlet distortion effect.

[0003] There are many types of engine inlet flow field simulation devices, such as grid distortion simulators, random frequency simulators, orifice simulators, plug-in spoilers, etc. Different types of distortion devices have their own characteristics. Among them, the orifice simulator is a distortion test device recommended in general specifications because it is simple, effective and economical. However, compared with the steady-state distortion index (circumferential total pressure unevenness), the dynamic distortion index (turbulence) generated by the orifice simulator is generally lower, and the dynamic-to-steady ratio is generally 1:8 to 1:5, and it is impossible to simulate the steady-state distortion index and dynamic distortion index of the inlet outlet flow field at the same time. Summary of the invention

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

[0005] The present invention provides the following technical solutions: a high turbulence pressure distortion simulation method based on the acceleration principle, comprising the following steps: step one, designing an acceleration part and a pressure distortion part; step two, combining the acceleration part and the pressure distortion part into a whole and performing numerical simulation; step three, when the pressure field of the numerical simulation meets the set requirements, processing the scaled model and entering step four; when the pressure field of the numerical simulation does not meet the set requirements, adjusting the pressure distortion part according to the numerical simulation results and repeating step two; step four, conducting a blowing test on the scaled model to obtain the parameters of the outlet flow field of the scaled model; step five, when the parameters of the outlet flow field of the scaled model meet the set requirements, determining the actual size of the pressure distortion simulation device 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, adjusting the acceleration part and / or the pressure distortion part and repeating step four.

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

[0007] Furthermore, the shapes of the acceleration block include circular ring, crescent and straight plate.

[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; setting a spoiler baffle in an area less than the set multiple average pressure curve; opening holes in the spoiler baffle according to the pressure gradient; and creating a three-dimensional model of the pressure distortion plate.

[0009] Furthermore, 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.

[0010] Furthermore, 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.

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

[0012] Furthermore, 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 four is repeated. Specifically, when the turbulence does not meet the set requirements, the acceleration blocks of different areas and the acceleration sections of different lengths are replaced and the blowing test of the scaled model is carried out again.

[0013] Furthermore, 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 four is repeated. Specifically, when the pressure field does not meet the set requirements, the hole size, hole form or hole position of the pressure distortion plate is adjusted, and the blowing test of the scaled model is carried out again.

[0014] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above-mentioned technical solutions adopted by the present invention include at least the following: the present invention can improve the turbulence generated in the pressure distortion simulation method based on the orifice simulator, so that the surface average turbulence generated by the pressure distortion simulation device reaches more than 5%, and the ratio of dynamic distortion to steady-state distortion reaches 1:2 to 3:2, making it possible to simultaneously simulate the steady-state distortion index and dynamic distortion index of the inlet outlet pressure distortion flow field. 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 ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 Design a flow chart for a high turbulence simulation device based on the acceleration principle; Figure 2 is a schematic diagram of the target map; Figure 3 It is a schematic diagram of the acceleration block; Figure 4 This is a schematic diagram of the acceleration section of 0.4 times the pipe diameter; Figure 5 This is a schematic diagram of the acceleration section of 0.8 times the pipe diameter; Figure 6 It is a schematic diagram of isobar distribution; Figure 7 It is a schematic diagram of 0.98 times the average pressure curve; Figure 8 To complete the schematic diagram of the opening in the baffle area; Fig. 9 Schematic diagram of the model. DETAILED DESCRIPTION

[0017] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0018] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents 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 methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0019] like Figure 1 As shown, an embodiment of the present invention provides a high turbulence pressure distortion simulation method based on the acceleration principle, comprising the following steps: 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-through 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, determine the actual size of the pressure distortion simulation device 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, adjust the acceleration part and / or the pressure distortion part and repeat step 4.

[0020] The high turbulence pressure distortion simulation method of the present invention is based on the acceleration principle. Through the action of the acceleration plate and the acceleration section, the airflow in front of the pressure distortion plate is accelerated to impact the pressure distortion simulation plate, and high turbulence is produced behind the pressure distortion simulation plate, thereby realizing simultaneous simulation of turbulence and circumferential pressure distortion index.

[0021] The acceleration part design includes: Design multiple groups of acceleration blocks according to the pipeline area of ​​0.5~0.9 times of the pressure distortion simulation device; Design multiple groups of acceleration sections according to 0.4~2.0 times the pipe diameter of the pressure distortion simulation device; Create 3D models of acceleration blocks and acceleration sections.

[0022] 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.

[0023] The design of pressure distortion part includes: Determine the pressure field distribution according to the target map; Generate a set multiple average pressure curve based on the pressure field distribution; A spoiler baffle is provided in the area within the average pressure curve which is less than a set multiple; Holes are opened on the spoiler baffle according to the pressure gradient; Create a 3D model of a pressure distortion plate.

[0024] Furthermore, 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.

[0025] In the embodiment 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.

[0026] It should be noted 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.

[0027] 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.

[0028] 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.

[0029] The following is described with a specific embodiment: A. Design acceleration part; 1) Target map such as Figure 2 As shown, the target operating condition AIP Mach number is 0.2, turbulence is 2.1%, and circumferential non-uniformity is 3.5%; 2) Design the accelerator block. Considering the target operating condition AIP Mach number is small, only 0.2, three accelerator blocks are designed according to 0.6 times the pipeline area, 0.7 times the pipeline area and 0.8 times the pipeline area. Considering the pipeline cross section is circular, a circular throttling accelerator block is designed. The three designed accelerator blocks are as follows: Figure 3 As shown, Figure 3 From left to right in the figure are the 60% pipeline area schematic diagram, the 70% pipeline area schematic diagram and the 80% pipeline area schematic diagram; 3) Design the acceleration section. Considering that the target operating condition AIP Mach number is small, only 0.2, the acceleration section length is designed as 0.4 times the pipeline diameter and 0.8 times the pipeline diameter, respectively, for a total of 2 groups. Through combination, 3 groups of acceleration sections can be formed, 0.4 times the pipeline diameter, 0.8 times the pipeline diameter and 1.2 times the pipeline diameter, for a total of 3 groups. The designed 2 acceleration sections are as follows: Figure 4 and Figure 5 As shown, Figure 4 Schematic diagram of the acceleration section of 0.4 times the pipe diameter and Figure 5 This is a schematic diagram of the acceleration section of 0.8 times the pipe diameter; 4) Create three-dimensional model entities of acceleration blocks and acceleration sections.

[0030] B. Design pressure distortion part; 1) Clarify the target map pressure field distribution (see Figure 2 ); 2) Generate isobars according to the target pressure field distribution (see Figure 6 ), and extract 0.98 times the average pressure curve data; 3) With 0.98 times the average pressure curve as the boundary, the area with a pressure less than 0.98 times is equipped with a spoiler, and the rest of the area is not equipped (see Figure 7 ); 4) In the baffle area, draw pressure lines of 0.94 times the average pressure and 0.96 times the average pressure. According to the pressure gradient, the higher the pressure, the more and larger the holes are, while the lower the pressure, the fewer and smaller the holes are (see Figure 8); 5) Create a three-dimensional model entity of the pressure distortion plate.

[0031] C. Combine the acceleration part and the pressure distortion part into a whole, with the acceleration part located at the front end and the pressure distortion part located at the back end, carry out overall numerical simulation, and compare the numerical simulation outlet flow field with the target map; D. Using numerical simulation, after two rounds of iterations, the opening form and size in the baffle area were adjusted. The pressure spectrum of the outlet flow field was similar to the target spectrum. At the same time, the circumferential pressure distortion index was 1.4 times that of the target spectrum. The pressure distortion part met the requirements. E. Processing scaled model parts (see Fig. 9 ), the diameter of the scaled model is 200mm; F. Carry out a blow test on a scaled model to obtain the outlet pressure distribution, turbulence, and circumferential pressure distortion index of the model. During the test, the acceleration block and the acceleration section were adjusted several times. After using an acceleration block with an area of ​​70% of the pipeline and an acceleration section with a length of 0.4 times the pipeline diameter, the turbulence at the outlet of the device reached 1.9%, meeting the target turbulence requirement. G. In the blown air test of the scaled model, the pressure distortion plate was fine-tuned, and the final circumferential pressure unevenness was 3.7%, and the comprehensive distortion index was 5.6%; H. The curve size of the pressure distortion plate was tested using a three-coordinate measuring instrument, and the pressure distortion plate, acceleration block and acceleration section were enlarged in proportion to complete the high turbulence pressure distortion simulation design based on the acceleration principle.

[0032] The above is only a specific implementation 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 a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on 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 four is repeated.

2. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 1 is characterized in that: The acceleration part design includes: Design multiple groups of acceleration blocks according to the pipeline area of ​​0.5~0.9 times of the pressure distortion simulation device; Design multiple groups of acceleration sections according to 0.4~2.0 times the pipe diameter of the pressure distortion simulation device; Create 3D models of acceleration blocks and acceleration sections.

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

4. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 2 is characterized in that: The design of pressure distortion part includes: Determine the pressure field distribution according to the target map; Generate a set multiple average pressure curve based on the pressure field distribution; A spoiler baffle is provided in the area within the average pressure curve which is less than a set multiple; Opening holes on the spoiler baffle according to the pressure gradient; Create a 3D model of a pressure distortion plate.

5. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 4 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.

6. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 5 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.

7. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 6 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.

8. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 7 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.

9. The high turbulence pressure distortion simulation method based on the acceleration principle according to claim 7 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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