Engine environment temperature virtual experiment method

Abstract

The invention discloses an engine environment temperature virtual test method. The method comprises the following steps: firstly, performing high and low temperature environment box simulation; comprehensive simulation of the product, the high and low temperature environment box and the medium is carried out; the high and low temperature environment box simulation specifically comprises the following steps of high and low temperature environment box key parameter extraction, model establishment and high and low temperature environment box simulation and optimization. According to the engine environment temperature virtual test method, on the basis of system steady-state temperature distribution, the heat exchange dynamic process of a product and the environment temperature is simulated through flow field-temperature-solid coupling simulation, the dynamic influence mechanism of the environment temperature and the medium temperature on all parts of the product is further studied, and the engine environment temperature virtual test result is obtained. The influence weights of the two temperatures on the product are explored, the environment-medium comprehensive high and low temperature test method is optimized, the product quality and the corresponding relation between the medium-environment temperature difference and the heat preservation duration are quantified, and the environment-medium comprehensive high and low temperature test method is optimized.

Description

Technical Field

[0001] The invention relates to the technical field of engine environmental testing, and in particular to a virtual testing method for engine environmental temperature. Background Art

[0002] Engine environmental testing simulates the actual working conditions of the engine in the test room, applies vibration, temperature, air pressure and other loads to the engine component products to evaluate the performance indicators of the products. It is an essential work before the product is installed in the engine and the aircraft is tested. When conducting online temperature tests, the product housing and internal components will be affected by the combined influence of the ambient temperature and the medium temperature. The current military standard for environmental testing has a general and broad provision for the insulation time of the environment-medium comprehensive high and low temperature test, without a specific time, which may lead to the risk of insufficient or lack of insulation time. Summary of the invention

[0003] The purpose of the present invention is to provide an engine ambient temperature virtual test method. In view of the problems existing in the prior art, based on the previous static temperature field simulation conclusion (that is, the medium temperature weight is greater than the ambient temperature), based on the steady-state temperature distribution of the system, through flow field-temperature-solid coupling simulation, the dynamic process of heat exchange between the product and the ambient temperature is simulated, and the dynamic influence mechanism of the ambient temperature and the medium temperature on each component of the product is further studied, the influence weight of the two temperatures on the product is explored, the environment-medium comprehensive high and low temperature test method is optimized, the corresponding relationship between product quality, medium-ambient temperature difference and insulation time is quantified, and the environment-medium comprehensive high and low temperature test method is optimized.

[0004] To achieve the above object, the present invention provides an engine ambient temperature virtual test method, comprising the following steps: S1, high and low temperature environment chamber simulation; S2, comprehensive simulation of products, high and low temperature environment chambers and media; S1 specifically includes the following steps: S11, extracting key parameters of the high and low temperature environment box and establishing a model, wherein the key parameters of the high and low temperature environment box include temperature, flow rate and heat exchange rate; S12. High and low temperature environment chamber simulation and optimization. Through mesh refinement and parameter adjustment, the problem of the simulation results of the environment chamber not being consistent with the actual situation is solved. The mesh refinement specifically increases the number of meshes to 10.43 million meshes and sets an expansion layer at the boundary of the high and low temperature environment chamber.

[0005] Preferably, in S1, the high and low temperature environment box is used to simulate the high and low temperature environment of the engine and verify the temperature resistance reliability of the product. The high and low temperature environment box includes a box body, a heating tube, a compressor, a fan, thermal insulation cotton and a low-temperature heat exchange tube.

[0006] Preferably, in S12, a high and low temperature environment box model is established and a preliminary simulation is performed based on the key parameters extracted from the real high and low temperature environment box, including the box body, low temperature heat exchange tubes, inlet and outlet, and the parameter indicators of the high and low temperature environment box are input into the simulation model for preliminary simulation.

[0007] Preferably, in S12, the simulation authenticity of the high and low temperature environment box is verified by a nine-point temperature measurement method, wherein the nine-point temperature measurement method is to take eight vertices of the high and low temperature environment box body and a point at the center of the box body as temperature measurement points, and requires that the temperature uniformity is not equal to 2°C.

[0008] Preferably, in S2, the relationship between the insulation time and the product quality and the temperature difference between the medium and the environment is obtained through comprehensive simulation of the product, the high and low temperature environment box and the medium.

[0009] Preferably, S2 specifically combines the product with the high and low temperature environment box on the basis that the temperature field and flow field simulation of the high and low temperature environment box are qualified, and at the same time adds inlet and outlet oil circuits for passing oil to the product.

[0010] Therefore, the present invention adopts the above-mentioned engine ambient temperature virtual test method, and the beneficial effects are as follows: (1) Based on the previous static temperature field simulation conclusion, that is, the medium temperature weight is greater than the ambient temperature, the present invention simulates the dynamic process of heat exchange between the product and the ambient temperature through flow field-temperature-solid coupling simulation based on the steady-state temperature distribution of the system.

[0011] (2) The method provided by the present invention further studies the dynamic influence mechanism of ambient temperature and medium temperature on various components of the product, and explores the influence weights of the two temperatures on the product.

[0012] (3) The present invention optimizes the environment-medium comprehensive high and low temperature test method, quantifies the corresponding relationship between product quality, medium-environment temperature difference and insulation time, and optimizes the environment-medium comprehensive high and low temperature test method.

[0013] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an overall flow chart of an embodiment of an engine ambient temperature virtual test method of the present invention; Figure 2 It is a schematic diagram of environmental chamber parameter conversion of an embodiment of an engine ambient temperature virtual test method of the present invention; Figure 3 It is a schematic diagram of modeling an environmental chamber of an embodiment of an engine ambient temperature virtual test method of the present invention; Figure 4It is a schematic diagram of the boundary conditions of an environmental chamber of an embodiment of an engine ambient temperature virtual test method of the present invention; Figure 5 It is a temperature distribution cloud diagram in an environmental box of an embodiment of an engine ambient temperature virtual test method of the present invention; Figure 6 It is a cloud diagram of air flow field distribution in an environmental box of an embodiment of an engine ambient temperature virtual test method of the present invention; Figure 7 It is a grid division diagram of an embodiment of an engine ambient temperature virtual test method of the present invention; Figure 8 It is a partial enlarged view of a grid of an embodiment of a virtual test method for engine ambient temperature of the present invention; Fig. 9 It is an iterative convergence curve diagram of an embodiment of an engine ambient temperature virtual test method of the present invention. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0016] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0017] The present invention achieves the above-mentioned goal in two steps. First, the simulation of the high and low temperature environmental chamber must be completed. The authenticity of the simulation of the high and low temperature environmental chamber is verified through the nine-point temperature measurement method and related requirements (8 vertices of the high and low temperature environmental chamber body and 1 point in the center of the box body are taken as temperature measurement points, and the temperature uniformity is required to be ≠2°C); the comprehensive simulation of the environmental chamber + product is completed, and the relationship between the insulation time and the product quality, and the medium-ambient temperature difference is obtained.

[0018] like Figure 1 As shown, a virtual test method for engine ambient temperature includes the following steps: S1, high and low temperature environment chamber simulation; The high and low temperature environmental chamber with settings ranging from -60℃ to 220℃ and an internal size of 1m×1m×1m is used to simulate the high and low temperature environment of the engine. It is a device to verify the temperature resistance and reliability of the product. The high and low temperature environmental chamber includes components such as the chamber body, heating pipes, compressors, fans, thermal insulation cotton and low-temperature heat exchange pipes to achieve heat generation, heat exchange, insulation and circulation during the operation of the environmental chamber.

[0019] S1 specifically includes the following steps: S11. Extraction of key parameters and model establishment based on a high and low temperature environment box with a temperature range of -60°C to 220°C and an internal size of 1m×1m×1m; In order to better realize the environmental chamber simulation, the equipment implementation status of the environmental chamber heating and cooling process and the insulation process is understood, and the key points are sorted out in combination with the simulation requirements, such as Figure 2 As shown in the figure, the main parameters required for the simulation are determined to be temperature, flow rate, heat transfer rate, etc., which correspond to the important functional components of the real environmental chamber, such as low-temperature heat exchange tubes, fans, and insulation cotton. The environmental chamber model established is as follows Figure 3 shown.

[0020] S12, -60℃ to 220℃, high and low temperature environmental chamber simulation and optimization with internal dimensions of 1m×1m×1m.

[0021] Preliminary Implementation of Environmental Simulation According to the key parameters extracted from the real high and low temperature environment box, the high and low temperature environment box model is established and preliminarily simulated. Figure 4 As shown, it mainly includes the box body, low-temperature heat exchange tubes, inlet and outlet, all of which are modeled 1:1 with the actual object. Subsequently, the various parameter indicators of the high and low temperature environment box are input into the simulation model, and a preliminary simulation is carried out.

[0022] The nine-point temperature measurement method is used to verify the authenticity of the high and low temperature environment chamber simulation. The nine-point temperature measurement method takes the eight vertices of the high and low temperature environment chamber and a point in the center of the chamber as temperature measurement points, and requires that the temperature uniformity is not equal to 2°C.

[0023] The preliminary simulation results are different from the actual operation of the environmental chamber. The temperature uniformity is poor, and the temperature deviation at different positions of the chamber is large. It does not meet the requirements of the nine-point temperature measurement method and needs to be modified.

[0024] like Figure 7 As shown in the figure, the high and low temperature environment chamber simulation optimization solves the problem that the simulation results of the environment chamber are inconsistent with the actual situation through mesh refinement and parameter adjustment, and improves the simulation confidence. The mesh refinement is specifically to increase the number of meshes from the previous 20,000 meshes to 10.43 million meshes, and set an expansion layer at the boundary of the high and low temperature environment chamber, such as Figure 8 As shown, to optimize boundary influence.

[0025] like Fig. 9As shown, the horizontal axis represents the number of iteration steps, and the vertical axis represents the residual value. The difference between two iterative calculation values ​​of a physical quantity is called the iterative residual of the physical quantity. The commonly monitored residual values ​​are the energy equation, momentum equation and continuity equation. The meaning of the iterative convergence curve is: when the residual reaches a certain set standard (such as 10 to the negative 3rd power), it can be considered that the iterative calculation has reached convergence. By adjusting the box inlet wind speed and heat exchange tube temperature settings, the temperature uniformity, flow field, and heat exchange rate in the temperature field are matched. The temperature of the environmental box is made uniform and stable, and the temperature deviation is 1.47°C, which is better than 2°C and meets the nine-point temperature measurement requirements.

[0026] S2, comprehensive simulation of products, high and low temperature environment chambers and media; Through comprehensive simulation of products, high and low temperature environmental chambers and media, the relationship between insulation time and product quality, and medium-ambient temperature difference is obtained. On the basis of qualified simulation of temperature field and flow field of high and low temperature environmental chambers, the product is combined with the high and low temperature environmental chamber, and inlet and outlet oil circuits are added to pass oil to the product (fuel with temperature).

[0027] The difficulty of the simulation algorithm is further increased, which is the coupling of flow field + solid + thermal simulation. During the simulation process, due to the simulation parameter setting and the selection of the flow field model algorithm, problems with load coupling occurred, mainly manifested as floating point errors or non-convergence. The faults were identified one by one, and multiple parties gathered wisdom to finally achieve the simulation results that met the test index requirements.

[0028] Fluid-solid-thermal coupling model establishment Considering the simple flow path of pump products and the medium flow field design, a fuel pump is selected as the product first, and then extended to typical regulator products. So far, the environmental chamber + product model has been established, and the internal medium flow path model has been established, and preliminary simulation can be continued in the future.

[0029] Therefore, the present invention adopts the above-mentioned engine ambient temperature virtual test method, completes the modeling simulation of the high and low temperature environmental chamber according to the test objectives and test technical requirements, and verifies and optimizes the simulation to meet the nine-point temperature measurement requirements; then, a comprehensive simulation of the environmental chamber + product is carried out, and the fluid-solid-temperature simulation coupling method is used to explore the influencing factors of the insulation time and steady-state temperature time in the two stages of the high and low temperature test, and quantify them.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A virtual test method for engine ambient temperature, characterized in that: The following steps are involved: S1, high and low temperature environment chamber simulation; S2, comprehensive simulation of products, high and low temperature environment chambers and media; S1 specifically includes the following steps: S11, extracting key parameters of the high and low temperature environment box and establishing a model, wherein the key parameters of the high and low temperature environment box include temperature, flow rate and heat exchange rate; S12. High and low temperature environment chamber simulation and optimization. Through mesh refinement and parameter adjustment, the problem of the simulation results of the environment chamber not being consistent with the actual situation is solved. The mesh refinement specifically increases the number of meshes to 10.43 million meshes and sets an expansion layer at the boundary of the high and low temperature environment chamber.

2. The engine ambient temperature virtual test method according to claim 1, characterized in that: In S1, the high and low temperature environment box is used to simulate the high and low temperature environment of the engine and verify the temperature resistance reliability of the product. The high and low temperature environment box includes a box body, a heating pipe, a compressor, a fan, thermal insulation cotton and a low-temperature heat exchange pipe.

3. The engine ambient temperature virtual test method according to claim 2, characterized in that: In S12, based on the key parameters extracted from the real high and low temperature environment box, a high and low temperature environment box model is established and a preliminary simulation is performed, including the box body, low temperature heat exchange tubes, inlet and outlet. The various parameter indicators of the high and low temperature environment box are input into the simulation model for preliminary simulation.

4. The engine ambient temperature virtual test method according to claim 3, characterized in that: In S12, the simulation authenticity of the high and low temperature environment box is verified by a nine-point temperature measurement method, wherein the nine-point temperature measurement method is to take eight vertices of the high and low temperature environment box body and a point at the center of the box body as temperature measurement points, and requires that the temperature uniformity is not equal to 2°C.

5. The engine ambient temperature virtual test method according to claim 4, characterized in that: In S2, through comprehensive simulation of products, high and low temperature environment chambers and media, the relationship between insulation time and product quality and medium-ambient temperature difference is obtained.

6. The engine ambient temperature virtual test method according to claim 5, characterized in that: S2 specifically combines the product with the high and low temperature environment chamber on the basis that the temperature field and flow field simulation of the high and low temperature environment chamber are qualified, and at the same time, inlet and outlet oil circuits are added to pass oil to the product.

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