Stream-thermosetting coupling transient gap modeling method for cross-time-scale information interaction

Abstract

The invention provides a fluid-thermosetting coupling transient gap modeling method for cross-time-scale information interaction, and belongs to the field of aero-engine simulation computation.The method comprises the steps that a solid domain finite element mesh model of a structural member is constructed; establishing a one-dimensional fluid domain air system flow path model according to the structural form of the structural member and an air flow path in the structural member, obtaining a sealing gap and a fluid-solid domain boundary point temperature, carrying out air system flow path calculation, and obtaining an air system node parameter of a first transient process t1; and solid domain temperature field calculation is carried out based on the solid domain finite element mesh model and the air system node parameters, the solid domain mesh node temperature is obtained, solid domain deformation calculation is further carried out based on the solid domain mesh node temperature, and the wall surface temperature and the sealing gap of the second transient process t2 are obtained. And the fluid domain and the solid domain are subjected to transient calculation according to respective time steps, and when the first transient process t1 is equal to the second transient process t2, the fluid domain and the solid domain are subjected to information interaction once.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aero-engine simulation calculation, and particularly relates to a flow-thermal-solid coupling transient gap modeling method of cross-time scale information interaction. BACKGROUND

[0002] The finite element simulation modeling method of flow-thermal-solid multi-physical field coupling plays an important role in improving the calculation accuracy of structural deformation and temperature field. For the calculation of the labyrinth seal gap of the rotor-stator seal of the aero-engine in the form of the labyrinth honeycomb, in the strong coupling transient calculation process of the air system flow path parameters, the rotor-stator structure temperature field and the rotor-stator deformation, the temperature response time of the air system flow path fluid domain cavity is very short, generally in the order of 10 -1 s; the temperature field response time obtained by the structure thermal analysis is generally in the order of 10 2 s; the structure thermal deformation response time of the solid domain is about 10 2 s. If the seal gap value calculated by the structure thermal deformation of the solid domain is to be established in a transient strong coupling relationship with the fluid domain parameter calculated by the air system flow path, the time scales of the two are different by three to four orders of magnitude. Therefore, when modeling the gap calculation of the multi-physical field coupling transient thermal deformation, the problem of cross-time scale information transmission of the flow-thermal-solid multi-physical field needs to be considered.

[0003] At present, when dealing with the multi-physical field coupling calculation based on the commercial finite element calculation software such as Ansys, in order to meet the general needs of different users, the real-time interactive information is adopted in a single step between the fluid domain and the solid domain. When modeling the transient gap, two-dimensional or three-dimensional models of the air system fluid domain and the structure solid domain should be established.

[0004] However, the existing transient gap modeling process has the following disadvantages:

[0005] 1) Two-dimensional or three-dimensional modeling of the fluid domain and coupling calculation with the solid domain, in order to ensure the transient calculation accuracy, the time step is set to be small according to the response time of the fluid domain, and the amount of finite element grid is large. If the information transmission of the gap to the air system fluid domain is to be realized, the structure solid domain modeling should have the adaptive grid capability to solve the problem of grid amount change when the structure deformation is large, resulting in long transient calculation time and low calculation efficiency;

[0006] 2) The modeling process does not support the interactive coupling of the three physical fields of aerodynamics-thermal analysis-deformation, and only allows two of them to transmit information to each other at the same time, which is not suitable for the needs of transient gap simulation;

[0007] 3) The coupling influence of the gap information obtained by the structure deformation calculation on the air system throttling characteristics is easy to cause the divergence of the fluid domain calculation, resulting in the calculation results unable to converge and the need to repeat the modeling. SUMMARY

[0008] The purpose of this application is to provide a method for modeling transient gaps in fluid-thermal-structure coupling with cross-timescale information interaction, in order to solve or mitigate at least one of the problems in the background art.

[0009] The technical solution of this application is: a method for modeling transient gaps in fluid-thermal-structure coupling with cross-timescale information interaction, comprising:

[0010] S10, construct the solid domain finite element mesh model of the structural component for solid domain temperature field calculation and deformation calculation;

[0011] S20. Based on the structural form of the structural component and the air flow path inside it, a one-dimensional fluid domain air system flow path model is established to obtain the sealing gap and the temperature of the fluid-solid domain boundary point. The fluid domain air system flow path model performs air system flow path calculation based on the sealing gap and the temperature of the fluid-solid domain boundary point to obtain the air system node parameters of the first transient process t1.

[0012] S30, based on the solid domain finite element mesh model and air system node parameters, perform solid domain temperature field calculation to obtain solid domain mesh node temperature, and further perform solid domain deformation calculation based on the solid domain finite element mesh model and solid domain mesh node temperature to obtain the wall temperature and sealing gap of the second transient process t2;

[0013] S40, the fluid domain and the solid domain perform transient calculations according to their respective time steps. When the first transient process t1 is equal to the second transient process t2, the fluid domain and the solid domain perform an information exchange. The information relationships transmitted in the exchange include: the air system node parameters calculated in the fluid domain are transmitted to the temperature boundary of the solid domain; the wall temperature calculated in the temperature field of the solid domain is transmitted to the boundary of the fluid domain, and at the same time, the sealing gap calculated in the deformation of the solid domain is transmitted to the gap boundary of the fluid domain; the temperature of the grid node in the temperature field calculation in the solid domain is transmitted synchronously to the deformation calculation.

[0014] Furthermore, step S20 specifically includes:

[0015] The initial sealing gap and initial aerodynamic parameters are obtained and then transferred to the one-dimensional fluid domain air system flow path model to obtain the initial values ​​of the one-dimensional fluid domain at the initial time of the first transient process t1.

[0016] The temperature of the fluid-solid boundary point at the initial moment of the first transient process t1 is obtained, and the temperature of the fluid-solid boundary point is transferred to the one-dimensional air system flow path model. The nodal parameters of the air system are calculated through the one-dimensional air system flow path model.

[0017] Determine whether all nodal parameters of the air system have converged. If all nodal parameters have converged, end the flow path calculation of the one-dimensional air system. If not, continue the calculation until all nodal parameters have converged.

[0018] When all the node parameters of the air system converge, the flow path calculation of the one-dimensional air system for one time step is completed, and the node parameters of the air system are output, thereby obtaining the node parameters of the air system at the end of the first transient process t1.

[0019] Furthermore, the initial sealing gap is obtained through a solid domain finite element mesh model of the structural component.

[0020] Furthermore, the node parameters include mass flow rate m, heat transfer coefficient h, and fluid temperature T.

[0021] Furthermore, step S30 specifically includes:

[0022] Based on the solid domain finite element mesh model, the finite element mesh and boundary information are obtained. The heat transfer boundary information and the air system node parameters at the initial time of the second transient process t2 are loaded sequentially. The unsteady heat conduction is calculated, the mesh point temperature of the solid domain temperature field is solved, and the wall temperature at the end of the second transient process t2 is output.

[0023] Based on the same solid domain finite element mesh model, by reading in the finite element mesh and boundary information, displacement constraints and mesh node temperatures calculated from the solid domain temperature field are applied sequentially, the total stiffness matrix is ​​calculated, the solid domain mesh node displacements are solved, and the sealing gap δ at the end of the second transient process t2 is output by selecting the node displacement at the sealing gap location, thus completing the two-dimensional solid domain deformation calculation.

[0024] Furthermore, the time step between the initial and final moments of the first transient process t1 is the first time step Δt1, and the time step between the initial and final moments of the second transient process t2 is the second time step Δt2, where Δt2 = N * Δt1, N is a positive integer and N ≥ 2.

[0025] The proposed method for modeling transient gaps in fluid-thermal-structure coupling based on cross-timescale information interaction has the following advantages:

[0026] 1) Using a one-dimensional fluid domain air system calculation model to calculate the air system flow path can significantly reduce the amount of calculation while meeting the calculation accuracy requirements, reduce the risk of repeated modeling due to non-convergence of the fluid domain, and improve the calculation efficiency.

[0027] 2) The solid domain and fluid domain are calculated according to their respective time steps, which solves the problem of inconsistent response time and improves computational efficiency;

[0028] 3) Under different time step conditions in the fluid and solid domains, the content and criteria for information interaction were proposed, realizing cross-time scale information interaction and improving the accuracy of transient gap calculation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0030] Figure 1 This is a schematic diagram of the transient gap modeling method for cross-timescale information interaction in this application involving fluid-thermal-structure coupling. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0032] To overcome the problems encountered in the modeling of transient gaps in the turbine-stator sealing of aero-engines in the form of a honeycomb structure, this application proposes a fluid-thermal-structure coupling transient gap modeling method with cross-timescale information interaction.

[0033] like Figure 1 As shown, the fluid-thermal-structure coupling transient gap modeling method for cross-timescale information interaction provided in this application includes the following steps:

[0034] S10: Construct a solid domain finite element mesh model of the structural component for solid domain temperature field calculation and deformation calculation. The same solid domain finite element mesh model is used for both solid domain temperature field calculation and deformation calculation.

[0035] This embodiment of the application uses a rotor-stator sealing structure in the form of a honeycomb tooth pattern from an aero-engine as an example for illustration. This structural component typically includes inner and outer casings that form the airflow path, rotor-stator blades through which air flows, and honeycomb tooth structures for sealing. Therefore, the finite element mesh model of the solid domain of the structural component constructed in this step is a finite element model composed of the inner and outer casings, rotor-stator blades, and honeycomb tooth structures.

[0036] S20. Based on the structural form of the structural component and its internal air flow path, establish a one-dimensional fluid domain air system flow path model, obtain the sealing gap and the temperature of the fluid-solid domain boundary point, and perform air system flow path calculation based on the sealing gap and the temperature of the fluid-solid domain boundary point to obtain the air system node parameters of the first transient process t1.

[0037] Specifically, step S20 includes:

[0038] S21, obtain the initial sealing gap δ and initial aerodynamic parameters, and transfer the initial sealing gap δ and initial aerodynamic parameters to the one-dimensional fluid domain air system flow path model to obtain the initial value of the one-dimensional fluid domain at the initial time of the first transient process t1.

[0039] In some embodiments of this application, the initial sealing gap δ is obtained through a solid domain finite element mesh model of the structural component.

[0040] S22, obtain the temperature of the fluid-solid boundary point at the initial moment of the first transient process t1, transfer the temperature of the fluid-solid boundary point to the one-dimensional air system flow path model, and calculate the nodal parameters of the air system through the one-dimensional air system flow path model. The nodal parameters of the air system include mass flow rate q, heat transfer coefficient h and fluid temperature T.

[0041] S23. Determine whether all node parameters of the air system have converged. If all have converged, end the flow path calculation of the one-dimensional air system. If not, continue the calculation until all node parameters have converged.

[0042] S24. When all the node parameters of the air system converge, the flow path calculation of the one-dimensional air system for one time step is completed. At this time, the node parameters of the air system are output, thus obtaining the node parameters of the air system at the end of the first transient process t1.

[0043] In this application, the response time of the fluid domain air system calculation is relatively fast. The time step between the initial and final moments of the first transient process t1 is the first time step Δt1, and the interval of the first time step Δt1 is usually small. For example, the first time step Δt1 can be 10 ms.

[0044] S30. Based on the solid domain finite element mesh model established in step S10 and the air system node parameters obtained in step S20, the solid domain temperature field is calculated to obtain the solid domain mesh node temperature. Based on the solid domain finite element mesh model and the solid domain mesh node temperature, the solid domain deformation is calculated to obtain the wall temperature and sealing gap of the second transient process t2.

[0045] Specifically, step S30 includes:

[0046] S31. Based on the solid domain finite element mesh model in step S10, obtain the finite element mesh and boundary information, load the heat transfer boundary information and the heat transfer coefficient h and fluid temperature T in the air system node parameters at the initial time of the second transient process t2 in sequence, calculate the unsteady heat conduction, solve the mesh point temperature of the solid domain temperature field, and output the wall temperature at the end of the second transient process t2.

[0047] S32, based on the same solid domain finite element mesh model, by reading in the finite element mesh and boundary information, sequentially loading displacement constraints and the mesh node temperature calculation results of the solid domain temperature field, performing total stiffness matrix calculation, solving the solid domain mesh node displacement, and by selecting the node displacement at the sealing gap position, outputting the sealing gap δ at the end of the second transient process t2, thus completing the two-dimensional solid domain deformation calculation.

[0048] In the process of calculating the temperature field and deformation in the two-dimensional solid domain, the wall temperature and sealing gap δ can be output simultaneously at the end of the second transient process t2, that is, the temperature field and deformation in the two-dimensional solid domain are calculated with the same step size.

[0049] In this application, the thermal analysis response time of the temperature field in the solid domain is relatively slow. The time step between the initial and final moments of the second transient process t2 is the second time step Δt2. The interval of the second time step Δt2 is usually relatively large, and it is an integer multiple of the first time step Δt1, i.e., Δt2 = N * Δt1, where N is a positive integer, usually greater than or equal to 2. For example, the second time step Δt2 can be 30 ms.

[0050] S40, the fluid domain and solid domain perform transient calculations according to their respective time steps. When the first transient process t1 is equal to the second transient process t2, the fluid domain and solid domain perform an information exchange. The information exchanged includes: the air system node parameters (i.e., mass flow rate q, heat transfer coefficient h, and fluid temperature T) calculated in the fluid domain are transferred to the temperature boundary of the solid domain; the wall temperature calculated in the temperature field of the solid domain is transferred to the boundary of the fluid domain, and at the same time, the sealing gap δ calculated in the deformation of the solid domain is transferred to the gap boundary of the fluid domain; the grid node temperature calculated in the temperature field of the solid domain is synchronously transferred to the deformation calculation.

[0051] The proposed method for modeling transient gaps in fluid-thermal-structure coupling based on cross-timescale information interaction has the following advantages:

[0052] 1) Using a one-dimensional fluid domain air system calculation model to calculate the air system flow path can significantly reduce the amount of calculation while meeting the calculation accuracy requirements, reduce the risk of repeated modeling due to non-convergence of the fluid domain, and improve the calculation efficiency.

[0053] 2) The solid domain and fluid domain are calculated according to their respective time steps, which solves the problem of inconsistent response time and improves computational efficiency;

[0054] 3) Under different time step conditions in the fluid and solid domains, the content and criteria for information interaction were proposed, realizing cross-time scale information interaction and improving the accuracy of transient gap calculation.

[0055] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for modeling transient gaps in fluid-thermal-structure coupling with cross-timescale information interaction, characterized in that, include: S10, construct the solid domain finite element mesh model of the structural component for solid domain temperature field calculation and deformation calculation; S20. Based on the structural form of the structural component and the air flow path inside it, a one-dimensional fluid domain air system flow path model is established to obtain the sealing gap and the temperature of the fluid-solid domain boundary point. The fluid domain air system flow path model performs air system flow path calculation based on the sealing gap and the temperature of the fluid-solid domain boundary point to obtain the air system node parameters of the first transient process t1. S30, based on the solid domain finite element mesh model and air system node parameters, perform solid domain temperature field calculation to obtain solid domain mesh node temperature, and further perform solid domain deformation calculation based on the solid domain finite element mesh model and solid domain mesh node temperature to obtain the wall temperature and sealing gap of the second transient process t2; S40, the fluid domain and the solid domain perform transient calculations according to their respective time steps. When the first transient process t1 is equal to the second transient process t2, the fluid domain and the solid domain perform an information exchange. The information relationship transmitted in the exchange includes: the air system node parameters calculated by the fluid domain are transmitted to the temperature boundary of the solid domain. The wall temperature calculated in the solid domain temperature field is transferred to the boundary of the fluid domain, while the sealing gap calculated in the solid domain deformation is transferred to the gap boundary of the fluid domain; the temperature of the grid nodes in the solid domain temperature field calculation is transferred synchronously to the deformation calculation.

2. The method for modeling transient gaps in fluid-thermal-structure coupling with cross-timescale information interaction as described in claim 1, characterized in that, Step S20 specifically includes: The initial sealing gap and initial aerodynamic parameters are obtained and then transferred to the one-dimensional fluid domain air system flow path model to obtain the initial values ​​of the one-dimensional fluid domain at the initial time of the first transient process t1. The temperature of the fluid-solid boundary point at the initial moment of the first transient process t1 is obtained, and the temperature of the fluid-solid boundary point is transferred to the one-dimensional air system flow path model. The nodal parameters of the air system are calculated through the one-dimensional air system flow path model. Determine whether all nodal parameters of the air system have converged. If all nodal parameters have converged, end the flow path calculation of the one-dimensional air system. If not, continue the calculation until all nodal parameters have converged. When all the node parameters of the air system converge, the flow path calculation of the one-dimensional air system for one time step is completed, and the node parameters of the air system are output, thereby obtaining the node parameters of the air system at the end of the first transient process t1.

3. The method for modeling transient gaps in fluid-thermal-structure coupling with cross-timescale information interaction as described in claim 2, characterized in that, The initial sealing gap is obtained through a solid domain finite element mesh model of the structural component.

4. The method for modeling transient gaps in fluid-thermal-structure coupling with cross-timescale information interaction as described in claim 2, characterized in that, The node parameters include mass flow rate m, heat transfer coefficient h, and fluid temperature T.

5. The method for modeling transient gaps in fluid-thermal-structure coupling with cross-timescale information interaction as described in any one of claims 2 to 4, characterized in that, Step S30 specifically includes: Based on the solid domain finite element mesh model, the finite element mesh and boundary information are obtained. The heat transfer boundary information and the air system node parameters at the initial time of the second transient process t2 are loaded sequentially. The unsteady heat conduction is calculated, the mesh point temperature of the solid domain temperature field is solved, and the wall temperature at the end of the second transient process t2 is output. Based on the same solid domain finite element mesh model, by reading in the finite element mesh and boundary information, displacement constraints and mesh node temperatures calculated from the solid domain temperature field are applied sequentially, the total stiffness matrix is ​​calculated, the solid domain mesh node displacements are solved, and the sealing gap δ at the end of the second transient process t2 is output by selecting the node displacement at the sealing gap location, thus completing the two-dimensional solid domain deformation calculation.

6. The method for modeling transient gaps in fluid-thermal-structure coupling with cross-timescale information interaction as described in claim 5, characterized in that, The time step between the initial and final moments of the first transient process t1 is the first time step Δt1, and the time step between the initial and final moments of the second transient process t2 is the second time step Δt2, where Δt2 = N * Δt1, N is a positive integer and N ≥ 2.

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