Asynchronous coupling method for increasing electromagnetic-thermal-force multi-physical field simulation speed

Abstract

The invention discloses an asynchronous coupling method for improving the simulation speed of an electromagnetic-thermal-force multi-physical field, and mainly solves the problem that the simulation efficiency is influenced by additional calculation generated by adopting the same time step in the electromagnetic-thermal-force multi-physical field simulation. Comprising the following steps: 1) setting a total time step number, and starting stepping; 2) performing electromagnetic simulation on the current time step by using a finite element algorithm to obtain electromagnetic field distribution; 3) setting a time scale factor, judging whether the remainder of the time scale factor in the current time step is 0 or not, if so, performing thermal simulation and force simulation of the current time step by using a finite element algorithm, and performing electromagnetic simulation of the next time step after obtaining a deformation grid; otherwise, directly performing; and 4) completing simulation tasks of all time steps, and ending instantaneous electromagnetic-thermal-force multi-physics field simulation. According to the method, the calculation amount of heat and force simulation can be saved, and the efficiency of electromagnetic-heat-force multi-physical field simulation is effectively improved while the simulation precision is not influenced.

Description

Technical Field

[0001] The present invention belongs to the field of electrical technology and further relates to computational electromagnetics. Specifically, it is an asynchronous coupling method for improving the speed of electromagnetic-thermal-force multi-physics field simulation. The method can be used to improve the efficiency of electromagnetic-thermal-force multi-physics field simulation and promote the application of multi-physics field simulation technology in wireless communications, integrated circuits, microwave circuits, antenna design, precision guidance and other fields. Background Art

[0002] In the fields of wireless communication, integrated circuits, microwave circuits, antenna design, precision guidance, etc., with electromagnetic fields as the center, the coupling problem of multiple physical fields such as electromagnetic fields, temperature fields, and stress fields is becoming more and more prominent. The actual measurement of the above electromagnetic-thermal-force multi-physical field coupling problems has the disadvantages of high cost, long cycle, and the results are easily affected by the test environment. Therefore, electromagnetic-thermal-force multi-physics simulation technology has become a necessary means to study the effects of multiple physical fields.

[0003] The current mainstream transient electromagnetic-thermal-force multi-physics simulation is usually based on the time-domain finite element algorithm. In addition to spatial discretization of the computational domain, time discretization is also required during simulation. The mesh size used for spatial discretization and the time step used for time discretization determine the speed of the entire transient electromagnetic-thermal-force multi-physics simulation. In traditional transient electromagnetic-thermal-force multi-physics simulation methods, electromagnetic simulation, thermal simulation, and force simulation are usually based on synchronous coupling simulation technology, that is, electromagnetic simulation, thermal simulation, and force simulation uniformly use the same time step. Although this facilitates information transmission between different physical fields, it ignores the fact that the change speed of electromagnetic phenomena is much faster than that of thermal and force phenomena. Therefore, the time step required for electromagnetic simulation is much smaller than that required for thermal and force simulation.

[0004] Since the time step required for electromagnetic simulation is much smaller than that required for thermal and force simulation, the synchronous transient electromagnetic-thermal-force multi-physics simulation must use the small time step required for electromagnetic simulation, which will bring a large amount of unnecessary calculations to thermal and force simulation, affecting the overall simulation efficiency of transient electromagnetic-thermal-force multi-physics simulation. Therefore, it is urgent to study an asynchronous coupling technology that can be applied to different simulation requirements in multi-physics fields. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and propose an asynchronous coupling method for improving the speed of electromagnetic-thermal-force multi-physics field simulation, which mainly solves the problem that the same time step is used in electromagnetic-thermal-force multi-physics field simulation to generate extra calculations and affect the simulation efficiency. The present invention can ensure that the electromagnetic simulation and the thermal and force simulations each select a suitable time step according to their own physical field characteristics, the electromagnetic simulation uses a small time step, and the thermal and force simulations use a large time step, thereby saving the calculation amount of the thermal and force simulations and effectively improving the efficiency of the electromagnetic-thermal-force multi-physics field simulation.

[0006] The present invention achieves the above-mentioned purpose by the following specific steps:

[0007] (1) Set the total time step number of transient electromagnetic-thermal-mechanical multi-physics field simulation to N, and the time step of the current simulation is recorded as the i-th time step, i = 1, 2, ..., N; let i = 1 to start stepping;

[0008] (2) For the i-th time step, use the finite element algorithm to perform electromagnetic simulation to obtain the electromagnetic field distribution;

[0009] (3) Determine whether i%α is equal to 0, where % represents the modulo operation and α represents the time scale factor; if i%α is not equal to 0, directly execute step (4); otherwise, use the finite element algorithm to perform thermal simulation and force simulation at the current time step to obtain the geometric mesh after thermal deformation;

[0010] (4) Determine whether i is less than N. If so, set i=i+1 and return to step (2). Perform electromagnetic simulation for the next time step based on the geometric mesh after thermal deformation obtained by force simulation. Otherwise, continue to step (5).

[0011] (5) End the simulation process and complete the transient electromagnetic-thermal-mechanical multi-physics field simulation task.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] Traditional transient electromagnetic-thermal-force multi-physics field simulation is usually based on synchronous coupling simulation technology. While it facilitates information transmission between different physical fields, it also brings unnecessary calculations, affecting the simulation efficiency. The present invention takes into account the large difference between the changing speed of electromagnetic phenomena and the changing speed of thermal and force phenomena. On the premise of comprehensively considering the characteristics of electromagnetic, thermal and force themselves, an asynchronous coupling method is designed for multi-physics field simulation to ensure that electromagnetic simulation and thermal and force simulation can respectively use appropriate time steps, that is, electromagnetic simulation uses a small time step, and thermal and force simulation uses a large time step, thereby saving the calculation amount of thermal and force simulation, and effectively improving the efficiency of electromagnetic-thermal-force multi-physics field simulation as a whole without affecting the simulation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Flow chart for realizing the method of the present invention;

[0015] Figure 2 It is a schematic diagram of the structure of a high-power microwave irradiation filter in an embodiment of the present invention;

[0016] Figure 3 10 ns is a temperature distribution diagram of the filter surface in an embodiment of the present invention; wherein (a) is the temperature distribution of the filter surface at 10 ns obtained by using the method of the present invention, and (b) is the temperature distribution of the filter surface at 10 ns obtained without using the method of the present invention;

[0017] Figure 4 is the displacement distribution of the filter surface in the embodiment of the present invention; wherein (a) is the displacement distribution of the filter surface obtained by using the method of the present invention, and (b) is the displacement distribution of the filter surface obtained without using the method of the present invention; DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0019] Example 1: Reference Figure 1 The present invention proposes an asynchronous coupling method for improving the simulation speed of electromagnetic-thermal-mechanical multi-physics fields, and the implementation steps are as follows:

[0020] Step 1. Set the total time step number of transient electromagnetic-thermal-mechanical multi-physics simulation to N, and the time step of the current simulation is recorded as the i-th time step, i = 1, 2, ..., N; set i = 1 to start stepping;

[0021] Step 2. For the i-th time step, use the finite element algorithm to perform electromagnetic simulation to obtain the electromagnetic field distribution;

[0022] Step 3. Determine whether i%α is equal to 0, where % represents the modulo operation and α represents the time scale factor; if i%α is not equal to 0, directly execute step 4; otherwise, use the finite element algorithm to perform thermal simulation and force simulation at the current time step to obtain the geometric mesh after thermal deformation.

[0023] The time scale factor is used to make the time step of thermal and force simulation reach α times of the time step of electromagnetic simulation, reducing the number of time iterations of thermal and force simulation. This embodiment uses a value within 500 for the time scale factor. When the finite element algorithm is used to perform thermal simulation and force simulation in the current time step, the loss power density transmitted from the electromagnetic simulation to the thermal simulation is the average value of the previous α time steps.

[0024] Step 4. Determine whether i is less than N. If so, set i=i+1 and return to step 2. Perform electromagnetic simulation for the next time step based on the geometric mesh after thermal deformation obtained by force simulation. Otherwise, continue to step 5.

[0025] Step 5. End the simulation process and complete the transient electromagnetic-thermal-mechanical multi-physics field simulation task.

[0026] Embodiment 2: The overall implementation steps of the present invention are the same as those of Embodiment 1. Now, a specific example is given to further describe the time scale factor designed in the present invention in detail:

[0027] Determine whether i%α is equal to 0, where the '%' symbol indicates a modulo operation, α represents a time scale factor, and this embodiment preferably uses α=500; if i%α is not equal to 0, then directly skip the subsequent thermal simulation and force simulation, and directly perform the electromagnetic simulation of the next time step; if i%α is equal to 0, then use the finite element algorithm to perform the thermal simulation and force simulation of the current time step, and note that at this time, the loss power density transmitted by the electromagnetic simulation to the thermal simulation takes the average value of the previous α time steps; after completing the thermal simulation and force simulation of the current time step, obtain the geometric mesh after thermal deformation. In this way, it can be ensured that the time step of the thermal and force simulation is α times the time step of the electromagnetic simulation, thereby reducing the number of time iterations of the thermal and force simulations and improving the efficiency of transient electromagnetic-thermal-force multi-physics field simulation.

[0028] The effect of the present invention is further described below in conjunction with simulation experiments.

[0029] In this experiment, the asynchronous coupling method proposed by the present invention for improving the simulation speed of transient electromagnetic-thermal-mechanical multi-physics fields is used and not used. Figure 2 The electromagnetic-thermal-mechanical multi-physics field simulation is performed on the high-power microwave irradiation filter structure problem shown, and the calculation time of the two is compared to verify the effectiveness of the present invention.

[0030] In this example, the high-power microwave irradiation direction is along the -z direction, the polarization direction is the +x direction, the amplitude is 1MV / m, and the frequency is 4GHz. Figure 3 (a) and (b) in the figure respectively show the temperature distribution of the filter surface at 10ns obtained by using and not using the method of the present invention, and the two are completely consistent. Figure 4 (a) and (b) in the figure respectively show the displacement distribution of the filter surface obtained by using and not using the method of the present invention, and the two are completely consistent. It can be seen that the method of the present invention does not affect the simulation accuracy; at the same time, the calculation time of the present invention in this example is 10342 seconds, while the calculation time of not using the present invention is 13523 seconds, which proves that the present invention can effectively improve the efficiency of electromagnetic-thermal-mechanical multi-physics field simulation.

[0031] The above experimental analysis proves the correctness and effectiveness of the method proposed in the present invention.

[0032] Parts of the present invention that are not described in detail belong to common knowledge among those skilled in the art.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Obviously, for professionals in this field, after understanding the content and principles of the present invention, they may make various modifications and changes in form and details without departing from the principles and structures of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. An asynchronous coupling method for improving the simulation speed of electromagnetic-thermal-mechanical multi-physics fields, characterized in that: The steps include: (1) Set the total time step number of transient electromagnetic-thermal-mechanical multi-physics field simulation to N, and the time step of the current simulation is recorded as the i-th time step, i = 1, 2, ..., N; let i = 1 to start stepping; (2) For the i-th time step, use the finite element algorithm to perform electromagnetic simulation to obtain the electromagnetic field distribution; (3) Determine whether i%α is equal to 0, where % represents the modulo operation and α represents the time scale factor; If i%α is not equal to 0, then directly execute step (4); otherwise, use the finite element algorithm to perform thermal simulation and force simulation at the current time step to obtain the geometric mesh after thermal deformation; (4) Determine whether i is less than N. If so, set i=i+1 and return to step (2). Perform electromagnetic simulation for the next time step based on the geometric mesh after thermal deformation obtained by force simulation. Otherwise, continue to step (5). (5) End the simulation process and complete the transient electromagnetic-thermal-mechanical multi-physics field simulation task.

2. The method according to claim 1, characterized in that: The time scale factor in step (3) is used to make the time step of thermal and force simulation reach α times the time step of electromagnetic simulation, thereby reducing the number of time iterations of thermal and force simulation.

3. The method according to claim 2, characterized in that: The time scale factor α adopts a value within 500.

4. The method according to claim 1, characterized in that: When the finite element algorithm is used to perform thermal simulation and force simulation in the current time step in step (3), the loss power density transmitted from the electromagnetic simulation to the thermal simulation is taken as the average value of the previous α time steps.

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