Research And Development Of Fluid-Structure Interaction Numerical Simulation Program Based On Arbitrary-Lagrangian-Euler Finite Element Methood

The main structure of the sodium cooled fast reactor body is a pool structure,and its main container contains a large amount of liquid metal sodium.Due to the large size and thin wall characteristics of the main container of the fast reactor body,the shaking of liquid metal sodium is coupled with the vibration of the main container wall under earthquake conditions,which means the effect of fluid solid coupling is very significant.Therefore,in the seismic safety analysis of the fast reactor body,It is very important to study the liquid sloshing problem considering the fluid solid coupling effect.A large amount of theoretical research,experimental research,and numerical simulations have been conducted on the problem of liquid sloshing in containers.Early numerical simulations generally used Euler or Lagrangian methods,and grids could not track the movement of the liquid surface well.Some numerical simulations were also based on potential flow theory,which can better reflect the frequency characteristics,but had a large prediction error for wave height.The popular Arbitrary Lagrangian Euler(ALE)method in recent years can solve the above problems,However,further research is needed on the treatment of the fluid solid coupling interface.This article proposes a fluid structure interaction model and develops a numerical simulation program for fluid structure interaction based on the ALE finite element method.This program was primarily used for the calculation of liquid sloshing problems in fast reactors.The program body is divided into three parts,namely the structural program based on the Euler finite element method,the fluid program based on the ALE finite element method,and the fluid structure coupling program that combines the two.This paper first verifies the structural finite element program,Because the current commercial software has been able to simulate the motion response of the structure well,the structural finite element program is compared with the ANSYS APDL software.The comparison includes statics verification and dynamic verification.The dynamic verification is divided into force load verification and displacement load verification.The comparison results show that the difference between the calculation results of the two is small,The structural finite element program can accurately simulate the motion response of the structure under force and displacement loads.Next,this article conducted verification of the fluid finite element program and designed a shaking table liquid shaking test,The simulation results of the fluid finite element program were compared with the experimental results,and the comparison results showed that the fluid finite element program can better reflect the wave height of the liquid.Finally,this article conducted verification of the fluid-structure interaction program,which is divided into two parts,The first part compares the fluid-structure interaction program with some experimental results of Lu et al.on a 1/20 scale fast reactor body model.The comparison results show that the fluid-structure interaction program can effectively simulate the liquid sloshing problem of rigid structures.The second part designs a liquid sloshing model of flexible structures,and the results show that the fluid-structure interaction program can be used to calculate the liquid sloshing problem of flexible structures.This study provides a numerical simulation program for the study of fluid-structure interaction in the fast reactor body,which has important academic and engineering significance for the engineering design and safety evaluation of fast reactors.