Numerical Simulation Of Interacting Acoustic-Elastic Waves With Unstructured Finite Volume Time Domain Method

The interacting of the vibration of the structure and the sound field exist in the domain of auto cabin, spacecraft and architectural acoustic and so on. In this paper, one unstructured finite volume time domain method is newly applied to the Acoustic-Elastic interacting problems, the main content are as follows:1. The Acoustic-Elastic interacting is a kind of couple between two medium which is the presupposition of this study. The importation of the multi-zone unstructured mix-grid data in pre-posting is mainly settled in this paper.In this paper, CGNS-API is called by the pre-posting of GTEA to read the grid data. GTEA program would be able to find the corresponding points in the different neighboring zone using Hash searching method to form the connecting interface between two zones. Importation of three dimensional unstructured multi-domain grid data means a lot. The pre-posting process brought forward in this paper makes the simulation of acoustic-elastic coupled problem become possible which also ensured the continuities of the pressure, velocity and flux of the fluid-solid interface.2. One unstructured finite volume time domain method is presented to solve the Acoustic-Elastic problems.Using the FORTRAN 90 language, stress wave propagation of elastic structure and sound propagation of flow field are simulated and the interacting boundary condition is also dealt with. With the acoustic wave equation and the mixed displacement-stress elastic wave propagation being separately applied to the sound field and the structure, the numerical simulation method is deduced where the time dispersed by the two-order center scheme and the space by the finite volume method. Using the Euler explicit based on the dynamic equilibrium equations and the Huke law and constructive correlation of them, the displacement is obtained. The displacement vector is stored on the cell vertex and a vertex based finite volume are formed with the integral surface and the strain tensor and stress tensor are assumed as uniform in the cell. Compared to the other method, the conservation characteristic of finite volume method is very good and can be applied to irregular shape.3. The stress drive and pressure drive two dimensional interacting of fluid-solid wave propagation is simulated.The wave propagation characteristics in two-dimension elastic structures, structures coupled with standing water or water coupled with air was simulated. These calculation results show that such unstructured grid finite volume time domain method is suitable for elastic-acoustic coupled problems.