Numerical Method Research Based On Dynamic Unstructured Grids And Kinetic Object Surface Viscous Flow Field

The article studied the unstructured dynamic mesh technology and combinesunstructured dynamic meshes technology with the finite volume method to solveNervier-Stokes equations. And establishes calculation model based on the unsteadynumerical discrete of the unstructured dynamic meshes.This paper developed two kinds of dynamic mesh generation technologies. Oneis the improved spring analogy; the method is improved on basis of the standardspring analogy method. Improved method besides considering affective of preventingthe collision between grid nodes in standard spring method and considering reverse、space and boundary effects. Those effects make the deformation of grids enhancegreater than standard spring analogy method. The second dynamic mesh method ispartial reconstruction. The method can effectively solve objects’ large motion which isthat the spring analogy can not solve. This paper proposes an improved method,which will improve the stationing ability of Delaunay triangle methods, avoid thetedious steps in extracting window boundary, and boost computational speed andassure the quality of the grid. At last we compile two Programs. The first isunstructured dynamic mesh program bases on improved spring analogy. The second isunstructured dynamic mesh program bases on partial reconstruction.This paper establishes numerical model which combined dynamic meshtechnology with SIMPLE algorithm and gives discrete method of numericalsimulation and boundary conditions and GCL’s discrete form which are appropriatefor dynamic mesh technology. The accuracy of grid information transmissiondetermines accuracy of simulation in dynamic mesh numerical simulation. This papercombines bilinear interpolation with ENO interpolation to calculate the interpolatedparameters. This interpolation method has second order accuracy. The paper compilesnumerical calculation program which bases on the unstructured dynamic meshtechnology with help of FORTRAN language. And than uses the program study thePeriodic oscillation of the horizontal cylinder. We find that the program is reliableafter compare calculation results with FLUENT software’s and can be used to solvethe Numerical Analysis of the moving body.Objects’ flexible deformation is expected to suppress adverse effects ofvortex-induced vibration in the marine engineering. By preliminary study of ours twocases, we find that objects’ flexible deformation can change the structure of originalflow, and make the vortex shedding location shift to the rear. Flexible plates’ application, which is edge of cylinder, can make the vortex shedding is no longerrules, and effectively inhibits objects’ vortex-induced vibration.