Improvement in a moving mesh algorithm and development of a central difference algorithm for the solution of unsteady flows

In this research a simple and improved algorithm for simulating of rotational or oscillating motion of body and also solving the governing equations of flow is presented. in order to mesh the solution domain، a hybrid mesh which is combined with quadrilateral and triangle elements is used. In the moving mesh algorithm، rotational or oscillating motion of body is simply practicable so that it does not need any of common methods in moving mesh such as interpolation، insertion or deletion and remeshing. Discretization of solution domain in this research is based on Control Volume based Finite Element Method (CVFEM) and for solving the governing equations Jameson central difference algorithm is developed based on the mentioned discretization method. One of the advantages of this Approach is that it does not require finding information of neighbor elements; this subject is very important in solution of three dimensional problems and it noticeably facilitates the amount of data structure. In addition، in this approach the properties of flow are computed directly on domain vertices، so boundary condition are applied directly on boundary vertices and as a result the flow properties are computed exactly on boundaries. In this research، to accelerate convergence، local pseudo-time stepping، enthalpy damping and residual averaging are used on unsteady and compressible two dimensional forms of Euler equations. At the end، to make sure of the accuracy of the results، these results are compared either with experimental or other numerical available data.