Adaptive mesh refinement and recovery for finite element wind analysis

For the efficient finite element wind analysis, using the optimal mesh is one of the most important factors. The optimal mesh can be obtained when the errors of the solution are distributed uniformly over the entire domain. This paper presents the development of a transition element for flow analysis which has a variable number of mid-side nodes and can be effectively used in the adaptive mesh refinement by connecting the locally refined mesh to the existing coarse mesh through a minimum mesh modification. In the dynamic analysis of flow, the optimal mesh should be changed continuously in accordance with the changing error distribution and the proposed refinement/recovery scheme was found to be very effective for this purpose. The modified superconvergent patch recovery for the variable-node element is presented to estimate a posteriori error of the solution for the adaptive mesh refinement. The boundary conditions of the generated nodes by refinement process are different from those used ordinary finite element method in order to describe the singular point correctly. The numerical examples show that the optimal mesh for the finite element analysis of flow around the structures can be obtained automatically by the proposed scheme.