Parallel Implementation of Periodic Boundary Conditions for a Curvilinear Immersed Boundary Method

In this paper, a periodic boundary condition is implemented for 3D unsteady finite volume solver for incompressible Navier-Stokes equations on curvilinear structured grids containing moving immersed boundaries of arbitrary geometrical complexity. The governing equations are discretized with second-order accuracy on a hybrid staggered/non-staggered grid layout. The discrete equations are integrated in time via a second-order fractional step method. To resolve all the relevant scales in the flow accurately, a high-resolution curvilinear mesh is required, i.e., the simulations are computationally expensive. Therefore, high-performance parallel computing is essential to obtain results within reasonable time for practical applications. The main challenge with the implantation of the parallel periodic boundary condition is to update information at ghost nodes on different processors. An efficient parallel algorithm is implemented to update the ghost nodes for the periodic boundary condition. The parallel implementation is tested by comparing the results with analytical solutions, which are found to be in excellent agreement with each other. The parallel performance of the solver with the periodic boundary condition is also investigated for different cases.