A numerical treatment of specified pressure boundary conditions based on collocated grid

Key words:  specified pressure boundary  collocated grid  pressure equation  IDEAL  algorithm

Abstract:

The idea of SIMPLE-P algorithm dealing with pressure boundary was extended to collocated grid system. The pressure equation of boundary control volume was reconstructed in consideration of the mathematical characters of the pressure and velocity boundary conditions. The solving steps of flow and heat transfer problem in specified pressure boundary conditions were discussed based on the IDEAL algorithm dealing with pressure and velocity coupling. The methods were evaluated by Kovasznay flow，pressure-driven laminar internal flow and buoyancy-driven flow, and the solutions were compared with those obtained from the literature and experiment. The results show that the proposed method is accurate and efficient. For the specified pressure boundary problem, it has better convergence performance than SIMPLE-P algorithm. Especially for the problem of natural convection in large-space, the good accuracy solutions can be obtained by the new method with a relatively small domain, which can save large number of storage space and computing time.