Implementation of the IDEAL Algorithm on Nonorthogonal Curvilinear Coordinates for the Solution of 3-D Incompressible Fluid Flow and Heat Transfer Problems

Recently an efficient segregated algorithm for incompressible fluid flow and heat transfer problems, called IDEAL (Inner Doubly Iterative Efficient Algorithm for Linked Equations), has been proposed by the present authors. In the algorithm there exist inner doubly iterative processes for the pressure equation at each iteration level, which almost completely overcome the two approximations in the SIMPLE algorithm. Thus the coupling between velocity and pressure is fully guaranteed, greatly enhancing the convergence rate and stability of the solution process. In this article, the IDEAL algorithm is extended to the body-fitted collocated grid systems in 3-D nonorthogonal curvilinear coordinates. The extended IDEAL algorithm adopts two successful methods. One is that the interfacial contravariant velocity is calculated by the modified momentum interpolation method (MMIM); the other is that the interfacial contravariant velocity is improved by solving the pressure equation directly. Finally, three 3-D incompressible fluid flow and heat transfer problems are provided to compare the convergence rate and robustness between IDEAL and three other algorithms (SIMPLEM, SIMPLERM, and SIMPLECM). From the comparison it can be concluded that the IDEAL algorithm is more robust and efficient than the three other algorithms.