In this study the turbulent flow in a circular diffuser with various diffusion angles is investigated using numerical method. To fit the irregular boundaries of the diffuser curvi-linear nonorthogonal coordinates are employed. The finite-volume method is used to discretize the governing equations. The grids are arranged in the nonuniform and non-staggered manner. Three difference schemes, including upwind difference (UD), linear upwind difference (LUD) and the SOUCUP of Zhu and Rodi, are adopted to approximate the convection terms. Results indicate that the LUD and the SOUCUP can effectively reduce numerical diffusion, which is the main disadvantage of the UD, and yield better agreement with measurements. The LUD may produce oscillations in solution, especially with coarse grids. But the unbounded solution oscillation can be avoided by refining the grid. As for SOUCUP, the solution unboundness can be effectively suppressed. However, the residual of SOUCUP may not be relaxed, which may prevent the solution iteration from convergence.
|Number of pages||8|
|Journal||Journal of the Chinese Society of Mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Ch'eng Hsuebo Pao|
|State||Published - 1 Aug 1996|