Composite grid and finite-volume LU implicit scheme for turbine flow analysisA composite grid was generated in an attempt to improve grid quality for a typical turbine blade with large camber in terms of mesh control, smoothness, and orthogonality. This composite grid consists of the C grid (or O grid) in the immediate vicinity of the blade and the H grid in the upstream region and in the middle of the blade passage between the C grids. It provides a good boundary layer resolution around the leading edge region for viscous calculation, has orthogonality at the blade surface and slope continuity at the C-H (or O-H) interface, and has flexibility in controlling the mesh distribution in the upstream region without using excessive grid points. This composite grid eliminates the undesirable qualities of a single grid when generated for a typical turbine geometry. A finite-volume lower-upper (LU) implicit schemes can be used in solving for the turbine flows on the composite grid. This grid has a special grid node that is connected to more than four neighboring nodes in two dimensions and to more than six nodes in three dimensions. But the finite-volume approach poses no problem at the special point because each interior cell has only four neighboring cells in two dimensions and only six cells in three dimensions. The finite-volume LU implicit scheme was demonstrated to be robust and efficient for both external and internal flows in a broad flow regime.
Document ID
19870054804
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Choo, Yung K. (NASA Lewis Research Center Cleveland, OH, United States)
Yoon, Seokkwan (NASA Lewis Research Center; Sverdrup Technology, Inc. Cleveland, OH, United States)
Civinskas, Kestutis C. (NASA Lewis Research Center; U.S. Army, Propulsion Directorate, Cleveland OH, United States)