Parameter investigation for computing time reduction with Lower-Upper Symmetric Gauss-Seidel and line-implicit methods
2014 (English)In: AIAA AVIATION 2014 -7th AIAA Theoretical Fluid Mechanics Conference, 2014Conference paper (Refereed)
An implicit Lower-Upper Symmetric Gauss-Seidel (LU-SGS) solver has been implemented as a multigrid (MG) smoother combined with a line-implicit method as an acceleration technique for Reynolds-Averaged Navier-Stokes (RANS) simulation on stretched meshes. The Computational Fluid Dynamics (CFD) code concerned is Edge, an edge- based finite volume Navier-Stokes flow solver for structured and unstructured grids. The paper focuses on the investigation of the parameters related to the novel line-implicit LU- SGS solver for convergence acceleration on 3D RANS meshes. The influence on the overall convergence of the Courant-Friedrichs-Lewy (CFL) number, the Left Hand Side (LHS) dissipation, and the convergence of iterative solution of the linear problem is presented and default values are defined for maximum convergence acceleration. These optimized set- tings are applied to 3D RANS computations for comparison with explicit and line-implicit Runge-Kutta (RK) smoothing. For most of the cases, a computing time acceleration of the order of 2 is found depending on the mesh type, namely the boundary layer and the magnitude of residual reduction.
Place, publisher, year, edition, pages
Aviation, Computational fluid dynamics, Fluid mechanics
IdentifiersURN: urn:nbn:se:kth:diva-168556ScopusID: 2-s2.0-84906996725OAI: oai:DiVA.org:kth-168556DiVA: diva2:817151
AIAA AVIATION 2014 -7th AIAA Theoretical Fluid Mechanics Conference 2014; Atlanta, GA; United States
QC 201506042015-06-042015-06-042015-06-04Bibliographically approved