{"title":"An Optimized Multi-block Method for Turbulent Flows","authors":"M. Goodarzi, P. Lashgari","volume":24,"journal":"International Journal of Mechanical and Mechatronics Engineering","pagesStart":1291,"pagesEnd":1295,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/12149","abstract":"A major part of the flow field involves no complicated\r\nturbulent behavior in many turbulent flows. In this research work, in\r\norder to reduce required memory and CPU time, the flow field was\r\ndecomposed into several blocks, each block including its special\r\nturbulence. A two dimensional backward facing step was considered\r\nhere. Four combinations of the Prandtl mixing length and standard k-\r\nE models were implemented as well. Computer memory and CPU\r\ntime consumption in addition to numerical convergence and accuracy\r\nof the obtained results were mainly investigated. Observations\r\nshowed that, a suitable combination of turbulence models in different\r\nblocks led to the results with the same accuracy as the high order\r\nturbulence model for all of the blocks, in addition to the reductions in\r\nmemory and CPU time consumption.","references":"[1] Weatherill N.P, and forsey C. R., \"Grid Genaration and Flow\r\ncalculation for Complex Aircraft Geometries Using a Multi-Block\r\nScheme\", AIAA Paper, 85, 1985.\r\n[2] Jae Wook Kim, and Duck Joo Lee., \"Characteristic Interface\r\nConditions for Multiblock High-Order Computation on singular\r\nStructured Grid\", AIAA Journal, Vol. 41, No. 12, pp.2341-2348, 2003.\r\n[3] Epstein B, Rubin T, and Seror S., \"Accurate Multiblock Navier - Stokes\r\nSolver for Complex Aerodynamic Configurations\", AIAA Journal, Vol.\r\n41, No. 4, pp. 582-593, 2003.\r\n[4] Drikakis D., \"A Parallel Multiblock Characteristic-Based Method for\r\nThree-Dimensional Incompressible Flow\", Advances in Engineering\r\nSoftware, Vol. 26, pp.111-119, 1996.\r\n[5] Di Serafino Daniela., \"A Parallel Implementation of a Multigrid\r\nmultiblock Euler Solver on Distributed Memory Machines\", parallel\r\nComputing, Vol. 23, pp. 2095-2113, 1997.\r\n[6] Tsai H.M, Wong A.S.F, Cai J, and Liu F., \"Unsteady Flow calculations\r\nwith a parallel Multiblock Moving Mesh Algorithm\", AIAA Journal,\r\nVol. 39, No. 6, pp.1021-1029, 2001.\r\n[7] Atkins H.L., \"A Multi-block Multigrid Method for the Solution of the\r\nEuler and Navier - stokes Equations for Three Dimensional Flows\",\r\nAIAA Paper, 91, 101, 1991.\r\n[8] Prandtl L., \"\u251c\u00a3ber Die Ausgebildete Turbulenz\", ZAMM, Vol. 5, pp. 136-\r\n139, 1925.\r\n[9] Launder B.E, and Spalding D.B., \"The Numerical Computation of\r\nTurbulent Flow\", Comput. Methods Appl. Mech. Eng, Vol. 3, pp. 269-\r\n289, 1974.\r\n[10] Rhie CM, Chow WL. \"Numerical Study of the Turbulent Flow Past an\r\nAirfoil with Trailing Edge Separation\". AIAA J. 1983; 21: 1525-1532.\r\n[11] Kim J, Kline S.J and Johnston J.P., \"Investigation of a Reattaching\r\nTurbulent Shear Layer: Flow over a Backward-Facing Step\", J. Fluid\r\nEng., ASME Trans, Vol. 102, pp. 302-308, 1980.\r\n[12] Hackman P.L, Raithby G.D and Strong A.B., \"Numerical Predication of\r\nFlows Over Backward Facing Step by a Finite Element Method;\r\nComparison with Finite Volume Solutions and Experiments\", Int. J.\r\nNumer. Methods Fluids, Vol. 4, pp. 711-724, 1984.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 24, 2008"}