Basics : Backward facing step
Fluid velocity fringes
*KEYWORD *TITLE *DATABASE_BINARY_D3PLOT *DEFINE_CURVE_TITLE *ICFD_BOUNDARY_NONSLIP *ICFD_BOUNDARY_PRESCRIBED_VEL *ICFD_BOUNDARY_PRESCRIBED_PRE *ICFD_CONTROL_GENERAL *ICFD_CONTROL_OUTPUT *ICFD_CONTROL_STEADY *ICFD_MAT *ICFD_PART *ICFD_PART_VOL *ICFD_SECTION *INCLUDE *MESH_SURFACE_ELEMENT *MESH_SURFACE_NODE *MESH_VOLUME *PARAMETER *END
$----------------------------------------------------------------------------- $ $ Example provided by Iñaki (LSTC) $ $ E-Mail: info@dynamore.de $ Web: http://www.dynamore.de $ $ Copyright, 2015 DYNAmore GmbH $ Copying for non-commercial usage allowed if $ copy bears this notice completely. $ $X------------------------------------------------------------------------------ $X $X 1. Run file as is. $X Requires LS-DYNA MPP Dev 114223 (or higher) with double precision $X $X------------------------------------------------------------------------------ $# UNITS: Dimensionless $X------------------------------------------------------------------------------ $X *KEYWORD *TITLE ICFD Laminar Backward facing step *INCLUDE mesh.k $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ PARAMETERS $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *PARAMETER I It_max 10000 R dt_plot 200 $ $--- Fluid $ Rrho_fluid 1 R mu_fluid 1.6665e-3 Rvel_fluid 1 $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ ICFD CONTROL CARDS $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *ICFD_CONTROL_GENERAL 1 0 0 *ICFD_CONTROL_STEADY &It_max 1e-8 1e-8 1 1 1 0 *ICFD_CONTROL_OUTPUT $# msgl 3 $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ ICFD PARTS/ SECTION/ MATERIAL $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *ICFD_MAT $# mid flg ro vis 1 1&rho_fluid &mu_fluid *ICFD_PART $# pid secid mid 1 1 1 *ICFD_PART $# pid secid mid 2 1 1 *ICFD_PART $# pid secid mid 3 1 1 *ICFD_PART_VOL $# pid secid mid 10 1 1 $# spid1 spid2 spid3 1 2 3 *ICFD_SECTION $# sid 1 $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ ICFD BOUNDARY/INITIAL/LOAD CONDITIONS $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *ICFD_BOUNDARY_NONSLIP $# pid 3 *ICFD_BOUNDARY_PRESCRIBED_VEL $# pid dof vad lcid sf vid death birth 1 1 1 1 1.000000 01.0000E+28 0.000 *ICFD_BOUNDARY_PRESCRIBED_VEL $# pid dof vad lcid sf vid death birth 1 2 1 2 1.000000 01.0000E+28 0.000 *ICFD_BOUNDARY_PRESCRIBED_PRE $# pid dof vad lcid sf vid death birth 2 1 1 2 1.000000 01.0000E+28 0.000 *DEFINE_CURVE_TITLE Vel Inlet $# lcid sidr sfa sfo offa offo dattyp 1 &vel_fluid $# a1 o1 0.0 1.0 10000.0 1.0 *DEFINE_CURVE $# lcid sidr sfa sfo offa offo dattyp 2 $# a1 o1 0.0 0.0 10000.0 0.0 *ICFD_INITIAL $# pid 0 1 $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ ICFD MESH KEYWORDS $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *MESH_VOLUME $# volid 10 $# pid1 pid2 pid3 1 2 3 *MESH_BL $# pid 3 1 *MESH_BL_SYM $# pid 1 *MESH_BL_SYM $# pid 2 $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ DATABASE (OUTPUT) $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *DATABASE_BINARY_D3PLOT &dt_plot *END
The 2D laminar backward facing step is a widely encountered benchmark for CFD code testing. The present example features a mesh size of 0.05 and a Reynolds number of 800. The second order steady state solver is used.
References :
[1] B. F. ARMALY, F. DURSTS, J. C. F. PEREIRA AND B. SCHONUNG , Experimental and theoretical investigation of backward-facing step flow, Institute of Hydromechanics, Section I11 : Mechanics of Turbulent Flows, University of Karlsruhe, KaiserstraBe 12, D-7500 Karlsruhe, F.R.G.
[2] EXPERIMENTAL AND NUMERICAL INVESTIGATION OF 2-D BACKWARD-FACING STEP FLOW. T. LEE AND D. MATEESCU Department of Mechanical Engineering, McGill University, Montreal, Quebec, Canada
[3] E. Erturk,Numerical solutions of 2-D steady incompressible flow over a backward-facing step, Part I: High Reynolds number solutions,Gebze Institute of Technology, Energy Systems Engineering Department, Gebze, Kocaeli 41400, Turkey