Transonic flow around NACA0012
The NACA airfoils are airfoil shapes for aircraft wings developed by the National Advisory Committee for Aeronautics (NACA, former NASA) in the 1940s. The four digit series define the profile by describing its maximum camber, the location of the maximum camber and the airfoil’s maximum thickness. The NACA 0012 is a symmetrical airfoil frequently used for benchmarking test cases.
In this test case, the Mach number is high enough to reach the so called transonic flow. Transonic flow occurs when there is mixed subsonic and supersonic local flow in the same flow field (typically with free stream Mach numbers from M = 0.7 or 0.8 to 1.3). When flowing over the airfoil’s surface, the flow will accelerate and become locally supersonic resulting in potential normal shock waves on the upper camber and lower camber. As in this particular test case, the flow will be considered inviscid, no boundary layer will be developed on the airfoil’s surface.
References :
D. L. Bonhaus, A HIGHER ORDER ACCURATE FINITE ELEMENT METHOD FOR VISCOUS COMPRESSIBLE FLOWS, PhD thesis, Virginia Polytechnic Institute and State University, 1998.
CESE pressure isocontours
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$----------------------------------------------------------------------------- $ $ 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 R8.0.0 (or higher) with double precision $X $X------------------------------------------------------------------------------ $# UNITS: Dimensionless $X------------------------------------------------------------------------------ $X *KEYWORD *TITLE CESE Transonic flow around NACA0012 profile *INCLUDE mesh.k $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ PARAMETERS $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *PARAMETER R T_end 20 R dt_plot 0.5 $ $--- Fluid $ R dt_fluid 0.0001 Rcfl_fluid 0.7 R M_1 0.80 R P_1 1.1160714 R ro_1 1.0 R cv 2.790179 R cp 3.90625 *PARAMETER_EXPRESSION Rg,Cp/Cv *PARAMETER_EXPRESSION Ra_1,sqrt(g*(P_1/ro_1)) *PARAMETER_EXPRESSION Ru_1,a_1*M_1 $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ CESE CONTROL CARDS $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *CONTROL_TERMINATION $ endtim endcyc dtmin endeng endmas &T_end *CESE_CONTROL_SOLVER $ iframe iflow igeom 0 1 2 *CESE_CONTROL_TIMESTEP $ iddt cfl dtint 2&cfl_fluid &dt_fluid *CESE_CONTROL_LIMITER $ idlmt alfa beta epsr 1 1.0 1.0 0.2 $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ CESE PARTS/ EOS/ MATERIAL $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *CESE_PART $ pid mid eosid 1 3 *CESE_EOS_IDEAL_GAS $ eosid cv cp 3 &Cv &Cp $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ CESE BOUNDARY/INITIAL CONDITIONS $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *CESE_BOUNDARY_PRESCRIBED_SET $ ssid 1 $ lcid_u lcid_v lcid_w lcid_d lcid_p lcid_t -1 $ sf_u sf_v sf_w sf_d sf_p sf_t &U_1 0.0 0.0 &ro_1 &P_1 *CESE_BOUNDARY_PRESCRIBED_SET $ ssid 3 $ lcid_u lcid_v lcid_w lcid_d lcid_p lcid_t -1 $ sf_u sf_v sf_w sf_d sf_p sf_t &U_1 0.0 0.0 &ro_1 &P_1 *CESE_BOUNDARY_PRESCRIBED_SET $ ssid 4 $ lcid_u lcid_v lcid_w lcid_d lcid_p lcid_t -1 $ sf_u sf_v sf_w sf_d sf_p sf_t &U_1 0.0 0.0 &ro_1 &P_1 *CESE_BOUNDARY_NON_REFLECTIVE_SET $ ssid 2 *CESE_BOUNDARY_SOLID_WALL_SET $ ssid 5 *CESE_INITIAL $ uic vic wic rhoic pic tic &U_1 0.0 0.0 &ro_1 &P_1 $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 $ $ $ DATABASE (OUTPUT) $ $ $ $---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 *DATABASE_BINARY_D3PLOT &dt_plot *END