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Wind tunnel flow simulation boundary condition issue |
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October 21, 2021, 09:27 |
Wind tunnel flow simulation boundary condition issue
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charan
Join Date: Aug 2021
Posts: 11
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Hi everybody
I am actually try to simulate WIND TUNNEL flow . the following are the inlet and outlet conditions: Inlet static pressure: 90419 Pa static temp: 296.97 k velocity: 2.374 m/s Outlet static pressure : 90057 Pa static temp: 295.75 k Velocity: 26.23 m/s Density: 1.0609 (constant throughout the tunnel) Viscosity : 1.83*10^-5 N.s/m^2 (constant throughout the tunnel) I have been facing following issues 1. as the flow regime is in incompressible, i started with INC_RANS, where i used (velocity inlet & pressure outlet), (pressure inlet & pressure outlet) both has diverged. 2. i moved onto compressible solver where i took total condition at inlet & static back pressure at outlet. After solving the pressure is measure at the outlet where it is 89999 Pa instead of 90057 Pa. velocity at inlet : 3.85 m/s ( actual:2.374 m/s). velocity at outlet: 45.11 m/s (actual: 26.23 m/s ). 3. Pressure, velocity, temperature of inlet & outlet are different from the one which where imposed on them. 4. a change in initializing values ( freestream values) are also influencing the boundary condition parameters. 5. The solution is not stabilizing. It would very helpful, if you can solve any of my issues. i am attaching my cfg file along with this for reference. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % SU2 configuration file % % Case description: ALFA WTM % % Author: CHARAN PATTABHI % % Date: 10.12.2021 % % File Version 7.1.1 "Blackbird" % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------% % % Physical governing equations (EULER, NAVIER_STOKES, % WAVE_EQUATION, HEAT_EQUATION, FEM_ELASTICITY, % POISSON_EQUATION) SOLVER= RANS % % Specify turbulence model (NONE, SA, SA_NEG, SST, SA_E, SA_COMP, SA_E_COMP, SST_SUST) KIND_TURB_MODEL= SST % % Transition model (NONE, BC) % KIND_TRANS_MODEL= NONE % % Mathematical problem (DIRECT, CONTINUOUS_ADJOINT) MATH_PROBLEM= DIRECT % % Restart solution (NO, YES) RESTART_SOL= NO % SYSTEM_MEASUREMENTS= SI % %-------------------- COMPRESSIBLE FREE-STREAM DEFINITION --------------------% % % Mach number (non-dimensional, based on the free-stream values) MACH_NUMBER= 0.098 % % Angle of attack (degrees, only for compressible flows) AOA= 0 % % Side-slip angle (degrees, only for compressible flows) SIDESLIP_ANGLE= 0.0 % % Init option to choose between Reynolds (default) or thermodynamics quantities % for initializing the solution (REYNOLDS, TD_CONDITIONS) % INIT_OPTION= TD_CONDITIONS % Free-stream option to choose between density and temperature (default) for % initializing the solution (TEMPERATURE_FS, DENSITY_FS) % FREESTREAM_OPTION= TEMPERATURE_FS % % Free-stream pressure (101325.0 N/m^2, 2116.216 psf by default) FREESTREAM_PRESSURE= 89808 % Free-stream temperature (288.15 K by default) FREESTREAM_TEMPERATURE= 294.93 % % Reynolds number (non-dimensional, based on the free-stream values) REYNOLDS_NUMBER= 209741.73 % % Reynolds length (1 m by default) REYNOLDS_LENGTH= 0.1064 %^ % Free-stream turbulence intensity FREESTREAM_TURBULENCEINTENSITY= 0.015 % % Free-stream ratio between turbulent and laminar viscosity FREESTREAM_TURB2LAMVISCRATIO= 10.0 % % --------------------------- VISCOSITY MODEL ---------------------------------% % % Viscosity model (SUTHERLAND, CONSTANT_VISCOSITY). VISCOSITY_MODEL= CONSTANT_VISCOSITY % % Molecular Viscosity that would be constant (1.716E-5 by default) MU_CONSTANT= 1.830e-05 % ---- NONEQUILIBRIUM GAS, IDEAL GAS, POLYTROPIC, VAN DER WAALS AND PENG ROBINSON CONSTANTS -------% % % Fluid model (STANDARD_AIR, IDEAL_GAS, VW_GAS, PR_GAS, % CONSTANT_DENSITY, INC_IDEAL_GAS, INC_IDEAL_GAS_POLY, MUTATIONPP, SU2_NONEQ) FLUID_MODEL= STANDARD_AIR % % Ratio of specific heats (1.4 default and the value is hardcoded % for the model STANDARD_AIR, compressible only) GAMMA_VALUE= 1.4 % % Specific gas constant (287.058 J/kg*K default and this value is hardcoded % for the model STANDARD_AIR, compressible only) GAS_CONSTANT= 287.058 % % % % ---------------------- REFERENCE VALUE DEFINITION ---------------------------% % % Reference origin for moment computation REF_ORIGIN_MOMENT_X = 0.8425 REF_ORIGIN_MOMENT_Y = 0.00 REF_ORIGIN_MOMENT_Z = 0.012 % % Reference length for pitching, rolling, and yawing non-dimensional moment REF_LENGTH= 0.1064 % % Reference area for force coefficients (0 implies automatic calculation) REF_AREA= 0.226 % -------------------- BOUNDARY CONDITION DEFINITION --------------------------% % % Navier-Stokes wall boundary marker(s) (NONE = no marker) MARKER_HEATFLUX= ( AAA,0.0,AFTBODY,0.0,BULKHEAD,0.0,COWL_1,0.0,COWL_2 ,0.0,FUSE,0.0,HT,0.0,HT-HINGE,0.0,NOSE,0.0,STING,0.0,VT,0.0,VT-HINGE,0.0,WING,0.0,WING-HINGE,0.0 ) % % Inlet boundary type (TOTAL_CONDITIONS, MASS_FLOW) INLET_TYPE= TOTAL_CONDITIONS % % Inlet boundary marker(s) (NONE = no marker) % % Inlet boundary marker(s) with the following formats (NONE = no marker) % Total Conditions: (inlet marker, total temp, total pressure, flow_direction_x, % flow_direction_y, flow_direction_z, ... ) where flow_direction is % a unit vector. % Mass Flow: (inlet marker, density, velocity magnitude, flow_direction_x, % flow_direction_y, flow_direction_z, ... ) where flow_direction is % a unit vector. % Inc. Velocity: (inlet marker, temperature, velocity magnitude, flow_direction_x, % flow_direction_y, flow_direction_z, ... ) where flow_direction is % a unit vector. % Inc. Pressure: (inlet marker, temperature, total pressure, flow_direction_x, % flow_direction_y, flow_direction_z, ... ) where flow_direction is % a unit vector. MARKER_INLET= ( A-IINLET, 296.97, 90422.12, 1.0, 0.0, 0.0 ) % % Outlet boundary marker(s) (NONE = no marker) % Compressible: ( outlet marker, back pressure (static thermodynamic), ... ) % Inc. Pressure: ( outlet marker, back pressure (static gauge in Pa), ... ) % Inc. Mass Flow: ( outlet marker, mass flow target (kg/s), ... ) MARKER_OUTLET= ( AA-OUTLET, 90057.00 ) % % Symmetry boundary marker(s) (NONE = no marker) % MARKER_SYM= ( symmetry ) % % Marker(s) of the surface to be plotted or designed MARKER_PLOTTING= ( AFTBODY,BULKHEAD,COWL_1,COWL_2,FUSE,HT,HT-HINGE,NOSE,STING,VT,VT-HINGE,WING,WING-HINGE ) % % Marker(s) of the surface where the functional (Cd, Cl, etc.) will be evaluated MARKER_MONITORING= ( AFTBODY,BULKHEAD,COWL_1,COWL_2,FUSE,HT,HT-HINGE,NOSE,STING,VT,VT-HINGE,WING,WING-HINGE ) % Marker(s) of the surface that is going to be analyzed in detail (massflow, average pressure, distortion, etc) MARKER_ANALYZE = ( A-IINLET, AA-OUTLET ) % Method to compute the average value in MARKER_ANALYZE (AREA, MASSFLUX). MARKER_ANALYZE_AVERAGE = MASSFLUX % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------% % % Numerical method for spatial gradients (GREEN_GAUSS, LEAST_SQUARES, % WEIGHTED_LEAST_SQUARES) NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES % % Courant-Friedrichs-Lewy condition of the finest grid CFL_NUMBER= 10 % % Adaptive CFL number (NO, YES) CFL_ADAPT= NO % % Parameters of the adaptive CFL number (factor down, factor up, CFL min value, % CFL max value ) CFL_ADAPT_PARAM= ( 0.1, 2.0, 100.0, 1e3 ) % % Runge-Kutta alpha coefficients RK_ALPHA_COEFF= ( 0.66667, 0.66667, 1.000000 ) % % Number of total iterations ITER= 600 % ------------------------ LINEAR SOLVER DEFINITION ---------------------------% % % Linear solver for implicit formulations (BCGSTAB, FGMRES) LINEAR_SOLVER= FGMRES % % Preconditioner of the Krylov linear solver (JACOBI, LINELET, LU_SGS) LINEAR_SOLVER_PREC= LU_SGS % % Linael solver ILU preconditioner fill-in level (0 by default) LINEAR_SOLVER_ILU_FILL_IN= 0 % % Minimum error of the linear solver for implicit formulations LINEAR_SOLVER_ERROR= 1E-8 % % Max number of iterations of the linear solver for the implicit formulation LINEAR_SOLVER_ITER= 10 % ----------------------- SLOPE LIMITER DEFINITION ----------------------------% % % Coefficient for the limiter VENKAT_LIMITER_COEFF=0.1 % % Coefficient for the sharp edges limiter ADJ_SHARP_LIMITER_COEFF= 3.0 % % Reference coefficient (sensitivity) for detecting sharp edges. REF_SHARP_EDGES= 3.0 % % Remove sharp edges from the sensitivity evaluation (NO, YES) SENS_REMOVE_SHARP= NO % -------------------------- MULTIGRID PARAMETERS -----------------------------% % % Multi-Grid Levels (0 = no multi-grid) MGLEVEL= 0 % % Multi-grid cycle (V_CYCLE, W_CYCLE, FULLMG_CYCLE) MGCYCLE= V_CYCLE % % Multi-grid pre-smoothing level MG_PRE_SMOOTH= ( 1, 1, 1, 1 ) % % Multi-grid post-smoothing level MG_POST_SMOOTH= ( 0, 0, 0, 0 ) % % Jacobi implicit smoothing of the correction MG_CORRECTION_SMOOTH= ( 0, 0, 0, 0 ) % % Damping factor for the residual restriction MG_DAMP_RESTRICTION= 0.8 % % Damping factor for the correction prolongation MG_DAMP_PROLONGATION= 0.8 % -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------% % % Convective numerical method (JST, LAX-FRIEDRICH, CUSP, ROE, AUSM, HLLC, % TURKEL_PREC, MSW) CONV_NUM_METHOD_FLOW= ROE % % Monotonic Upwind Scheme for Conservation Laws (TVD) in the flow equations. % Required for 2nd order upwind schemes (NO, YES) MUSCL_FLOW= YES % % Slope limiter (NONE, VENKATAKRISHNAN, VENKATAKRISHNAN_WANG, % BARTH_JESPERSEN, VAN_ALBADA_EDGE) SLOPE_LIMITER_FLOW= NONE % % Time discretization (RUNGE-KUTTA_EXPLICIT, EULER_IMPLICIT, EULER_EXPLICIT) TIME_DISCRE_FLOW= EULER_IMPLICIT % -------------------- TURBULENT NUMERICAL METHOD DEFINITION ------------------% % % Convective numerical method (SCALAR_UPWIND) CONV_NUM_METHOD_TURB= SCALAR_UPWIND % % Monotonic Upwind Scheme for Conservation Laws (TVD) in the turbulence equations. % Required for 2nd order upwind schemes (NO, YES) MUSCL_TURB= NO % % Slope limiter (VENKATAKRISHNAN, MINMOD) SLOPE_LIMITER_TURB= VENKATAKRISHNAN % % Time discretization (EULER_IMPLICIT) TIME_DISCRE_TURB= EULER_IMPLICIT % --------------------------- CONVERGENCE PARAMETERS --------------------------% % % Convergence criteria (CAUCHY, RESIDUAL) CONV_FIELD= RMS_DENSITY % % Min value of the residual (log10 of the residual) CONV_RESIDUAL_MINVAL= -6 % % Start convergence criteria at iteration number CONV_STARTITER= 10 % % Number of elements to apply the criteria CONV_CAUCHY_ELEMS= 100 % % Epsilon to control the series convergence CONV_CAUCHY_EPS= 1E-6 % % ------------------------- SCREEN/HISTORY VOLUME OUTPUT --------------------------% % % Screen output SCREEN_OUTPUT= (INNER_ITER, WALL_TIME, RMS_DENSITY, RMS_PRESSURE, LIFT, DRAG) % % History output groups (use 'SU2_CFD -d <config_file>' to view list of available fields) HISTORY_OUTPUT= (ITER, WALL_TIME,AERO_COEFF, FLOW_COEFF, RMS_RES ) % % Volume output fields/groups (use 'SU2_CFD -d <config_file>' to view list of available fields) VOLUME_OUTPUT= (COORDINATES, SOLUTION, PRIMITIVE, RESIDUAL) % % Writing frequency for screen output SCREEN_WRT_FREQ_INNER= 1 % SCREEN_WRT_FREQ_OUTER= 1 % SCREEN_WRT_FREQ_TIME= 1 % % Writing frequency for history output HISTORY_WRT_FREQ_INNER= 1 % HISTORY_WRT_FREQ_OUTER= 1 % HISTORY_WRT_FREQ_TIME= 1 % % Writing frequency for volume/surface output OUTPUT_WRT_FREQ= 10 % % ------------------------- INPUT/OUTPUT INFORMATION --------------------------% % % Mesh input file MESH_FILENAME= a_10_su2.cgns % % Mesh input file format (SU2, CGNS, NETCDF_ASCII) MESH_FORMAT= CGNS % % Mesh output file MESH_OUT_FILENAME= mesh_out.su2 % % Restart flow input file SOLUTION_FILENAME= restart_flow.dat % % Restart adjoint input file SOLUTION_ADJ_FILENAME= solution_adj.dat % % Output file format (PARAVIEW, TECPLOT, SLT) TABULAR_FORMAT= CSV % % Files to output % Possible formats : (TECPLOT, TECPLOT_BINARY, SURFACE_TECPLOT, % SURFACE_TECPLOT_BINARY, CSV, SURFACE_CSV, PARAVIEW, PARAVIEW_BINARY, SURFACE_PARAVIEW, % SURFACE_PARAVIEW_BINARY, MESH, RESTART_BINARY, RESTART_ASCII, CGNS, STL) % default : (RESTART, PARAVIEW, SURFACE_PARAVIEW) OUTPUT_FILES= (RESTART, PARAVIEW, SURFACE_PARAVIEW) % % Output file convergence history (w/o extension) CONV_FILENAME= history % WRT_FORCES_BREAKDOWN=YES BREAKDOWN_FILENAME= forces_breakdown.dat % % Output file restart flow RESTART_FILENAME= restart_flow.dat % % % Output file flow (w/o extension) variables VOLUME_FILENAME= flow % % % % Output file surface flow coefficient (w/o extension) SURFACE_FILENAME= surface_flow % % % |
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