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Divergence of DDES based on steady RANS

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Old   October 23, 2023, 05:03
Default Divergence of DDES based on steady RANS
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Zhang
Join Date: Mar 2023
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Amber0922 is on a distinguished road
Dear all,

I ran a inlet simulation at 50 times back pressure, and the DDES is based on the RANS steady results. I think it will be relatively stable, but the DDES diverged quickly, while the URANS goes well. I attached my setting below, hoping someone could tell me how I could improve my case.

% ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------%
%
% Physical governing equations (EULER, NAVIER_STOKES,
% WAVE_EQUATION, HEAT_EQUATION, FEM_ELASTICITY,
% POISSON_EQUATION)
SOLVER= RANS
KIND_TURB_MODEL= SST
HYBRID_RANSLES= SA_DDES
%
% Mathematical problem (DIRECT, CONTINUOUS_ADJOINT)
MATH_PROBLEM= DIRECT
%
% Axisymmetric simulation, only compressible flows (NO, YES)
AXISYMMETRIC= NO
%
% Restart solution (NO, YES)
RESTART_SOL= YES
%
% System of measurements (SI, US)
% International system of units (SI): ( meters, kilograms, Kelvins,
% Newtons = kg m/s^2, Pascals = N/m^2,
% Density = kg/m^3, Speed = m/s,
% Equiv. Area = m^2 )
% United States customary units (US): ( inches, slug, Rankines, lbf = slug ft/s^2,
% psf = lbf/ft^2, Density = slug/ft^3,
% Speed = ft/s, Equiv. Area = ft^2 )
SYSTEM_MEASUREMENTS= SI
%
% ------------------------- UNSTEADY SIMULATION -------------------------------%

TIME_DOMAIN= YES
TIME_MARCHING= DUAL_TIME_STEPPING-2ND_ORDER
TIME_STEP= 5E-7
MAX_TIME= 1
UNST_CFL_NUMBER= 0.0
INNER_ITER= 30
TIME_ITER = 8000
RESTART_ITER=2
% Time iteration to start the windowed time average in a direct run
WINDOW_START_ITER = 7000
% Window used for reverse sweep and direct run. Options (SQUARE, HANN, HANN_SQUARE, BUMP) Square is default.
WINDOW_FUNCTION = SQUARE
%
% -------------------- COMPRESSIBLE FREE-STREAM DEFINITION --------------------%
%
% Mach number (non-dimensional, based on the free-stream values) the only parameter of the computation!!!
MACH_NUMBER= 6
%
% 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= REYNOLDS
%
% 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= 2549
%
% Free-stream temperature (288.15 K, 518.67 R by default)
FREESTREAM_TEMPERATURE= 221.55
%
% Reynolds number (non-dimensional, based on the free-stream values)
REYNOLDS_NUMBER= 5.11E+6
%
% Reynolds length (1 m, 1 inch by default)
REYNOLDS_LENGTH= 1.0
%
% Free-stream density (1.2886 Kg/m^3, 0.0025 slug/ft^3 by default)
% FREESTREAM_DENSITY= 0.312
%
% Free-stream velocity (1.0 m/s, 1.0 ft/s by default)
% FREESTREAM_VELOCITY= ( 811.37, 0.00, 0.00 )
%
% Free-stream viscosity (1.853E-5 N s/m^2, 3.87E-7 lbf s/ft^2 by default)
% FREESTREAM_VISCOSITY= 1.42E-5
%
%
% ----------------------------------- END -------------------------------------%


% ---------------------- REFERENCE VALUE DEFINITION ---------------------------%
%
% Reference origin for moment computation (m or in)
REF_ORIGIN_MOMENT_X = 0.25
REF_ORIGIN_MOMENT_Y = 0.00
REF_ORIGIN_MOMENT_Z = 0.00
%
% Reference length for moment non-dimensional coefficients (m or in)
REF_LENGTH= 1.0
%
% Reference area for non-dimensional force coefficients (0 implies automatic
% calculation) (m^2 or in^2)
REF_AREA= 1.0
%
% Aircraft semi-span (0 implies automatic calculation) (m or in)
SEMI_SPAN= 0.0
%
% ----------------------------------- END -------------------------------------%

% ---- 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)
FLUID_MODEL= IDEAL_GAS
%
% 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
%
% Critical Temperature (131.00 K by default)
CRITICAL_TEMPERATURE= 131.00
%
% Critical Pressure (3588550.0 N/m^2 by default)
CRITICAL_PRESSURE= 3588550.0
%
% Acentri factor (0.035 (air))
ACENTRIC_FACTOR= 0.035
%
% Specific heat at constant pressure, Cp (1004.703 J/kg*K (air)).
% Incompressible fluids with energy eqn. only (CONSTANT_DENSITY, INC_IDEAL_GAS).
SPECIFIC_HEAT_CP= 1004.703
%
% Molecular weight for an incompressible ideal gas (28.96 g/mol (air) default)
% Incompressible fluids with energy eqn. only (CONSTANT_DENSITY, INC_IDEAL_GAS).
MOLECULAR_WEIGHT= 28.96
%
% Thermal expansion coefficient (0.00347 K^-1 (air))
% Used with Boussinesq approx. (incompressible, BOUSSINESQ density model only)
THERMAL_EXPANSION_COEFF= 0.00347
%
% ----------------------------------- END -------------------------------------%

% --------------------------- VISCOSITY MODEL ---------------------------------%
%
% Viscosity model (SUTHERLAND, CONSTANT_VISCOSITY).
VISCOSITY_MODEL= SUTHERLAND
%
% Molecular Viscosity that would be constant (1.716E-5 by default)
MU_CONSTANT= 1.716E-5
%
% Sutherland Viscosity Ref (1.716E-5 default value for AIR SI)
MU_REF= 1.716E-5
%
% Sutherland Temperature Ref (273.15 K default value for AIR SI)
MU_T_REF= 273.15
%
% Sutherland constant (110.4 default value for AIR SI)
SUTHERLAND_CONSTANT= 110.4
%
% ----------------------------------- END -------------------------------------%

% --------------------------- THERMAL CONDUCTIVITY MODEL ----------------------%
%
% Conductivity model (CONSTANT_CONDUCTIVITY, CONSTANT_PRANDTL).
CONDUCTIVITY_MODEL= CONSTANT_PRANDTL
%
% Molecular Thermal Conductivity that would be constant (0.0257 by default)
DIFFUSIVITY_CONSTANT= 0.0257
%
% Laminar Prandtl number (0.72 (air), only for CONSTANT_PRANDTL)
PRANDTL_LAM= 0.72
%
% Turbulent Prandtl number (0.9 (air), only for CONSTANT_PRANDTL)
PRANDTL_TURB= 0.90
%
% ----------------------------------- END -------------------------------------%

% ----------------------- BODY FORCE DEFINITION -------------------------------%
%
% Apply a body force as a source term (NO, YES)
BODY_FORCE= NO
%
% Vector of body force values (BodyForce_X, BodyForce_Y, BodyForce_Z)
BODY_FORCE_VECTOR= ( 0.0, 0.0, 0.0 )
%
% ----------------------------------- END -------------------------------------%




% -------------------- BOUNDARY CONDITION DEFINITION --------------------------%
%
% Euler wall boundary marker(s) (NONE = no marker)
MARKER_EULER= ( NONE )
%
% Navier-Stokes (no-slip), constant heat flux wall marker(s) (NONE = no marker)
% Format: ( marker name, constant heat flux (J/m^2), ... )
MARKER_HEATFLUX= ( RAMP, 0.0, COWL,0.0, UPWALL,0.0)
%
% Navier-Stokes (no-slip), isothermal wall marker(s) (NONE = no marker)
% Format: ( marker name, constant wall temperature (K), ... )
MARKER_ISOTHERMAL= ( NONE )
%
% Far-field boundary marker(s) (NONE = no marker)
MARKER_FAR= ( FAR )
%
% Symmetry boundary marker(s) (NONE = no marker)
MARKER_SYM= ( SYM1, SYM2 )
%
% Internal boundary marker(s) e.g. no boundary condition (NONE = no marker)
MARKER_INTERNAL= ( NONE )
%
% Near-Field boundary marker(s) (NONE = no marker)
MARKER_NEARFIELD= ( NONE )
%
% Zone interface boundary marker(s) (NONE = no marker)
MARKER_CHT_INTERFACE= ( NONE )
%
% Inlet boundary type (TOTAL_CONDITIONS, MASS_FLOW)
INLET_TYPE= TOTAL_CONDITIONS
%
% Read inlet profile from a file (YES, NO) default: NO
SPECIFIED_INLET_PROFILE= NO
%
% File specifying inlet profile
% INLET_FILENAME= inlet.dat
%
% 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.
% Incompressible: (inlet marker, temperature, velocity magnitude, flow_direction_x,
% flow_direction_y, flow_direction_z, ... ) where flow_direction is
% a unit vector.
MARKER_INLET= ( NONE )
%
% Outlet boundary marker(s) (NONE = no marker)
% Format: ( outlet marker, back pressure (static), ... )
MARKER_OUTLET= ( OUT, 127450, FAROUT, 2549 )
%

% ----------------------------------- END -------------------------------------%

% ------------------------ SURFACES IDENTIFICATION ----------------------------%
%
% Marker(s) of the surface in the surface flow solution file
MARKER_PLOTTING = ( RAMP, OUT )
%
% Marker(s) of the surface where the non-dimensional coefficients are evaluated.
MARKER_MONITORING = ( RAMP )
%
% Viscous wall markers for which wall functions must be applied. (NONE = no marker)
% Format: ( marker name, wall function type, ... )
MARKER_WALL_FUNCTIONS= ( NONE, NO_WALL_FUNCTION )
%
% Marker(s) of the surface where custom thermal BC's are defined.
MARKER_PYTHON_CUSTOM = ( NONE )
%
% Marker(s) of the surface where obj. func. (design problem) will be evaluated
MARKER_DESIGNING = ( OUT )
%
% Marker(s) of the surface that is going to be analyzed in detail (massflow, average pressure, distortion, etc)
MARKER_ANALYZE = ( OUT )
%
% Method to compute the average value in MARKER_ANALYZE (AREA, MASSFLUX).
MARKER_ANALYZE_AVERAGE = MASSFLUX
%
% ----------------------------------- END -------------------------------------%

% ----------------------- GEOMETRY EVALUATION PARAMETERS ----------------------%
%
% Marker(s) of the surface where geometrical based function will be evaluated
GEO_MARKER= ( NONE )
%
% Description of the geometry to be analyzed (AIRFOIL, WING)
GEO_DESCRIPTION= AIRFOIL
%
% Coordinate of the stations to be analyzed
GEO_LOCATION_STATIONS= (0.0, 0.5, 1.0)
%
% Geometrical bounds (Y coordinate) for the wing geometry analysis or
% fuselage evaluation (X coordinate)
GEO_BOUNDS= (1.5, 3.5)
%
% Plot loads and Cp distributions on each airfoil section
GEO_PLOT_STATIONS= NO
%
% Number of section cuts to make when calculating wing geometry
GEO_NUMBER_STATIONS= 25
%
% Geometrical evaluation mode (FUNCTION, GRADIENT)
GEO_MODE= FUNCTION
%
% ----------------------------------- END -------------------------------------%

% ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
%
% Numerical method for spatial gradients (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES)
NUM_METHOD_GRAD= GREEN_GAUSS
%
% CFL number (initial value for the adaptive CFL number)
CFL_NUMBER= 1
%
% 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= ( 1.5, 0.5, 1.25, 50.0 )
%
% Maximum Delta Time in local time stepping simulations
MAX_DELTA_TIME= 1E6
%
% Runge-Kutta alpha coefficients
RK_ALPHA_COEFF= ( 0.66667, 0.66667, 1.000000 )
%
% -- OBJECTIVE_FUNCTION -- and -- OBJECTIVE_WEIGHT -- have been traslated to the end cfg option
%
% ----------------------------------- END -------------------------------------%


% ----------- SLOPE LIMITER AND DISSIPATION SENSOR DEFINITION -----------------%
%
% 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= VENKATAKRISHNAN
%
% Monotonic Upwind Scheme for Conservation Laws (TVD) in the turbulence equations.
% Required for 2nd order upwind schemes (NO, YES)
MUSCL_TURB= NO
%
% Slope limiter (NONE, VENKATAKRISHNAN, VENKATAKRISHNAN_WANG,
% BARTH_JESPERSEN, VAN_ALBADA_EDGE)
SLOPE_LIMITER_TURB= VENKATAKRISHNAN
%

% Coefficient for the Venkat's limiter (upwind scheme). A larger values decrease
% the extent of limiting, values approaching zero cause
% lower-order approximation to the solution (0.05 by default)
VENKAT_LIMITER_COEFF= 0.05
%
% Coefficient for the adjoint sharp edges limiter (3.0 by default).
% ADJ_SHARP_LIMITER_COEFF= 3.0
%
% Freeze the value of the limiter after a number of iterations
LIMITER_ITER= 999999
%

% 1st order artificial dissipation coefficients for
% the Lax–Friedrichs method ( 0.15 by default )
LAX_SENSOR_COEFF= 0.15
%
% 2nd and 4th order artificial dissipation coefficients for
% the JST method ( 0.5, 0.02 by default )
JST_SENSOR_COEFF= ( 0.5, 0.02 )
%
% 1st order artificial dissipation coefficients for
% the adjoint Lax–Friedrichs method ( 0.15 by default )
% ADJ_LAX_SENSOR_COEFF= 0.15
%
% 2nd, and 4th order artificial dissipation coefficients for
% the adjoint JST method ( 0.5, 0.02 by default )
% ADJ_JST_SENSOR_COEFF= ( 0.5, 0.02 )
%
% ----------------------------------- END -------------------------------------%


% ------------------------ LINEAR SOLVER DEFINITION ---------------------------%
%
% Linear solver or smoother for implicit formulations (BCGSTAB, FGMRES, SMOOTHER_JACOBI,
% SMOOTHER_ILU, SMOOTHER_LUSGS,
% SMOOTHER_LINELET)
%LINEAR_SOLVER= FGMRES
%
% Preconditioner of the Krylov linear solver (ILU, LU_SGS, LINELET, JACOBI)
%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-6
%
% Max number of iterations of the linear solver for the implicit formulation
%LINEAR_SOLVER_ITER= 5
%
% ----------------------------------- END -------------------------------------%


% -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------%
%
% Convective numerical method (JST, JST_KE, JST_MAT, LAX-FRIEDRICH, CUSP, ROE, AUSM,
% AUSMPLUSUP, AUSMPLUSUP2, AUSMPLUSM, HLLC, TURKEL_PREC,
% SW, MSW, FDS, SLAU, SLAU2, L2ROE, LMROE)
CONV_NUM_METHOD_FLOW= ROE
%
% Roe Low Dissipation function for Hybrid RANS/LES simulations (FD, NTS, NTS_DUCROS)
ROE_LOW_DISSIPATION= FD
%
% Post-reconstruction correction for low Mach number flows (NO, YES)
LOW_MACH_CORR= NO
%
% Roe-Turkel preconditioning for low Mach number flows (NO, YES)
LOW_MACH_PREC= NO
%
% Entropy fix coefficient (0.0 implies no entropy fixing, 1.0 implies scalar
% artificial dissipation)
ENTROPY_FIX_COEFF= 0.0
%
% Time discretization (RUNGE-KUTTA_EXPLICIT, EULER_IMPLICIT, EULER_EXPLICIT)
TIME_DISCRE_FLOW= EULER_IMPLICIT
%
% Relaxation coefficient
RELAXATION_FACTOR_ADJOINT= 0.95
%
% ----------------------------------- END -------------------------------------%


% -------------------- TURBULENT NUMERICAL METHOD DEFINITION ------------------%
%
% Convective numerical method (SCALAR_UPWIND)
CONV_NUM_METHOD_TURB= SCALAR_UPWIND
%
% Time discretization (EULER_IMPLICIT)
TIME_DISCRE_TURB= EULER_IMPLICIT
%
% Reduction factor of the coefficient in the turbulence problem
CFL_REDUCTION_TURB= 1.0
%
%
% ----------------------------------- END -------------------------------------%


% --------------------------- CONVERGENCE PARAMETERS --------------------------%
%
CONV_RESIDUAL_MINVAL= -10
CONV_STARTITER= 0
CONV_CAUCHY_ELEMS= 100
CONV_CAUCHY_EPS= 0.1
%
% ----------------------------------- END -------------------------------------%


OUTPUT_FILES= (RESTART, TECPLOT,TECPLOT_ASCII, SURFACE_CSV )
% list of writing frequencies corresponding to the list in OUTPUT_FILES
OUTPUT_WRT_FREQ= (500,200, 200, 500 )
%
HISTORY_WRT_FREQ_OUTER= 1
%
HISTORY_WRT_FREQ_TIME= 1

% ------------------------- INPUT/OUTPUT INFORMATION --------------------------%
%
% Mesh input file
MESH_FILENAME= inlet.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, STL)
TABULAR_FORMAT= TECPLOT
%
% Output file convergence history (w/o extension)
CONV_FILENAME= history
%
% Output file restart flow
RESTART_FILENAME= restart_flow.dat
%
% Output file restart adjoint
RESTART_ADJ_FILENAME= restart_adj.dat
%
% Output file flow (w/o extension) variables
VOLUME_FILENAME= flow
VOLUME_OUTPUT=(COORDINATES, SOLUTION, PRIMITIVE, MEAN_DENSITY, MEAN_VELOCITY-X, MEAN_VELOCITY-Y, MEAN_VELOCITY-Z, MEAN_PRESSURE)
%
% Output file adjoint (w/o extension) variables
VOLUME_ADJ_FILENAME= adjoint
%
% Output objective function gradient (using continuous adjoint)
GRAD_OBJFUNC_FILENAME= of_grad.dat
%
% Output file surface flow coefficient (w/o extension)
SURFACE_FILENAME= surface_flow
%
% Output file surface adjoint coefficient (w/o extension)
SURFACE_ADJ_FILENAME= surface_adjoint
%
%
% Screen output
SCREEN_OUTPUT=(TIME_ITER, INNER_ITER, LIFT, DRAG, TOTAL_HEATFLUX, SURFACE_STATIC_PRESSURE, MACH)
%
% History output groups (use 'SU2_CFD -d <config_file>' to view list of available fields)
HISTORY_OUTPUT= (ITER, SURFACE_MACH, SURFACE_MASSFLOW, SURFACE_STATIC_PRESSURE, MACH )
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