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SU2 diverging for hypersonic flows

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Old   January 9, 2023, 13:51
Post SU2 diverging for hypersonic flows
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Praveen
Join Date: May 2022
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Hey,
I am currently trying to model a hypersonic flow around a double cone using SU2. I have set up the configuration file as shown below. I first tried with RANS keeping everything else same. It diverged and it didn't even produce proper shocks ( might be because it diverged very early). Then I tried to do the simulation with Euler. I tried both with turbulence and without turbulence. I am attaching the CFG file of turbulent case. I am not getting a converged solution with either case.
Same case was run on Ansys and we got the required results.(both in laminar and turbulent case) I don't have the mesh information right now.( But I will add pictures and screen out if necessary).
Can you please point out how I can improve the below CFG file so that it converges.
Quote:
%didn't specify reynolds length(to check)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% SU2 configuration file %
% Case description: __________________________________________________ _______ %
% Author: __________________________________________________ _________________ %
% Institution: __________________________________________________ ____________ %
% Date: __________ %
% File Version 7.4.0 "Blackbird" %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------%
%
% Solver type (EULER, NAVIER_STOKES, RANS,
% INC_EULER, INC_NAVIER_STOKES, INC_RANS,
% NEMO_EULER, NEMO_NAVIER_STOKES,
% FEM_EULER, FEM_NAVIER_STOKES, FEM_RANS, FEM_LES,
% HEAT_EQUATION_FVM, ELASTICITY)
SOLVER= EULER
%
% Specify turbulence model (NONE, SA, SST)
KIND_TURB_MODEL= SST
%
SST_OPTIONS= V2003m
%
MATH_PROBLEM= DIRECT
%
% Restart solution (NO, YES)
RESTART_SOL= NO
%
% -------------------- COMPRESSIBLE FREE-STREAM DEFINITION --------------------%
%
% Mach number (non-dimensional, based on the free-stream values)
MACH_NUMBER= 9.87
%
% Angle of attack (degrees, only for compressible flows)
AOA= 0.0
%
% 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= 49.53337
%
% Free-stream temperature (288.15 K, 518.67 R by default)
FREESTREAM_TEMPERATURE= 230
%
FREESTREAM_DENSITY = 0.00075
%
FREESTREAM_VISCOSITY = 1.7894E-05
% Reynolds number (non-dimensional, based on the free-stream values)
REYNOLDS_NUMBER= 1.524E4
%
% Free-stream velocity (1.0 m/s, 1.0 ft/s by default)
FREESTREAM_VELOCITY= ( 2999.842, 0.00, 0.00 )
%
% ---------------------- REFERENCE VALUE DEFINITION ---------------------------%
%
% Reference origin for moment computation (m or in)
REF_ORIGIN_MOMENT_X = 0.00
REF_ORIGIN_MOMENT_Y = 0.00
REF_ORIGIN_MOMENT_Z = 0.00
%
% Reference length for moment non-dimensional coefficients (m or in)
REF_LENGTH= 0
%
% Reference area for non-dimensional force coefficients (0 implies automatic
% calculation) (m^2 or in^2)
REF_AREA= 0
%
% -------------------- BOUNDARY CONDITION DEFINITION --------------------------%
% Navier-Stokes (no-slip), isothermal wall marker(s) (NONE = no marker)
% Format: ( marker name, constant wall temperature (K), ... )
MARKER_EULER= ( BASE, NOSE, CONE1, CONE2 )
%
% Far-field boundary marker(s) (NONE = no marker)
MARKER_FAR= ( DOMAIN )
%
% 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_SUPERSONIC_OUTLET= ( OUTLET )
MARKER_OUTLET= ( OUTLET, 49.53337 )
%
% Marker(s) of the surface in the surface flow solution file
MARKER_PLOTTING = ( BASE, NOSE, CONE1, CONE2 )
%
% Marker(s) of the surface where the non-dimensional coefficients are evaluated.
MARKER_MONITORING = ( BASE, NOSE, CONE1, CONE2 )
%
% ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
%
% Numerical method for spatial gradients (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES)
NUM_METHOD_GRAD= GREEN_GAUSS
% Numerical method for spatial gradients to be used for MUSCL reconstruction
% Options are (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES, LEAST_SQUARES). Default value is
% NONE and the method specified in NUM_METHOD_GRAD is used.
NUM_METHOD_GRAD_RECON = WEIGHTED_LEAST_SQUARES
%
% CFL number (initial value for the adaptive CFL number)
CFL_NUMBER= 0.01
%
% Adaptive CFL number (NO, YES)
CFL_ADAPT= NO
%
% Parameters of the adaptive CFL number (factor-down, factor-up, CFL min value,
% CFL max value, acceptable linear solver convergence)
% Local CFL increases by factor-up until max if the solution rate of change is not limited,
% and acceptable linear convergence is achieved. It is reduced if rate is limited, or if there
% is not enough linear convergence, or if the nonlinear residuals are stagnant and oscillatory.
% It is reset back to min when linear solvers diverge, or if nonlinear residuals increase too much.
CFL_ADAPT_PARAM= ( 0.1, 2.0, 0.01, 5, 0.001 )
% Monotonic Upwind Scheme for Conservation Laws (TVD) in the flow equations.
% Required for 2nd order upwind schemes (NO, YES)
MUSCL_FLOW= YES
%
% ------------------------ LINEAR SOLVER DEFINITION ---------------------------%
%
% Linear solver or smoother for implicit formulations:
% BCGSTAB, FGMRES, RESTARTED_FGMRES, CONJUGATE_GRADIENT (self-adjoint problems only), SMOOTHER.
LINEAR_SOLVER= BCGSTAB
%
% 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
%
ITER = 50000
% -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------%
%
% Convective numerical method (JST, JST_KE, JST_MAT, LAX-FRIEDRICH, CUSP, ROE, AUSM,
% AUSMPLUSUP, AUSMPLUSUP2, AUSMPWPLUS, HLLC, TURKEL_PREC,
% SW, MSW, FDS, SLAU, SLAU2, L2ROE, LMROE)
CONV_NUM_METHOD_FLOW= AUSM
%
% 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
%
% Time discretization (EULER_IMPLICIT, EULER_EXPLICIT)
TIME_DISCRE_TURB= EULER_IMPLICIT
%
% ------------------------------- SOLVER CONTROL ------------------------------%
%
% Convergence field
CONV_FIELD= RMS_DENSITY
%
% Min value of the residual (log10 of the residual)
CONV_RESIDUAL_MINVAL= -8
%
% 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-10
%
% ------------------------- SCREEN/HISTORY VOLUME OUTPUT --------------------------%
%
% Screen output fields (use 'SU2_CFD -d <config_file>' to view list of available fields)
SCREEN_OUTPUT= (INNER_ITER, RMS_DENSITY, RMS_MOMENTUM-X, RMS_MOMENTUM-Y, RMS_MOMENTUM-Z, LIFT, DRAG)
%
% History output groups (use 'SU2_CFD -d <config_file>' to view list of available fields)
HISTORY_OUTPUT= (ITER, RMS_RES)
%
% list of writing frequencies corresponding to the list in OUTPUT_FILES
OUTPUT_WRT_FREQ= 50
%
% Output the performance summary to the console at the end of SU2_CFD
WRT_PERFORMANCE= NO
%
% Overwrite or append iteration number to the restart files when saving
WRT_RESTART_OVERWRITE= YES
%
% Overwrite or append iteration number to the surface files when saving
WRT_SURFACE_OVERWRITE= YES
%
% Overwrite or append iteration number to the volume files when saving
WRT_VOLUME_OVERWRITE= YES
%
% ------------------------- INPUT/OUTPUT FILE INFORMATION --------------------------%
%
% Mesh input file
MESH_FILENAME= DoubleCone_10per.cgns
%
% Mesh input file format (SU2, CGNS)
MESH_FORMAT= CGNS
%
% Mesh output file
MESH_OUT_FILENAME= mesh_out.su2
%
% Restart flow input file
SOLUTION_FILENAME= solution_flow.dat
%
% Restart adjoint input file
SOLUTION_ADJ_FILENAME= solution_adj.dat
%
% Output tabular file format (TECPLOT, CSV)
TABULAR_FORMAT= CSV
%
% Files to output
% Possible formats : (TECPLOT_ASCII, TECPLOT, SURFACE_TECPLOT_ASCII,
% SURFACE_TECPLOT, CSV, SURFACE_CSV, PARAVIEW_ASCII, PARAVIEW_LEGACY, SURFACE_PARAVIEW_ASCII,
% SURFACE_PARAVIEW_LEGACY, PARAVIEW, SURFACE_PARAVIEW, RESTART_ASCII, RESTART, CGNS, SURFACE_CGNS, STL_ASCII, STL_BINARY)
% default : (RESTART, PARAVIEW, SURFACE_PARAVIEW)
OUTPUT_FILES= (RESTART, PARAVIEW, SURFACE_PARAVIEW)
%
% Output file convergence history (w/o extension)
CONV_FILENAME= history
%
% Output file with the forces breakdown
BREAKDOWN_FILENAME= forces_breakdown.dat
%
% 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
%
% Output file adjoint (w/o extension) variables
VOLUME_ADJ_FILENAME= adjoint
%
% Output Objective function
VALUE_OBJFUNC_FILENAME= of_eval.dat
%
% 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
%
% Read binary restart files (YES, NO)
READ_BINARY_RESTART= YES
%
% Reorient elements based on potential negative volumes (YES/NO)
REORIENT_ELEMENTS= YES
%
Any kind of help is appreciated.
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Old   January 10, 2023, 19:09
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Wally Maier
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Hi Praveen,

Can you post some images of the domain.
So other thoughts would be run the simulation 1st order first (MUSCL=NO). Additionally, I would suggest using the explicit solver. to start. Running with a CFL=0.01 using the implicit solver doesn't provide any benefit.

Best,
Wally
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