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Old   July 7, 2022, 04:21
Post Central Scheme vs Upwind Scheme
  #1
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Praveen
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Hello, I am write now working on a project of creating SU2 Configuration files from XML documents.
I recently generated SU2 configuration file for Lid Driven Cavity flow. I have attached the config file I generated. Input/ Output information I have added while running the case.
So the problem is,
The case is for Incompressible fluid, So in SU2 the numerical Schemes available are either JST, LAX-FRIEDRICH or FDS. In which the previous two being Central schemes and the last one is Upwind scheme.
My case runs fine for Upwind scheme but it does not run for Central Schemes.
I am getting the following error:
"Error in "void CSolver::SetResidual_RMS(const CGeometry*, const CConfig*)":
-------------------------------------------------------------------------
SU2 has diverged (NaN detected)."

It runs fine for FDS(Upwind scheme) but as soon as I change solver to JST or LAX-FRIEDRICH (Central schemes) it doesn't run anymore.
Here is my cfg file:
Quote:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% SU2 configuration file %
% Case description: __________________________________________________ _______ %
% Author: __________________________________________________ _________________ %
% Institution: __________________________________________________ ____________ %
% Date: __________ %
% File Version 7.3.1 "Blackbird" %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------%
%
SOLVER= INC_NAVIER_STOKES
%
% Specify turbulent model (NONE, SA, SA_NEG, SST)
KIND_TURB_MODEL= NONE
%
% Mathematical problem (DIRECT, CONTINUOUS_ADJOINT)
MATH_PROBLEM= DIRECT
%
% Restart solution (NO, YES)
RESTART_SOL= NO
%
REYNOLDS_LENGTH = 0.1
%-------------------- INCOMPRESSIBLE FREE STREAM CONDITIONS ------------------%
% Initial density for incompressible flows
% (1.2886 kg/m^3 by default (air), 998.2 Kg/m^3 (water))
INC_DENSITY_INIT= 998.2
%
% Initial velocity for incompressible flows (1.0,0,0 m/s by default)
INC_VELOCITY_INIT= (0.0 0.0 0.0)
%
% Free-stream viscosity
FREESTREAM_VISCOSITY= 9.982
%
% --------------------------- VISCOSITY MODEL ---------------------------------%
%
% Viscosity model (SUTHERLAND, CONSTANT_VISCOSITY).
VISCOSITY_MODEL= CONSTANT_VISCOSITY
%
% Molecular Viscosity that would be constant (1.716E-5 by default)
MU_CONSTANT= 9.982
%
% ---------------------- REFERENCE VALUE DEFINITION ---------------------------%
INC_NONDIM= REFERENCE_VALUES
% Reference density for incompressible flows (1.0 kg/m^3 by default)
INC_DENSITY_REF= 998.2
%
% Reference velocity for incompressible flows (1.0 m/s by default)
INC_VELOCITY_REF= 1.0
%
% -------------------- BOUNDARY CONDITION DEFINITION --------------------------%
% Navier-Stokes (no-slip), constant heat flux wall marker(s) (NONE = no marker)
% Format: ( marker name, constant heat flux (J/m^2), ... )
MARKER_HEATFLUX= (fixedWalls, 0.0, movingWall, 0.0, )
%
MARKER_SYM= (frontAndBack, )
%
% Marker(s) of the surface to be plotted or designed
MARKER_PLOTTING= (movingWall, fixedWalls, )
%
% Marker(s) of the surface where the functional (Cd, Cl, etc.) will be evaluated
MARKER_MONITORING= (movingWall, fixedWalls, )
%
% ___________________ SOLVER CONTROL ____________________________________________%
% Convergence field
CONV_FIELD= RMS_VELOCITY-X
% Min value of the residual (log10 of the residual)
CONV_RESIDUAL_MINVAL= -12
%
% 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
%
% -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------%
%
% Convective numerical method (JST, LAX-FRIEDRICH, CUSP, ROE, AUSM, HLLC,
% TURKEL_PREC, MSW)
CONV_NUM_METHOD_FLOW= JST
%
% Monotonic Upwind Scheme for Conservation Laws (TVD) in the flow equations.
% Required for 2nd order upwind schemes (NO, YES)
MUSCL_FLOW= YES
%
% Slope limiter (VENKATAKRISHNAN, MINMOD)
SLOPE_LIMITER_FLOW= NONE
%
% 2nd and 4th order artificial dissipation coefficients
JST_SENSOR_COEFF= ( 0.0, 0.02 )
%
% Time discretization (RUNGE-KUTTA_EXPLICIT, EULER_IMPLICIT, EULER_EXPLICIT)
TIME_DISCRE_FLOW= EULER_IMPLICIT
%
% ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
%
% Numerical method for spatial gradients (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES)
NUM_METHOD_GRAD= GREEN_GAUSS
%
% Courant-Friedrichs-Lewy condition of the finest grid
CFL_NUMBER= 2.0
%
% 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, 1.0, 100.0 )
%
% Number of total iterations
ITER= 99999
%
% ------------------------ LINEAR SOLVER DEFINITION ---------------------------%
%
% Linear solver for the implicit (or discrete adjoint) formulation (BCGSTAB, FGMRES)
LINEAR_SOLVER= BCGSTAB
%
% Min error of the linear solver for the implicit formulation
LINEAR_SOLVER_ERROR= 1.0E-4
%
% Max number of iterations of the linear solver for the implicit formulation
LINEAR_SOLVER_ITER= 5
%
% ----------------------- DYNAMIC MESH DEFINITION -----------------------------%
%
% Type of dynamic mesh (NONE, RIGID_MOTION, DEFORMING, ROTATING_FRAME,
% MOVING_WALL, AEROELASTIC, ELASTICITY, EXTERNAL)
SURFACE_MOVEMENT= MOVING_WALL
%
% Motion mach number (non-dimensional). Used for initializing a viscous flow
% with the Reynolds number and for computing force coeffs. with dynamic meshes.
%MACH_MOTION= 0.1
%
% Moving wall boundary marker(s) (NONE = no marker, ignored for RIGID_MOTION)
MARKER_MOVING= ( movingWall )
%
% Translational velocity (m/s) in the x, y, & z directions
SURFACE_TRANSLATION_RATE= ( 1.0 0.0 0.0)
%
% ------------------------- INPUT/OUTPUT INFORMATION --------------------------%
%
% Mesh input file
MESH_FILENAME= cavityexboundary.su2
%
% Mesh input file format (SU2, CGNS, NETCDF_ASCII)
MESH_FORMAT= SU2
%
% 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
%
TABULAR_FORMAT= CSV
%
% 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
%
% 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
%
% Writing solution file frequency
OUTPUT_WRT_FREQ= 50
%
%
% Screen output
SCREEN_OUTPUT= (INNER_ITER, RMS_DENSITY, RMS_ENERGY, DRAG)
Can anyone tell me which value did I not initialize or if there is any mistake with my configuration file?? Any help is appreciated.
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Old   July 7, 2022, 17:54
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pcg
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Pedro Gomes
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Hi,
Try setting some initial velocity different from 0:
INC_VELOCITY_INIT= (0.0 1.0 0.0)
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