[Creg]

Hello all,


I've recently started getting this error from a simulation and was wondering if anyone knows the cause?


Thanks in advance

[Creg]

% ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------%
%
% Physical governing equations (EULER, NAVIER_STOKES, NS_PLASMA)
%
SOLVER= RANS
%
% Specify turbulent model (NONE, SA, SA_NEG, SST)
KIND_TURB_MODEL= SA
%
% Mathematical problem (DIRECT, CONTINUOUS_ADJOINT)
MATH_PROBLEM= DIRECT
%
% ------------------------- UNSTEADY SIMULATION -------------------------------%
%
TIME_DOMAIN= YES
%
% Numerical Method for Unsteady simulation(NO, TIME_STEPPING, DUAL_TIME_STEPPING-1ST_ORDER, DUAL_TIME_STEPPING-2ND_ORDER, TIME_SPECTRAL)
TIME_MARCHING= DUAL_TIME_STEPPING-2ND_ORDER
%
% Time Step for dual time stepping simulations (s)
TIME_STEP= 1e-3
%
% Maximum Number of physical time steps.
TIME_ITER= 9999999
%
% Number of internal iterations (dual time method)
INNER_ITER= 9000
%
% -------------------- COMPRESSIBLE FREE-STREAM DEFINITION --------------------%
%
% Mach number (non-dimensional, based on the free-stream values)
MACH_NUMBER= 0.2
%
% Angle of attack (degrees, only for compressible flows)
AOA= 0.0
%
% De-Dimensionalization
REF_DIMENSIONALIZATION = DIMENSIONAL
%
% Free-stream temperature (288.15 K by default)
FREESTREAM_TEMPERATURE= 288.15
%
% Reynolds number (non-dimensional, based on the free-stream values)
REYNOLDS_NUMBER= 1.2e+6
%
% Reynolds length (1 m by default)
REYNOLDS_LENGTH= 1.0
%
% --------------------------- VISCOSITY MODEL ---------------------------------%
%
% Viscosity model (SUTHERLAND, CONSTANT_VISCOSITY).
VISCOSITY_MODEL= SUTHERLAND
%
% 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
%
% ---- IDEAL GAS, POLYTROPIC, VAN DER WAALS AND PENG ROBINSON CONSTANTS -------%
%
% Different gas model (STANDARD_AIR, IDEAL_GAS, VW_GAS, PR_GAS)
FLUID_MODEL= STANDARD_AIR
%
% Ratio of specific heats (1.4 default and the value is hardcoded
% for the model STANDARD_AIR)
GAMMA_VALUE= 1.4
%
% Specific gas constant (287.058 J/kg*K default and this value is hardcoded
% for the model STANDARD_AIR)
GAS_CONSTANT= 287.058
%
% ---------------------- REFERENCE VALUE DEFINITION ---------------------------%
%
% Reference origin for moment computation
REF_ORIGIN_MOMENT_X = 0.00
REF_ORIGIN_MOMENT_Y = 0.00
REF_ORIGIN_MOMENT_Z = 0.00
%
% Reference length for pitching, rolling, and yawing non-dimensional moment
REF_LENGTH= 1.0
%
% Reference area for force coefficients (0 implies automatic calculation)
REF_AREA= 0
%
% -------------------- BOUNDARY CONDITION DEFINITION --------------------------%
%
% Navier-Stokes wall boundary marker(s) (NONE = no marker)
MARKER_HEATFLUX= ( cylinder, 0.0 )
%
% Farfield boundary marker(s) (NONE = no marker)
MARKER_FAR= ( farfield )
%
% Marker(s) of the surface to be plotted or designed
MARKER_PLOTTING= ( cylinder )
%
% Marker(s) of the surface where the functional (Cd, Cl, etc.) will be evaluated
MARKER_MONITORING= ( cylinder )
%
% ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
%
% Numerical method for spatial gradients (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES)
NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
%
% Courant-Friedrichs-Lewy condition of the finest grid
CFL_NUMBER= 7
%
% 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= ( 0.5, 1, 1, 25 )
%
% Runge-Kutta alpha coefficients
RK_ALPHA_COEFF= ( 0.66667, 0.66667, 1.000000 )
%
% Linear solver for the implicit formulation (BCGSTAB, FGMRES)
LINEAR_SOLVER= FGMRES
%
LINEAR_SOLVER_PREC= ILU
%
LINEAR_SOLVER_ILU_FILL_IN= 0
%
LINEAR_SOLVER_SMOOTHER_RELAXATION= 1.0
%
% Min error of the linear solver for the implicit formulation
LINEAR_SOLVER_ERROR= 1E-3
%
% Max number of iterations of the linear solver for the implicit formulation
LINEAR_SOLVER_ITER= 10
%
% -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------%
%
% Convective numerical method (JST, LAX-FRIEDRICH, CUSP, ROE, AUSM, HLLC,
% TURKEL_PREC, MSW)
CONV_NUM_METHOD_FLOW= ROE
%
% Spatial numerical order integration (1ST_ORDER, 2ND_ORDER, 2ND_ORDER_LIMITER)
MUSCL_FLOW= NO
%
SLOPE_LIMITER_FLOW= VENKATAKRISHNAN
%
VENKAT_LIMITER_COEFF= 0.05
%
% 1st, 2nd and 4th order artificial dissipation coefficients
JST_SENSOR_COEFF= ( 0.5, 0.02 )
%
% 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
%
% Spatial numerical order integration (1ST_ORDER, 2ND_ORDER, 2ND_ORDER_LIMITER)
MUSCL_TURB= NO
%
% Slope limiter (NONE, VENKATAKRISHNAN, VENKATAKRISHNAN_WANG,
% BARTH_JESPERSEN, VAN_ALBADA_EDGE)
%
SLOPE_LIMITER_TURB= VENKATAKRISHNAN
%
% Time discretization (EULER_IMPLICIT)
TIME_DISCRE_TURB= EULER_IMPLICIT
%
% --------------------------- CONVERGENCE PARAMETERS --------------------------%
%
% Convergence criteria (CAUCHY, RESIDUAL)
CONV_CRITERIA = RESIDUAL
% Field to apply Cauchy Criterion to
CONV_FIELD= RMS_DENSITY
% Min value of the residual (log10 of the residual)
CONV_RESIDUAL_MINVAL= -6
%
%% Time convergence monitoring
WINDOW_CAUCHY_CRIT = YES
%
% List of time convergence fields
CONV_WINDOW_FIELD = (TAVG_DRAG, TAVG_LIFT)
%
% Time Convergence Monitoring starts at Iteration WINDOW_START_ITER + CONV_WINDOW_STARTITER
CONV_WINDOW_STARTITER = 0
%
% Epsilon to control the series convergence
CONV_WINDOW_CAUCHY_EPS = 1E-3
%
% Number of elements to apply the criteria
CONV_WINDOW_CAUCHY_ELEMS = 100
%
% Starting iteration for windowed-time-averaging
WINDOW_START_ITER = 100
%
% Window used for reverse sweep. Options (SQUARE, HANN, HANN_SQUARE, BUMP)
WINDOW_FUNCTION = HANN_SQUARE
%
% ------------------------- INPUT/OUTPUT INFORMATION --------------------------%
%
HISTORY_WRT_FREQ_INNER=0
SCREEN_WRT_FREQ_INNER =1
%
OUTPUT_FILES= CSV, PARAVIEW, SURFACE_PARAVIEW
%
% Mesh input file
MESH_FILENAME= cylinder.su2
%
% Mesh input file format (SU2, CGNS, NETCDF_ASCII)
MESH_FORMAT= SU2
%
% Mesh output file
MESH_OUT_FILENAME= mesh_out.su2
%
% Restart adjoint input file
SOLUTION_ADJ_FILENAME= restart_adj.dat
%
% Output file convergence history (w/o extension)
CONV_FILENAME= 0_history
%
% Output file format (PARAVIEW, TECPLOT, STL)
TABULAR_FORMAT= CSV
%
% 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 surface flow coefficient (w/o extension)
SURFACE_FILENAME= surface_flow
%
SCREEN_OUTPUT=(TIME_ITER, INNER_ITER, DRAG, LIFT, RMS_DENSITY, REL_RMS_DENSITY, CAUCHY_TAVG_DRAG, CAUCHY_TAVG_LIFT)
HISTORY_OUTPUT=(ITER,REL_RMS_RES,RMS_RES, AERO_COEFF,TAVG_AERO_COEFF, CAUCHY)
%

[bigfootedrockmidget]

so you did not get this error previously? What did you change? When you get this at the start of your run, something could be wrong with the initial solution of the problem, or You start with too aggressive settings. You could try lowering your CFL or your timestep