[Nicola_Fontana]

Hi everyone,
I would like to ask if anyone could help me or provide me general infromation about the settings of the configuration file for this two mesh. I already tried with different settings, but I can't get convergence in both case.
I can't figure out if the problem is in the boundary condition or in the setting of convergence criteria.

1. Subsonic Converging Nozzle
In this case I would like to simulate the subsonic flow throught the nozzle, including the outern region;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                              %
% SU2 configuration file                                                       %
% Case description: Air flow in converging nozzle                              %
%                                                                              %
% Author: Nicola Fontana                                                       %
% Institution:                                          %
% Date: 24.11.2021                                                             %
% File Version 7.2                                                             %
%                                                                              %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------%
%
% Physical governing equations (EULER, NAVIER_STOKES,
%                               FEM_EULER, FEM_NAVIER_STOKES, FEM_RANS, FEM_LES,
%                               WAVE_EQUATION, HEAT_EQUATION, FEM_ELASTICITY,
%                               POISSON_EQUATION)
%
%SOLVER = EULER
%
SOLVER= RANS
%
% Specify turbulence model (NONE, SA, SA_NEG, SST, SA_E, SA_COMP, SA_E_COMP)
KIND_TURB_MODEL= SA
%
% Mathematical problem (DIRECT, CONTINUOUS_ADJOINT, DISCRETE_ADJOINT)
MATH_PROBLEM= DIRECT
%
% Restart solution (NO, YES)
RESTART_SOL= NO
%
% 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
%
% -------------------- COMPRESSIBLE FREE-STREAM DEFINITION --------------------%
%
% Mach number (non-dimensional, based on the free-stream values)
MACH_NUMBER= 1E-9
%
% 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= 101300
%
% Free-stream temperature (288.15 K, 518.67 R by default)
FREESTREAM_TEMPERATURE= 290
%
% Compressible flow non-dimensionalization (DIMENSIONAL, FREESTREAM_PRESS_EQ_ONE,
%                              FREESTREAM_VEL_EQ_MACH, FREESTREAM_VEL_EQ_ONE)
%REF_DIMENSIONALIZATION= DIMENSIONAL
% Reynolds number (non-dimensional, based on the free-stream values)
%REYNOLDS_NUMBER= 540000
%
% Reynolds length (1 m, 1 inch by default)
REYNOLDS_LENGTH= 1

% -------------------- 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= ( wall, 0.0 )
%
% Symmetry boundary marker(s) (NONE = no marker)
MARKER_SYM= ( simmetry )
%
% Riemann boundary marker(s) (NONE = no marker)
% Format: (marker, data kind flag, list of data)
%MARKER_RIEMANN= ( farfield, TOTAL_CONDITIONS_PT, 101300, 298.15, 1.0, 0.0, 0.0, outlet, STATIC_PRESSURE, 100000, 0.0, 0.0, 0.0, 0.0 )

% Inlet boundary marker(s) (NONE = no marker) 
% Format: ( inlet marker, total temperature, total pressure, flow_direction_x,
%           flow_direction_y, flow_direction_z, ... ) where flow_direction is
%           a unit vector.
MARKER_INLET= ( farfield, 288.6, 103010.0, 1.0, 0.0, 0.0 )
%
% Outlet boundary marker(s) (NONE = no marker)
% Format: ( outlet marker, back pressure (static), ... )
MARKER_OUTLET= ( outlet, 101300.0 )
% ------------- 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= 0.1
%
% Adaptive CFL number (NO, YES)
%CFL_ADAPT= YES
%
% Parameters of the adaptive CFL number (factor down, factor up, CFL min value,
%                                        CFL max value )
%CFL_ADAPT_PARAM= ( 0.1, 2.0, 10.0, 1000.0 )
%
% Maximum Delta Time in local time stepping simulations
MAX_DELTA_TIME= 1E6

% ----------- 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= NONE
%
% Monotonic Upwind Scheme for Conservation Laws (TVD) in the turbulence equations.
%           Required for 2nd order upwind schemes (NO, YES)
%MUSCL_TURB= NO

% ------------------------ 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= ILU
%
% 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-10
%
% Max number of iterations of the linear solver for the implicit formulation
LINEAR_SOLVER_ITER= 20

% -------------------------- MULTIGRID PARAMETERS -----------------------------%
%
% Multi-grid levels (0 = no multi-grid)
MGLEVEL= 0

% -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------%
%
% Convective numerical method (JST, LAX-FRIEDRICH, CUSP, ROE, AUSM, AUSMPLUSUP, AUSMPLUSUP2, HLLC,
%                              TURKEL_PREC, MSW, FDS)
CONV_NUM_METHOD_FLOW= ROE
%
% Entropy fix coefficient (0.0 implies no entropy fixing, 1.0 implies scalar
%                          artificial dissipation)
%ENTROPY_FIX_COEFF= 0.1
%
% 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)
TIME_DISCRE_TURB= EULER_IMPLICIT
%
% Reduction factor of the CFL coefficient in the turbulence problem
CFL_REDUCTION_TURB= 1.0

% --------------------------- CONVERGENCE PARAMETERS --------------------------%
% Convergence field (see available fields with the -d flag at the command line)
%CONV_FIELD= RMS_DENSITY
%
% Number of total iterations
ITER= 5000
%
% Min value of the residual (log10 of the residual)
CONV_RESIDUAL_MINVAL= -10
%
% Start convergence criteria at iteration number
CONV_STARTITER= 10

% ------------------------- INPUT/OUTPUT INFORMATION --------------------------%
%
% Mesh input file
MESH_FILENAME= C_Nozzle_Curve.su2
%
% Mesh input file format (SU2, CGNS)
MESH_FORMAT= SU2
%
% Mesh output file
MESH_OUT_FILENAME= mesh_out.su2
%
% Restart flow input file
SOLUTION_FILENAME= solution_flow.dat
%
% Output file format (TECPLOT, TECPLOT_BINARY, PARAVIEW, PARAVIEW_BINARY,
%                     FIELDVIEW, FIELDVIEW_BINARY)
TABULAR_FORMAT= CSV
%
% Output file convergence history (w/o extension)
CONV_FILENAME= history
%
% 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
%
% Writing solution file frequency
OUTPUT_WRT_FREQ= 1000
%
% Screen output
SCREEN_OUTPUT= (INNER_ITER, RMS_DENSITY, RMS_TKE, RMS_DISSIPATION, LIFT, DRAG)

2. Supersonic Diverging Nozzle

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                              %
% SU2 configuration file                                                       %
% Case description: Supersonic isentropic nozzle flow                          %
%                                                                              %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------%
%
% Physical governing equations (EULER, NAVIER_STOKES,
%                               TNE2_EULER, TNE2_NAVIER_STOKES,
%                               WAVE_EQUATION, HEAT_EQUATION, LINEAR_ELASTICITY,
%                               POISSON_EQUATION)
SOLVER = EULER
%

%SOLVER= RANS
%
% Specify turbulence model (NONE, SA, SA_NEG, SST, SA_E, SA_COMP, SA_E_COMP)
%KIND_TURB_MODEL= SA

% Mathematical problem (DIRECT, ADJOINT, LINEARIZED)
MATH_PROBLEM = DIRECT

% Restart solution (NO, YES)
RESTART_SOL = NO

% -------------------- COMPRESSIBLE FARFIELD DEFINITION --------------------%

% Mach number (non-dimensional, based on the free-stream values)
MACH_NUMBER = 1.0

% Angle of attack (degrees, only for compressible flows)
AOA = 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 = 3697978.51402

% Free-stream temperature (288.15 K, 518.67 R by default)
FREESTREAM_TEMPERATURE = 3000

% Reynolds length (1 m by default)
REYNOLDS_LENGTH = 1.0

% ---------------------- 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

% ------------------------- IDEAL GAS PROPERTIES -----------------------------%

% Different gas model (STANDARD_AIR, IDEAL_GAS, VW_GAS, PR_GAS)
FLUID_MODEL = IDEAL_GAS

% 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, hardcoded for model STANDARD_AIR)
GAS_CONSTANT = 287.0

% -------------------- BOUNDARY CONDITION DEFINITION --------------------------%

% Euler wall boundary marker(s) (NONE = no marker)
MARKER_EULER = ( Nozzle )
% Riemann boundary marker(s) (NONE = no marker)

% Format: (marker, data kind flag, list of data)
MARKER_RIEMANN= ( Inlet, TOTAL_CONDITIONS_PT, 3697978.51402, 3000, 1.0, 0.0, 0.0, Outlet, STATIC_PRESSURE, 200000.0, 0.0, 0.0, 0.0, 0.0 )

% Farfield marker (NONE = no marker)
%MARKER_FAR = ( Inlet )

% Symmetry boundary marker(s) (NONE = no marker)
MARKER_SYM = ( Symmetry )

% Supersonic outlet boundary marker(s) (NONE = no marker)
%MARKER_SUPERSONIC_OUTLET = ( Outlet )

% ------------------------ SURFACES IDENTIFICATION ----------------------------%
% Marker(s) of the surface to be plotted or designed
MARKER_PLOTTING = ( Symmetry )

% Marker(s) of the surface where the functional (Cd, Cl, etc.) will be evaluated
MARKER_MONITORING = ( Nozzle, Symmetry )

% ------------- 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 = 15

% Adaptive CFL number (NO, YES)
%CFL_ADAPT = YES

% Parameters of the adaptive CFL number (factor down, factor up, CFL min value,
%                                        CFL max value )
CFL_ADAPT_PARAM = ( 0.5, 1.5, 1.0, 100.0 )

% Runge-Kutta alpha coefficients
RK_ALPHA_COEFF = ( 0.66667, 0.66667, 1.000000 )

% Number of total iterations
ITER = 10000

%
OBJECTIVE_FUNCTION= DRAG

% ------------------------ 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 = JACOBI

% Minimum error of the linear solver for implicit formulations
LINEAR_SOLVER_ERROR = 1E-4

% Max number of iterations of the linear solver for the implicit formulation
LINEAR_SOLVER_ITER = 10

% -------------------------- MULTIGRID PARAMETERS -----------------------------%

% Multi-Grid Levels (0 = no multi-grid)
MGLEVEL = 2

% Multi-grid cycle (V_CYCLE, W_CYCLE, FULLMG_CYCLE)
MGCYCLE = V_CYCLE

% Multi-grid pre-smoothing level
MG_PRE_SMOOTH = ( 1, 2, 3, 3 )

% 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 = 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, BARTH_JESPERSEN)
SLOPE_LIMITER_FLOW = VENKATAKRISHNAN

% Coefficient for the limiter (smooth regions)
VENKAT_LIMITER_COEFF = 100.0

% 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

% --------------------------- CONVERGENCE PARAMETERS --------------------------%

% Convergence criteria (CAUCHY, RESIDUAL)
CONV_CRITERIA = RESIDUAL

% 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-6

% ------------------------- INPUT/OUTPUT INFORMATION --------------------------%

% Mesh input file
MESH_FILENAME = SD_Nozzle_Coarse.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 = restart.dat

% Output file format (CSV, TECPLOT)
TABULAR_FORMAT = CSV

% Output file convergence history (w/o extension) 
CONV_FILENAME = history

% Output file restart flow
RESTART_FILENAME = restart.dat

% Output file flow (w/o extension) variables
VOLUME_FILENAME = Flow_Sup

% Output file surface flow coefficient (w/o extension)
SURFACE_FILENAME = surface

% Writing solution file frequency
OUTPUT_WRT_FREQ = 500

Thank you in advance for the replies,

Nicola