| sangeet |
April 1, 2021 14:31 |
Static FSI with Compressible Flow (SU2 7.1.1)
2 Attachment(s)
Hello,
I am currently running a static FSI case of supersonic flow over a compression ramp where the ramp is flexible (FEM grid with clamped-clamped boundary condition). The fluid only case (rigid ramp) converges well but when i try to run the coupled simulation, the structure's convergence is very poor. I tried both large and small deformations in the structural config file and I also tried plane stress and plain strain conditions. None of these cases showed any improvement.
The google drive link with config files and the grid files is
https://drive.google.com/drive/folde...7L?usp=sharing
I have also attached a picture of the grids for a quick idea.
Please kindly suggest on what I could be possibly doing wrong.
The fluid config file is
Code:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% SU2 configuration file %
% Case description: Supersonic flow over a wedge in a channel. %
% Author: Thomas D. Economon %
% Institution: Stanford University %
% Date: 2012.10.07 %
% File Version 5.0.0 "Raven" %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------%
%
% Physical governing equations (EULER, NAVIER_STOKES,
% WAVE_EQUATION, HEAT_EQUATION, FEM_ELASTICITY,
% POISSON_EQUATION)
SOLVER= RANS
%
% If Navier-Stokes, kind of turbulent model (NONE, SA)
KIND_TURB_MODEL= SST
%
% Mathematical problem (DIRECT, CONTINUOUS_ADJOINT)
MATH_PROBLEM= DIRECT
%
% Restart solution (NO, YES)
RESTART_SOL= NO
% ----------- COMPRESSIBLE AND INCOMPRESSIBLE FREE-STREAM DEFINITION ----------%
%
% Mach number (non-dimensional, based on the free-stream values)
MACH_NUMBER= 2.9
%
% Angle of attack (degrees)
AOA= 0.0
%
% Side-slip angle (degrees)
SIDESLIP_ANGLE= 0.0
%
% Free-stream temperature (288.15 K by default)
FREESTREAM_TEMPERATURE= 109.619686800895
%
% Reynolds number (non-dimensional, based on the free-stream values)
REYNOLDS_NUMBER= 148000
%
% Reynolds length (in meters)
REYNOLDS_LENGTH= 4.0454e-03
% ---------------------- REFERENCE VALUE DEFINITION ---------------------------%
%
% Reference origin for moment computation
REF_ORIGIN_MOMENT_X = 0.0
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= 1.0
% -------------------- BOUNDARY CONDITION DEFINITION --------------------------%
%
% Navier-Stokes wall boundary marker(s) (NONE = no marker)
MARKER_HEATFLUX= ( WALL1, 0.0, RAMP, 0.0, WALL2, 0.0 )
%
% Supersonic inlet boundary marker(s) (NONE = no marker)
% Total Conditions: (inlet marker, temperature, static pressure, velocity_x,
% velocity_y, velocity_z, ... ), i.e. all variables specified.
MARKER_SUPERSONIC_INLET= ( INLET, 109.619686800895, 13366.4283315982, 608.621433419003, 0.0, 0.0 )
%
% Outlet boundary marker(s) (NONE = no marker)
% Format: ( outlet marker, back pressure (static), ... )
MARKER_OUTLET= ( OUTLET, 10000, UPPER, 10000)
MARKER_SYM= ( SYM_PLANE )
%
% Marker(s) of the surface to be plotted or designed
MARKER_PLOTTING= ( WALL1, RAMP, WALL2 )
%
% Marker(s) of the surface where the functional (Cd, Cl, etc.) will be evaluated
MARKER_MONITORING= ( WALL1, RAMP, WALL2 )
% ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
%
% Numerical method for spatial gradients (GREEN_GAUSS, LEAST_SQUARES,
% WEIGHTED_LEAST_SQUARES)
NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
%
% Courant-Friedrichs-Lewy condition of the finest grid
CFL_NUMBER= 10
%
% 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, 1.5, 0.01, 1000 )
%
% Runge-Kutta alpha coefficients
RK_ALPHA_COEFF= ( 0.66667, 0.66667, 1.000000 )
%
% Number of total iterations
INNER_ITER= 100000
%
% Linear solver for the implicit formulation (BCGSTAB, FGMRES)
LINEAR_SOLVER= FGMRES
%
% Preconditioner of the Krylov linear solver (ILU, JACOBI, LINELET, LU_SGS)
LINEAR_SOLVER_PREC= ILU
%
% Min error of the linear solver for the implicit formulation
LINEAR_SOLVER_ERROR= 1E-6
%
% 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= 4
%
% Multi-grid cycle (V_CYCLE, W_CYCLE, FULLMG_CYCLE)
MGCYCLE= W_CYCLE
%
% Multi-grid pre-smoothing level
MG_PRE_SMOOTH= ( 1, 1, 1, 1 )
%
% 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= 0.5
%
% Damping factor for the correction prolongation
MG_DAMP_PROLONGATION= 0.5
% -------------------- 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 (NONE, VENKATAKRISHNAN, VENKATAKRISHNAN_WANG,
% BARTH_JESPERSEN, VAN_ALBADA_EDGE)
SLOPE_LIMITER_FLOW= NONE
%
% Coefficient for the limiter (smooth regions)
VENKAT_LIMITER_COEFF= 0.02
%
% 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
%
% Monotonic Upwind Scheme for Conservation Laws (TVD) in the turbulence equations.
% Required for 2nd order upwind schemes (NO, YES)
MUSCL_TURB= NO
%
% Slope limiter (VENKATAKRISHNAN, MINMOD)
SLOPE_LIMITER_TURB= VENKATAKRISHNAN
%
% Time discretization (EULER_IMPLICIT)
TIME_DISCRE_TURB= EULER_IMPLICIT
%%%%%%%%%%%%%%%%%%%%%%%
% COUPLING CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%
MARKER_FLUID_LOAD = ( RAMP )
DEFORM_MESH = YES
MARKER_DEFORM_MESH = ( RAMP )
DEFORM_STIFFNESS_TYPE = WALL_DISTANCE
DEFORM_LINEAR_SOLVER = CONJUGATE_GRADIENT
DEFORM_LINEAR_SOLVER_PREC = ILU
DEFORM_LINEAR_SOLVER_ERROR = 1E-10
DEFORM_LINEAR_SOLVER_ITER = 1000
DEFORM_CONSOLE_OUTPUT = NO
% --------------------------- CONVERGENCE PARAMETERS --------------------------%
%
% Convergence criteria (CAUCHY, RESIDUAL)
CONV_FIELD= RMS_DENSITY
%
% Min value of the residual (log10 of the residual)
CONV_RESIDUAL_MINVAL= -10
%
% 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
%--------------------------- HISTORY ------------------------------------------%
% History output groups (use 'SU2_CFD -d <config_file>' to view list of available fields)
HISTORY_OUTPUT= (ITER, RMS_RES, AERO_COEFF)
% ------------------------- INPUT/OUTPUT INFORMATION --------------------------%
%
% Mesh input file
MESH_FILENAME= Ramp25_Fine_0_5.cgns
%
% Mesh input file format (SU2, CGNS, NETCDF_ASCII)
MESH_FORMAT= CGNS
%
% Writing solution file frequency
OUTPUT_WRT_FREQ= 250
%
% Screen writing frequency
SCREEN_WRT_FREQ_INNER= 10
The structural config file is
Code:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% SU2 configuration file %
% Case description: FSI: Vertical Cantilever in Channel - Structure %
% Author: Ruben Sanchez Fernandez %
% Institution: TU Kaiserslautern %
% Date: 2020-02-05 %
% File Version 7.0.2 "Blackbird" %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%
% SOLVER TYPE
%%%%%%%%%%%%%%%%%%%%%%%
SOLVER = ELASTICITY
%%%%%%%%%%%%%%%%%%%%%%%
% STRUCTURAL PROPERTIES
%%%%%%%%%%%%%%%%%%%%%%%
GEOMETRIC_CONDITIONS = LARGE_DEFORMATIONS
MATERIAL_MODEL = NEO_HOOKEAN
ELASTICITY_MODULUS = 1.13E11
POISSON_RATIO = 0.37
FORMULATION_ELASTICITY_2D = PLANE_STRESS
%%%%%%%%%%%%%%%%%%%%%%%
% INPUT
%%%%%%%%%%%%%%%%%%%%%%%
MESH_FORMAT = SU2
MESH_FILENAME = ramp_slender_0_001.su2
%%%%%%%%%%%%%%%%%%%%%%%
% BOUNDARY CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%
MARKER_CLAMPED = ( LEFT_EDGE, RIGHT_EDGE )
MARKER_PRESSURE = ( LOWER_EDGE, 0)
%%%%%%%%%%%%%%%%%%%%%%%
% COUPLING CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%
MARKER_FLUID_LOAD = ( UPPER_EDGE )
%%%%%%%%%%%%%%%%%%%%%%%
% SOLUTION METHOD
%%%%%%%%%%%%%%%%%%%%%%%
NONLINEAR_FEM_SOLUTION_METHOD = NEWTON_RAPHSON
INNER_ITER = 40
%%%%%%%%%%%%%%%%%%%%%%%
% CONVERGENCE CRITERIA
%%%%%%%%%%%%%%%%%%%%%%%
CONV_FIELD = RMS_UTOL, RMS_RTOL, RMS_ETOL
CONV_RESIDUAL_MINVAL = -10
%%%%%%%%%%%%%%%%%%%%%%%
% LINEAR SOLVER
%%%%%%%%%%%%%%%%%%%%%%%
LINEAR_SOLVER = CONJUGATE_GRADIENT
LINEAR_SOLVER_PREC = ILU
LINEAR_SOLVER_ERROR = 1E-10
LINEAR_SOLVER_ITER = 1000
% Screen writing frequency
SCREEN_WRT_FREQ_INNER = 1
The FSI master config file is
Code:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% SU2 configuration file %
% Case description: FSI: Vertical Cantilever in Channel %
% Author: Ruben Sanchez Fernandez %
% Institution: TU Kaiserslautern %
% Date: 2020-02-05 %
% File Version 7.0.2 "Blackbird" %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%
% SOLVER TYPE
%%%%%%%%%%%%%%%%%%%%%%%
SOLVER = MULTIPHYSICS
%%%%%%%%%%%%%%%%%%%%%%%
% INPUT
%%%%%%%%%%%%%%%%%%%%%%%
MULTIZONE_MESH = NO
CONFIG_LIST = (flowSST.cfg, ramp.cfg)
%%%%%%%%%%%%%%%%%%%%%%%
% SOLUTION STRATEGY
%%%%%%%%%%%%%%%%%%%%%%%
MULTIZONE_SOLVER = BLOCK_GAUSS_SEIDEL
OUTER_ITER = 1000
%%%%%%%%%%%%%%%%%%%%%%%
% CONVERGENCE CRITERIA
%%%%%%%%%%%%%%%%%%%%%%%
CONV_FIELD = AVG_BGS_RES[0], AVG_BGS_RES[1]
CONV_RESIDUAL_MINVAL = -10
%%%%%%%%%%%%%%%%%%%%%%%
% Relaxation
%%%%%%%%%%%%%%%%%%%%%%%
%BGS_RELAXATION= FIXED_PARAMETER
%STAT_RELAX_PARAMETER= 0.8
%%%%%%%%%%%%%%%%%%%%%%%
% COUPLING CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%
MARKER_ZONE_INTERFACE = (RAMP, UPPER_EDGE)
%%%%%%%%%%%%%%%%%%%%%%%
% OUTPUT
%%%%%%%%%%%%%%%%%%%%%%%
SCREEN_OUTPUT = (OUTER_ITER, AVG_BGS_RES[0], AVG_BGS_RES[1], DEFORM_MIN_VOLUME[0], DEFORM_ITER[0])
WRT_ZONE_CONV = YES
OUTPUT_FILES = (RESTART, PARAVIEW, SURFACE_PARAVIEW, SURFACE_CSV)
SOLUTION_FILENAME = solution_fsi_steady
RESTART_FILENAME = restart_fsi_steady
VOLUME_FILENAME = fsi_steady
HISTORY_OUTPUT = ITER, BGS_RES[0], AERO_COEFF[0], BGS_RES[1]
WRT_ZONE_HIST = YES
CONV_FILENAME= history
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