CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > SU2

Help wanted on SU2 Unsteady FSI

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 30, 2020, 04:51
Default Help wanted on SU2 Unsteady FSI
  #1
New Member
 
California
Join Date: Jan 2019
Posts: 15
Rep Power: 7
lalatuobu is on a distinguished road
Hi,

I was trying to do a unsteady fsi problem in SU2. Before unsteady simulation, I had issues for the steady solution. I was basically following the fsi steady tutorial in the SU2 tutorial except I re-created my own mesh in Pointwise, and changed some BCs and material properties to mimic my application.

https://su2code.github.io/tutorials/Static_FSI/



However, I always get the following error code after executing few outer iterations.


Error in "void CSysSolve<double>::ModGramSchmidt(int, vector<vector<ScalarType> > &, vector<CSysVector<ScalarType> > &) const [ScalarType = double]":
-------------------------------------------------------------------------
FGMRES orthogonalization failed, linear solver diverged.
------------------------------ Error Exit -------------------------------



I printed out the inner-loop output, it seems that the problem lies in the structural linear solver. After few iterations, the screen output become:


# CG residual history
# Residual tolerance target = 1e-08
# Initial residual norm = 653.158
0 2.22439
10 0.00436788
20 0.00105218
30 0.000474043
40 0.000183201
50 6.82945e-05
60 3.57483e-05
70 1.84961e-05
80 9.06388e-06
90 3.03924e-06
100 1.05806e-06
110 2.90883e-07
120 8.66932e-08
130 2.04726e-08
# CG final (true) residual:
# Iteration = 135: |res|/|res0| = 9.50867e-09.

+----------------------------------------------------------------+
| Zone 0 (Incomp. Fluid) |
+----------------------------------------------------------------+
| Outer_Iter| Inner_Iter| rms[P]| rms[U]| rms[V]|
+----------------------------------------------------------------+
| 9| 0| -3.142056| -1.707746| -1.821803|
| 9| 20| -3.642543| -1.759277| -1.855988|
| 9| 40| -3.677550| -1.758297| -1.872853|
| 9| 60| -3.717325| -1.741693| -1.868771|
| 9| 80| -3.744304| -1.718225| -1.866626|
| 9| 100| -3.726701| -1.691568| -1.868913|
| 9| 120| -3.709504| -1.663673| -1.851842|
| 9| 140| -3.684008| -1.629814| -1.835092|
| 9| 160| -3.653019| -1.596141| -1.812889|
| 9| 180| -3.624896| -1.563961| -1.783655|
| 9| 200| -3.592057| -1.536577| -1.755740|
| 9| 220| -3.552223| -1.517839| -1.720308|
| 9| 240| -3.543369| -1.492790| -1.688864|
| 9| 260| -3.538167| -1.468293| -1.663987|
| 9| 280| -3.550885| -1.444629| -1.647335|
| 9| 300| -3.580128| -1.427568| -1.630473|
| 9| 320| -3.595646| -1.417964| -1.616398|
| 9| 340| -3.602372| -1.407468| -1.618355|
| 9| 360| -3.609427| -1.393281| -1.637197|
| 9| 380| -3.604804| -1.379942| -1.666958|
| 9| 400| -3.612665| -1.367395| -1.695200|
| 9| 420| -3.613693| -1.360901| -1.712291|
| 9| 440| -3.601209| -1.361126| -1.710941|
| 9| 460| -3.580616| -1.364588| -1.697890|
| 9| 480| -3.560080| -1.369603| -1.685052|
| 9| 500| -3.545734| -1.374779| -1.681143|
| 9| 520| -3.541468| -1.380101| -1.674003|
| 9| 540| -3.542229| -1.384182| -1.663407|
| 9| 560| -3.541609| -1.385249| -1.659417|
| 9| 580| -3.532399| -1.385980| -1.666169|
| 9| 600| -3.520539| -1.389261| -1.677467|
| 9| 620| -3.516180| -1.395652| -1.681080|
| 9| 640| -3.521221| -1.403373| -1.673044|
| 9| 660| -3.530227| -1.409500| -1.664122|
| 9| 680| -3.534119| -1.412020| -1.668841|
| 9| 700| -3.536955| -1.409113| -1.683965|
| 9| 720| -3.539968| -1.400793| -1.703749|
| 9| 740| -3.544609| -1.388075| -1.713818|
| 9| 760| -3.553732| -1.372998| -1.699195|
| 9| 780| -3.566625| -1.357649| -1.670340|
| 9| 800| -3.582853| -1.341852| -1.646002|
| 9| 820| -3.598614| -1.324911| -1.635735|
| 9| 840| -3.609240| -1.305784| -1.637410|
| 9| 860| -3.619109| -1.282653| -1.638490|
| 9| 880| -3.633452| -1.256368| -1.628953|
| 9| 900| -3.650786| -1.230435| -1.605689|
| 9| 920| -3.662310| -1.205930| -1.578776|
| 9| 940| -3.658838| -1.181203| -1.564011|
| 9| 960| -3.648898| -1.154774| -1.559276|
| 9| 980| -3.647128| -1.126993| -1.549837|
| 9| 999| -3.655594| -1.101131| -1.530044|
+-----------------------------------------------------------------------------+
| Zone 1 (Structure) |
+-----------------------------------------------------------------------------+
| Outer_Iter| Inner_Iter| rms[U]| rms[R]| rms[E]| VonMises|
+-----------------------------------------------------------------------------+
| 9| 0| -0.176796| 4.192294| 2.453922| 2.8349e+05|

Incremental load: increment 1
+-----------------------------------------------------------------------------+
| Zone 1 (Structure) |
+-----------------------------------------------------------------------------+
| Outer_Iter| Inner_Iter| rms[U]| rms[R]| rms[E]| VonMises|
+-----------------------------------------------------------------------------+
| 9| 0| -0.268120| 2.584196| 1.413370| 5.0003e+04|
| 9| 10| nan| nan| nan| 0.0000e+00|
| 9| 20| nan| nan| nan| 0.0000e+00|
| 9| 30| nan| nan| nan| 0.0000e+00|
| 9| 40| nan| nan| nan| 0.0000e+00|
| 9| 50| nan| nan| nan| 0.0000e+00|
| 9| 60| nan| nan| nan| 0.0000e+00|
| 9| 70| nan| nan| nan| 0.0000e+00|
| 9| 80| nan| nan| nan| 0.0000e+00|
| 9| 90| nan| nan| nan| 0.0000e+00|
| 9| 99| nan| nan| nan| 0.0000e+00|

Incremental load: increment 2

Notice that I was using incremental loading condition to resolve the large deformation issue. I tried to change FGMRES settings but none of these setting could help to resolve the issue.
I also checked the flow field and deformation before exploding, and it seems reasonable to me (see attachment). I was using INC-NS



I wonder if anyone can help me to take a look into this issue?



btw: here is the config file used:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 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 = (config_channel.cfg, config_cantilever.cfg)

RESTART_SOL = NO
RESTART_ITER = 1

%%%%%%%%%%%%%%%%%%%%%%%
% SOLUTION STRATEGY
%%%%%%%%%%%%%%%%%%%%%%%
TIME_DOMAIN = NO

%TIME_MARCHING = DUAL_TIME_STEPPING-1ST_ORDER

%TIME_STEP = 5e-3

%TIME_ITER = 10

INNER_ITER = 500

%TIME_DISCRE_FLOW = EULER_IMPLICIT

MULTIZONE_SOLVER = BLOCK_GAUSS_SEIDEL
OUTER_ITER = 20

%%%%%%%%%%%%%%%%%%%%%%%
% COUPLING CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%

MARKER_ZONE_INTERFACE = (wet, wets)

%%%%%%%%%%%%%%%%%%%%%%%
% CONVERGENCE CRITERIA
%%%%%%%%%%%%%%%%%%%%%%%

CONV_FIELD = AVG_BGS_RES[0], AVG_BGS_RES[1]
CONV_RESIDUAL_MINVAL = -5

%%%%%%%%%%%%%%%%%%%%%%%
% 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)
SOLUTION_FILENAME = restart_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 = NO
CONV_FILENAME= history

***********************************************
***********************************************
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% SU2 configuration file %
% Case description: FSI: Vertical Cantilever in Channel - Flow %
% Author: Ruben Sanchez Fernandez %
% Institution: TU Kaiserslautern %
% Date: 2020-02-05 %
% File Version 7.0.2 "Blackbird" %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%
% SOLVER TYPE
%%%%%%%%%%%%%%%%%%%%%%%

SOLVER = INC_NAVIER_STOKES

%%%%%%%%%%%%%%%%%%%%%%%
% FLOW PROPERTIES
%%%%%%%%%%%%%%%%%%%%%%%

INC_NONDIM = INITIAL_VALUES
INC_DENSITY_MODEL = CONSTANT

INC_DENSITY_INIT = 1.28
INC_TEMPERATURE_INIT = 300
INC_VELOCITY_INIT = ( 10.0, 0.0, 0.0 )

INC_DENSITY_REF = 1.0
INC_VELOCITY_REF = 1.0
INC_TEMPERATURE_REF = 1.0

VISCOSITY_MODEL = CONSTANT_VISCOSITY
MU_CONSTANT = 16.82e-6
MU_REF= 1.716E-5
FREESTREAM_VISCOSITY= 1.853E-5


%%%%%%%%%%%%%%%%%%%%%%%
% INPUT
%%%%%%%%%%%%%%%%%%%%%%%

MESH_FORMAT = SU2
MESH_FILENAME = flowfield.su2

%%%%%%%%%%%%%%%%%%%%%%%
% BOUNDARY CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%




MARKER_HEATFLUX = ( wet, 0.0, base, 0.0)
MARKER_EULER = (ff)
INC_INLET_TYPE = VELOCITY_INLET
INC_OUTLET_TYPE = PRESSURE_OUTLET

MARKER_INLET = ( inlet, 0.0, 10.0, 1.0, 0.0, 0.0 )
MARKER_OUTLET = ( outlet, 0.0 )

MARKER_MONITORING = ( wet )

%%%%%%%%%%%%%%%%%%%%%%%
% COUPLING CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%

MARKER_FLUID_LOAD = ( wet )

DEFORM_MESH = YES
MARKER_DEFORM_MESH = ( wet )

DEFORM_STIFFNESS_TYPE = WALL_DISTANCE
DEFORM_LINEAR_SOLVER = CONJUGATE_GRADIENT
DEFORM_LINEAR_SOLVER_PREC = ILU
DEFORM_LINEAR_SOLVER_ERROR = 1E-8
DEFORM_LINEAR_SOLVER_ITER = 2000
DEFORM_CONSOLE_OUTPUT = YES

%%%%%%%%%%%%%%%%%%%%%%%
% SOLUTION METHOD
%%%%%%%%%%%%%%%%%%%%%%%


INNER_ITER = 1000


%%%%%%%%%%%%%%%%%%
% NUMERICAL METHODS
%%%%%%%%%%%%%%%%%%%

NUM_METHOD_GRAD = WEIGHTED_LEAST_SQUARES
CFL_NUMBER = 3

CONV_NUM_METHOD_FLOW = FDS
MUSCL_FLOW = YES
SLOPE_LIMITER_FLOW = NONE

%%%%%%%%%%%%%%%%%%%%%%%
% REFERCENCE VALUES
%%%%%%%%%%%%%%%%%%%%%%%

REF_ORIGIN_MOMENT_X = 0.00
REF_ORIGIN_MOMENT_Y = 0.00
REF_ORIGIN_MOMENT_Z = 0.00

REF_LENGTH = 0.01
REF_AREA = 0.01

%%%%%%%%%%%%%%%%%%%%%%%
% CONVERGENCE CRITERIA
%%%%%%%%%%%%%%%%%%%%%%%

CONV_CRITERIA = RESIDUAL
CONV_FIELD = RMS_PRESSURE, RMS_VELOCITY-X, RMS_VELOCITY-Y, FORCE-X, FORCE-Y
CONV_RESIDUAL_MINVAL = -12

CONV_STARTITER = 10
CONV_CAUCHY_ELEMS = 100
CONV_CAUCHY_EPS = 1E-6

%%%%%%%%%%%%%%%%%%%%%%%
% LINEAR SOLVER
%%%%%%%%%%%%%%%%%%%%%%%

LINEAR_SOLVER = FGMRES
LINEAR_SOLVER_PREC = ILU
LINEAR_SOLVER_ERROR = 1E-10
LINEAR_SOLVER_ITER = 1000

SCREEN_WRT_FREQ_INNER = 20

****************************************
****************************************
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 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 = 0.5E6
POISSON_RATIO = 0.49
FORMULATION_ELASTICITY_2D = PLANE_STRAIN

%%%%%%%%%%%%%%%%%%%%%%%
% INPUT
%%%%%%%%%%%%%%%%%%%%%%%

MESH_FORMAT = SU2
MESH_FILENAME = structure.su2

%%%%%%%%%%%%%%%%%%%%%%%
% BOUNDARY CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%

MARKER_CLAMPED = ( base )
MARKER_PRESSURE = ( wets, 0)

%%%%%%%%%%%%%%%%%%%%%%%
% COUPLING CONDITIONS
%%%%%%%%%%%%%%%%%%%%%%%

MARKER_FLUID_LOAD = ( wets )

%%%%%%%%%%%%%%%%%%%%%%%
% SOLUTION METHOD
%%%%%%%%%%%%%%%%%%%%%%%

NONLINEAR_FEM_SOLUTION_METHOD = NEWTON_RAPHSON


INNER_ITER = 100


INCREMENTAL_LOAD = YES
NUMBER_INCREMENTS = 40
INCREMENTAL_CRITERIA = (2.0, 2.0, 2.0)



%%%%%%%%%%%%%%%%%%%%%%%
% 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_WRT_FREQ_INNER = 20
Attached Images
File Type: jpg Screen Shot 2020-06-30 at 3.46.39 PM.jpg (36.9 KB, 26 views)
lalatuobu is offline   Reply With Quote

Reply

Tags
fsi 2-way coupling, su2 edu, su2 examples

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Problem with restart in FSI unsteady simulation david_mocholi SU2 1 June 24, 2023 07:06
CGNS Boundary conditions using SU2 denzell SU2 3 July 9, 2018 06:58
VTK Error For Unsteady SU2 pbrady2013 SU2 2 May 24, 2018 23:05
The initialization of flow field for time accurate, unsteady simulation and BC zhengjg SU2 3 September 29, 2017 16:38
Welcome to the Stanford University Unstructured (SU2) forum! economon SU2 0 January 7, 2013 03:48


All times are GMT -4. The time now is 13:03.