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Python-based Computational Python-based Computational Fluid-Structure InteractionsFluid-Structure Interactions
Dr.Raymond LeBeauDr.Raymond LeBeauDr.Suzanne Weaver SmithDr.Suzanne Weaver Smith
University of KentuckyUniversity of Kentucky&&
Dr.Thomas HauserDr.Thomas HauserUtah State UniversityUtah State University
Satish Kumar ChimakurthiMechanical Eng, University of Kentucky
Supported by KY NASA EPSCOR
Master’s thesis presentation – 6th of July 2004
Presentation OutlinePresentation Outline Motivation Motivation Physics of Rain-Wind induced vibrationsPhysics of Rain-Wind induced vibrations Goals of the projectGoals of the project Fluid-Structure InteractionsFluid-Structure Interactions FSI algorithmFSI algorithm Python related programming toolsPython related programming tools Python-enabled simulationPython-enabled simulation ResultsResults ConclusionsConclusions Future WorkFuture Work AcknowledgementsAcknowledgements
STIMULUS-ISTIMULUS-I Problems related to rain-wind induced vibrations in Problems related to rain-wind induced vibrations in
cable-stayed bridges remain unsolved till date. The cable-stayed bridges remain unsolved till date. The complex flow fields around inclined cables and the complex flow fields around inclined cables and the effect of rain added to that make the problem a grand effect of rain added to that make the problem a grand scientific and computational challengescientific and computational challenge
Rain-Wind Induced Vibrations (RWIV) in Cable-Stayed Rain-Wind Induced Vibrations (RWIV) in Cable-Stayed BridgesBridges
Peculiar vibration of cables in windy and rainy daysPeculiar vibration of cables in windy and rainy days Rivulets of water – upper and lower surfaces of the cableRivulets of water – upper and lower surfaces of the cable Rivulet changes cross section of the cableRivulet changes cross section of the cable Complex interaction between structure, wind, and rainComplex interaction between structure, wind, and rain Cable size and shape, wind speed, direction and turbulence, rain intensity, Cable size and shape, wind speed, direction and turbulence, rain intensity,
material repellency and roughness, cable weight, damping, and pre-strainmaterial repellency and roughness, cable weight, damping, and pre-strain Cable-water-rivulet interactionCable-water-rivulet interaction Rivulet is the key reason for the motion instability of the cableRivulet is the key reason for the motion instability of the cable
Photo courtesy: http://www.sri-hybrid.co.jp/en/civil/cable_damper.html
Meiko Nishi Bridge in Japan
Tacoma Narrows Bridge
RWIV VIDEO – COCHRANE BRIDGE (ALABAMA)
Movie courtesy: University of Wisconsin at Milwaukee
How to Model RWIV ?How to Model RWIV ?
All forces acting on the cableAll forces acting on the cable Forces on the upper water-rivuletForces on the upper water-rivulet Rivulet should be subjected to inertial and gravity forces, Rivulet should be subjected to inertial and gravity forces,
pressure gradients and air-water-cable frictionspressure gradients and air-water-cable frictions Fluid-Structure Interaction between cable and rivuletFluid-Structure Interaction between cable and rivulet Modeling these on a large-scale model experimentally, is Modeling these on a large-scale model experimentally, is
unrealisticunrealistic Computational methods are therefore, very crucial and Computational methods are therefore, very crucial and
indispensableindispensable
Goals of this ThesisGoals of this Thesis
Understand FSI (fluid-structure interaction) and the impact of Understand FSI (fluid-structure interaction) and the impact of rain-wind induced vibrations in cable-stayed bridgesrain-wind induced vibrations in cable-stayed bridges
Develop a loose coupling algorithm to automate the fluid-Develop a loose coupling algorithm to automate the fluid-structure interaction process with the help of software toolsstructure interaction process with the help of software tools
Simulate 2D FSI in the case of a simple harmonic oscillatorSimulate 2D FSI in the case of a simple harmonic oscillator
What is FSI ??What is FSI ??
FSI is a true Multiphysics phenomenon where a fluid FSI is a true Multiphysics phenomenon where a fluid flowing around or within a structure causes it to flowing around or within a structure causes it to move, spin or even change shape due to flow-induced move, spin or even change shape due to flow-induced pressure and shear loads – pressure and shear loads – ANSYS IncANSYS Inc
Fluid-structure interaction (FSI) scenarios are those Fluid-structure interaction (FSI) scenarios are those that involve the coupling of fluid mechanics and that involve the coupling of fluid mechanics and structural mechanicsstructural mechanics – – FLUENT IncFLUENT Inc
FLUID-STRUCTURE-MESH COUPLINGFLUID-STRUCTURE-MESH COUPLING
CFD – Computational Fluid DynamicsCFD – Computational Fluid Dynamics CSD – Computational Structural DynamicsCSD – Computational Structural Dynamics CMD – Computational Mesh DynamicsCMD – Computational Mesh Dynamics
FSI
CFD CSD CMD
General classificationGeneral classification Transient FSITransient FSI: : The structure’s reaction forces continuously vary with The structure’s reaction forces continuously vary with
timetime Steady-state FSISteady-state FSI: : The loads induced by the fluid are exactly balanced The loads induced by the fluid are exactly balanced
by the structure’s reaction forces and the structure reaches a displaced by the structure’s reaction forces and the structure reaches a displaced equilibrium positionequilibrium position
FSI-coupling schemesFSI-coupling schemes
StrongStrong: : Fluid and structure are modeled as a continuum Fluid and structure are modeled as a continuum with a single system of partial differential equationswith a single system of partial differential equations
LooseLoose: Separate solvers for both fluid and structure: Separate solvers for both fluid and structure
Grid Generator
Fluid solver
Structure
{ } { }
{ }
U U
Ui t i t
i t
1
t=t+∆t
t ≤ tfsi
T≤t+i
BEGIN
END
Initial Data
Sub-iteration loop
NO
YES
YES
NOFluid, Structure solvers restart
FSI iteration loop
Pressure transfer
Displacement & Velocity of Center and FSI interface
Reads velocities from structure solver in each sub-iteration
Reads displacements
LOOSE-FSI ALGORITHM
Blue region – Key to implicit method
FSI-Time stepping methodsFSI-Time stepping methods
ImplicitImplicit – – Coupling with sub-iterationsCoupling with sub-iterations
Explicit Explicit – – Coupling without sub-iterationsCoupling without sub-iterations
FSI in this projectFSI in this project
TIME DEPENDENT + LOOSE + EXPLICITTIME DEPENDENT + LOOSE + EXPLICIT
RWIV-Need for RWIV-Need for loose couplingloose coupling
Nonlinear structural solver and a nonlinear fluid solver are Nonlinear structural solver and a nonlinear fluid solver are minimum requirements for the problem under considerationminimum requirements for the problem under consideration
It would be computationally inefficient to develop a new It would be computationally inefficient to develop a new Aeroelastic / FSI tool to study this problemAeroelastic / FSI tool to study this problem
Best alternative would be to exploit the utility of well proven Best alternative would be to exploit the utility of well proven CFD and CSD codes and combine themCFD and CSD codes and combine them
ANSYS+CFX & ABAQUS+FIDAPANSYS+CFX & ABAQUS+FIDAP
Computational Data TransferComputational Data Transfer
Structural Code
Fluids Grid Deformation
Structures andFluids Interface
Fluid SolverPressures
Deflections
Structural Grid deflections
New Fluid Grid
STIMULUS-IISTIMULUS-II Python is simple enough to stay out of the way of Python is simple enough to stay out of the way of
the creative process -- like the pencil used by a the creative process -- like the pencil used by a sketch artist -- yet powerful enough to create sketch artist -- yet powerful enough to create sophisticated systems -- like an expensive CAD sophisticated systems -- like an expensive CAD program program
- - Guido van RossumGuido van Rossum
Why Python ?Why Python ? A clean syntaxA clean syntax
Ex: print ‘RWIV’ not print *, ‘RWIV’ as in FortranEx: print ‘RWIV’ not print *, ‘RWIV’ as in Fortran
not cout << “RWIV” << ; as in C++not cout << “RWIV” << ; as in C++
A flexible interface to compiled languagesA flexible interface to compiled languages Automatic interface generators for C/C++ and FortranAutomatic interface generators for C/C++ and Fortran Large library of reusable code, both general and scientificLarge library of reusable code, both general and scientific Robust guidance and support from python users throughout Robust guidance and support from python users throughout
the world the world
Versatility of “Python”Versatility of “Python” PyMat – Matlab PyMat – Matlab PyMPI - MPIPyMPI - MPI PyCGNS – A python binding to CGNSPyCGNS – A python binding to CGNS PyVTK – Visualization tool kitPyVTK – Visualization tool kit SciPy – Scientific computing tool kitSciPy – Scientific computing tool kit NumPy- Numeric pythonNumPy- Numeric python PIL – Imaging libraryPIL – Imaging library Python and TCL/TKPython and TCL/TK PySQLPySQL SWIGSWIG F2PYF2PY PyxmgracePyxmgrace SIP for C++ bindings, similar to SWIGSIP for C++ bindings, similar to SWIG PyFort similar to F2PYPyFort similar to F2PY Visual PythonVisual Python
Different codes considered for this projectDifferent codes considered for this project
• Ogen Ogen – overlapping grid generator– overlapping grid generator from LLNL, Californiafrom LLNL, California
Compatible with OVERFLOW Compatible with OVERFLOW
• ANSYSANSYS – Nonlinear Structural solver – Nonlinear Structural solver
• GHOSTGHOST – Solves 2D incompressible Navier stokes equations – Solves 2D incompressible Navier stokes equations
incompressible, fully structured multiblock Navier-Stokes solver incompressible, fully structured multiblock Navier-Stokes solver 22ndnd order in space and 2 order in space and 2ndnd order in time order in time Supports MPI Supports MPI ALE enabled ALE enabled
• LESToolLESTool - - Solves 3D compressible Navier stokes equations Solves 3D compressible Navier stokes equations Used on numerous platforms (IBM SP2, SGI Origin 2000, PC Cluster KFC1) 5th order accuracy in space, 2nd order accuracy in time Implicit time discretization (Modified ADI) Distributed parallelism using MPI and OpenMP Turbulence models: RANS, DES, LES, DNS CGNS based input/output
Software codes - characteristicsSoftware codes - characteristics
OgenOgen – – written in C++ - written in C++ - Source accessibleSource accessible
LESToolLESTool – – Fortran 90 - Fortran 90 - Source accessibleSource accessible
GHOST GHOST – – Fortran 90 - Fortran 90 - Source accessibleSource accessible
ANSYSANSYS – – based on fortran 77 libraries – based on fortran 77 libraries – No source access No source access
Linking with PythonLinking with Python
F2PYPython LESToolLESTool
F2PYPython GHOSTGHOST
SWIGPython OgenOgen
PythonFortranANSYSF2PYLibrary linking
SWIG – Simplified Wrapper and SWIG – Simplified Wrapper and Interface GeneratorInterface Generator
SWIG is a software development tool that connects programs SWIG is a software development tool that connects programs written in C and C++, primarily used with common scriptingwritten in C and C++, primarily used with common scripting
languages such as Pythonlanguages such as Python
class Overture { public: static int start(int argc, char *argv[]); static int finish();};
Input file for SWIG
%module overturec%{
#include </home/satish/OVERTURE/Overture.v19/include/OvertureInit.h> %}
swig -c++ -python <input file> >>import overturec >>map1=overturec.Overture >>map1.start() >>map1.finish()
F2PY – Fortran to Python Interface F2PY – Fortran to Python Interface GeneratorGenerator
Provides a connection between Fortran and Python Provides a connection between Fortran and Python languagueslanguagues
To call Fortran 77/90/95 external subroutines and Fortran To call Fortran 77/90/95 external subroutines and Fortran 90/95 module subroutines as well as C functions 90/95 module subroutines as well as C functions
To access Fortran 77 COMMON blocks and Fortran 90/95 To access Fortran 77 COMMON blocks and Fortran 90/95 module data, including allocatable arrays module data, including allocatable arrays
subroutine ansys_input(xcenter,ycenter)real::xcenter,ycenter,rad,depthopen(1,file=‘cylinder.dat')write(1,*)'/PREP7'write(1,*)'CYL4' , ',' ,xcenter, ',' ,ycenter write(1,*)'et', ',' , '1' , ',' , 'shell63‘End subroutine ansys_input
Just do this : f2py –c –m ansysinput ansys_input.f90
>>import ansysinput>>ansysinput.ansys_input(5,6)
ANSYS as a SubroutineANSYS as a Subroutine ANSYS can become one of the subroutines of your fortran programANSYS can become one of the subroutines of your fortran program A “Makefile” to link ANSYS libraries was writtenA “Makefile” to link ANSYS libraries was written Programmatically more efficientProgrammatically more efficient mainan() is the keymainan() is the key !! !!
open (177,file=‘ANSYS input file') do read(177,'(A)',iostat=ioerror)cmd if(ioerror /=0)exit ncommand = len_trim(cmd) where = mainan(ncommand,cmd) enddo close(177)
PythonFortranANSYSF2PYLibrary linking
1( ) ( )
Rei i i
j gridj i j i
u u upu u
t x x x x
1( ) ( )
Rei i
i jj i j i
u upu u
t x x x x
ALE – Arbitrary Lagrangian Eulerian formulation
Ugrid is the velocity of grid
Incompressible NS equations
Python-FSI ModulesPython-FSI Modules
Python – GHOST – ANSYS Python – GHOST – ANSYS Python – Ogen – LESTool - ANSYSPython – Ogen – LESTool - ANSYS
Python-enabled simulationPython-enabled simulation
GHOST
Input Files
Input Files
Grid.dat
Grid
Python Displacements and Velocities
ANSYS
F2PY
Input Files,Forces
Pressures
Python-Driver ScriptPython-Driver Scriptdef fsi_iterate():def fsi_iterate():
grid_generator()grid_generator()
fluid_solver()fluid_solver()
pressure_to_force()pressure_to_force()
structure()structure()
def grid_generator():def grid_generator():
import overturec #imports module created by SWIGimport overturec #imports module created by SWIG
# Creates grid with user parameters# Creates grid with user parameters
def fluid_solver():def fluid_solver():
def structure():def structure(): #imports F2PY module for interface with ANSYS #imports F2PY module for interface with ANSYS
# uses ANSYS as a subroutine# uses ANSYS as a subroutine
fsi_iterate()fsi_iterate()
GHOST
Input Files
Input Files
Grid.dat
Grid
Python Displacements and Velocities
ANSYS
F2PY
Input Files,
ForcesPressures
SETUP FOR FSI Simulations
VORTEX-INDUCED VIBRATIONS - FSIVORTEX-INDUCED VIBRATIONS - FSI
Boundary layers separate and two shear layers that aft trail in the flow are formed
Fluid flow around a bluff object at subsonic flows
Vortex Shedding at Re= 3000
SCHEMATIC OF FLUID GRID
Inflow velocity = 1
Diameter of cylinder (D) = 1
Length = 80D, Width = 40D, Overset grid = 8D
98000 GRID POINTS (Background + Overset)
**GHOST input parameters are non-dimensional**
Structural Model in ANSYS
•2D cylinder with 2 springs and 2 dampers
•Rotational DOF constrained
Diameter of cylinder: 100 mm
Mass of the structure: 6157.31 gm
Actual flow velocity: 30 mm/sec
Damping constant for x-damper: 3.614 g/s
Damping constant for y-damper: 0.337 g/s
Damping factor = 0.00032
Handling unitsHandling units
Actual flow velocity = 30 mm/secActual flow velocity = 30 mm/sec Actual Diameter = 100 mmActual Diameter = 100 mm TIME SCALETIME SCALE = 100/30 = 3.33 sec = 100/30 = 3.33 sec
ANSYS TIMESTEP = 3.33 * GHOSTANSYS TIMESTEP = 3.33 * GHOST
Validation of CFD code GHOSTValidation of CFD code GHOST
2 test cases based on the two-dimensional viscous laminar flow over a 2 test cases based on the two-dimensional viscous laminar flow over a 2-D circular cylinder 2-D circular cylinder
CFD Test Case 1: Vortex Shedding at Re=300CFD Test Case 1: Vortex Shedding at Re=300Diameter of cylinder in fluid: 1Diameter of cylinder in fluid: 1Fluid Flow Velocity: 1Fluid Flow Velocity: 1Fluid Density: 1Fluid Density: 1Fluid Viscosity: 0.00333Fluid Viscosity: 0.00333Timestep: 0.005Timestep: 0.005
CFD Test Case 2CFD Test Case 2: : Vortex Shedding at Re = 1000Vortex Shedding at Re = 1000Diameter of cylinder in fluid: 1Diameter of cylinder in fluid: 1Fluid Flow Velocity: 1Fluid Flow Velocity: 1Fluid Density: 1Fluid Density: 1Fluid Viscosity: 0.001Fluid Viscosity: 0.001Timestep: 0.005Timestep: 0.005
Lift and Drag at Re=300 Lift and Drag at Re=1000
Vortex shedding over a circular cylinder in cross flow
Reynolds Number 300 1000
Present results CL= 0.771
CD= 1.3530.077
St= 0.207
CL=1.263
CD=1.4530.212
St=0.230
Chen et al [103] CL=0.869
CD=1.3540.072
St=0.21
CL=1.378
CD=1.4890.198
St=0.239
Ronald et al. [106] CL=0.841
CD=1.34
St=0.2036
Qian and Vezza [105] CD=1.52
St=0.24
Summary of previous and present computational
results for CFD test cases
FSI TEST CASE FSI TIME STEP FSI TECHNIQUE SPRING STIFFNESSX,Y directions
1(a) 0.016666 First order explicit (Classical Staggered Scheme)
X- 5032.392 g/s2
Y- 1258.8 g/s2
1(b) 0.006666 First order explicit(Classical Staggered Scheme)
X- 5032.392 g/s2
Y- 1258.8 g/s2
1(c) 0.016666(High spring stiffness case)
First order explicit(Classical Staggered Scheme)
X- 4.092e7 g/s2
Y- 4.751e7 g/s2
1(d) 0.016666 Adam-Bashforth third order method
X- 5032.392 g/s2
Y- 1258.8 g/s2
1(e) 0.16666 First order explicit(Classical Staggered Scheme)
X- 5032.392 g/s2
Y- 1258.8 g/s2
FSI Test cases (based on Fan et al)
TIMESTEPPING METHOD FOR FSI Test cases 1(a,b,c,e)
Farhat et al
Initial Conditions for FSI test casesInitial Conditions for FSI test cases
Oscillatory vortex street in the Oscillatory vortex street in the case of flow over a 2D cylinder case of flow over a 2D cylinder at Re=3000at Re=3000
Lift frequency= 0.239 HzLift frequency= 0.239 Hz Drag frequency=0.496 Hz Drag frequency=0.496 Hz Cylinder freq (y)= 0.072 HzCylinder freq (y)= 0.072 Hz Cylinder freq (x)=0.143 HzCylinder freq (x)=0.143 Hz
VORTICITY
Results for Re=3000 initial conditions caseResults for Re=3000 initial conditions case
Lift coefficient from figure 6.3 = Lift coefficient from figure 6.3 = 1.5061.506 Drag coefficient from 6.3 = 1.566Drag coefficient from 6.3 = 1.5660.2540.254 Strouhal number = 0.239 ( based on lift frequency ) – (f*D)/UStrouhal number = 0.239 ( based on lift frequency ) – (f*D)/U Reduced Velocity = Inverse of Strouhal number = 4.184Reduced Velocity = Inverse of Strouhal number = 4.184
2.7 < Ur < 4.5: Expected path of the cylinder motion is a Lissajou figure
Ur > 4.5 – The cylinder motion is predominantly in the lift direction
1.25 < Ur < 2.7 – The cylinder performs steady oscillations in the drag direction with a small amplitude in the lift direction
PRESSURE(P) AND VORTICITY(V) CONTOUR SNAPSHOTSFluid time: 67.7 sec (P) Fluid time: 75.4 sec (P)
Fluid time: 72.7 sec (P) Fluid time: 75.4 sec (V)
Snap shot of pressure contour at 75.4 secondsSnap shot of pressure contour at 75.4 seconds
-ve max lift coefficient at 75.4 secondsHigher pressure at the bottom
Lower pressure at the top
FSI test case 1(a) resultsFSI test case 1(a) results
Time step: 0.01666Time step: 0.01666 Technique: First order explicit-CSSTechnique: First order explicit-CSS X spring- 5032.392 g/sX spring- 5032.392 g/s22
Y spring- 1258.800 g/sY spring- 1258.800 g/s22
Fluid time: 82.77 sec
CL and CD variation
Vorticity
Pressure
X-Displacement history Y-Displacement history
Displacement and velocity histories – Case 1(a)
X-Velocity history Y-Velocity history
Drag, X-displacement and velocityDrag, X-displacement and velocity Lift, Y-displacement and velocityLift, Y-displacement and velocity
Plots of comparison without including the region of instability
(Also showing the inherent phase difference between the quantities)
**Velocity scaled up by 50 times for clarity**
PRESSURE CONTOUR at FLUID TIME 80.4 seconds SNAPSHOT
Higher pressure at the bottom
Lower pressure at the top
CL peak at 80.4 seconds
FSI along with FLUID – CL & CD variation
VORTICITY CONTOURS – FSI case 1(a)
FSI test case 1(b) - resultsFSI test case 1(b) - results
Time step: 0.00666Time step: 0.00666 Technique: First order explicit-CSSTechnique: First order explicit-CSS X spring- 5032.392 g/sX spring- 5032.392 g/s22
Y spring- 1258.800 g/sY spring- 1258.800 g/s22
Changed from 1(a)
CL & CD
Displacements history (0-10: x-axis scale)
X-displacement
Y-displacement
Cylinder velocity history plots
x-velocity y-velocity
CL – case 1(a) & 1(b) CD – case 1(a) & 1(b)
Cases 1(a) and 1(b) agree until FSI time 8 seconds
Y-displacementX-displacement
FSI test case 1(c) - resultsFSI test case 1(c) - results
Timestep: 0.01666Timestep: 0.01666Technique: First order explicit-CSSTechnique: First order explicit-CSSX spring- X spring- 4.092e7 g/s2 g/s2Y spring- Y spring- 4.751e7 g/s2g/s2
Higher stiffness for springs
Changed from 1(a)
Displacement & Velocity history plots for case 1(c)
Unstable region similar to that of case 1(a)
FSI test case 1(d)FSI test case 1(d)
ADAMS-BASHFORTH METHOD – Implemented in PythonADAMS-BASHFORTH METHOD – Implemented in Python
First stepFirst step: y: ykk + h*f + h*fkk
Second stepSecond step: Second order Adams-Bashforth method: y: Second order Adams-Bashforth method: yk+1k+1= y = y kk+ (h/2)*(3f+ (h/2)*(3fkk – –
ffk-1k-1) )
Third step and beyondThird step and beyond: y: yk+1k+1= y= ykk + (h/12)*(23f + (h/12)*(23fkk - 16f - 16fk-1k-1+ 5f+ 5fk-2k-2) )
‘‘k’ is the time level and the product hfk’ is the time level and the product hfkk denotes the change in the value at that time level denotes the change in the value at that time level
FSI test case 1(d) – resultsFSI test case 1(d) – results (ADAMS-BASHFORTH THIRD ORDER METHOD)(ADAMS-BASHFORTH THIRD ORDER METHOD)
CL CDThese plots compare 1(a) and 1(d) cases
Unstable region at 80 seconds
FSI test case 1(e) – resultsFSI test case 1(e) – results
CL & CDNever went unstable
Technique: Technique: First order explicit-CSSFirst order explicit-CSS
X spring- 5032.392 g/s2X spring- 5032.392 g/s2Y spring- 1258.800 g/s2Y spring- 1258.800 g/s2
ANSYS Time step: 0.1666ANSYS Time step: 0.1666
GHOST Time step: 0.05GHOST Time step: 0.05
Changed from 1(a)
Displacements history
Velocities history
FSI CASE 1(e) – VORTICITY CONTOURS
Zoomed view of cylinder
FSI TEST CASE
FSI TIME STEP
FSI TECHNIQUE
SPRING STIFFNESSX,Y directions
RESULT
1(a) 0.016666 First order explicit (Classical Staggered Scheme)
X- 5032.392 g/s2Y- 1258.8 g/s2
UNSTABLE atFSI 18 sec
1(b) 0.006666 First order explicit(Classical Staggered Scheme)
X- 5032.392 g/s2Y- 1258.8 g/s2
UNSTABLE atFSI 18 sec
1(c) 0.016666(High spring stiffness case)
First order explicit(Classical Staggered Scheme)
X- 4.092e7 g/s2Y- 4.751e7 g/s2
SLIGHT INSTABILITY at FSI 18 sec
1(d) 0.016666 Adam-Bashforth third order method
X- 5032.392 g/s2Y- 1258.8 g/s2
UNSTABLE atFSI 18 sec
1(e) 0.16666 First order explicit(Classical Staggered Scheme)
X- 5032.392 g/s2Y- 1258.8 g/s2
COMPLETELY STABLE
SUMMARY OF RESULTS
ConclusionsConclusions
The results of current FSI simulations appear qualitatively The results of current FSI simulations appear qualitatively correctcorrect
Response of the cylinder is very sensitive to time steppingResponse of the cylinder is very sensitive to time stepping Higher time step may be a solution to certain FSI casesHigher time step may be a solution to certain FSI cases Python and Python based programming tools are efficient Python and Python based programming tools are efficient
means of automating loose coupling algorithms for means of automating loose coupling algorithms for FSI/AeroelasticityFSI/Aeroelasticity
Future WorkFuture Work The results of simulations in this project may be checked with other The results of simulations in this project may be checked with other
benchmarks for quantitative accuratebenchmarks for quantitative accurate Future implementation of MPI using PyMPI for parallel computation on Future implementation of MPI using PyMPI for parallel computation on
commodity clusters commodity clusters Optimize Python code with Numerical Python arraysOptimize Python code with Numerical Python arrays Implement interpolation algorithms in Python for flexible body FSIImplement interpolation algorithms in Python for flexible body FSI Future comparison of results with those of ANSYS-CFX, ADINA-FSI, Future comparison of results with those of ANSYS-CFX, ADINA-FSI,
NISA-FSI, LINFLOW and such other readily available fluid-structure NISA-FSI, LINFLOW and such other readily available fluid-structure interaction software's for more complex FSI benchmarksinteraction software's for more complex FSI benchmarks
AcknowledgementsAcknowledgements
Dr.Raymond LeBeauDr.Raymond LeBeau Dr.Suzanne Weaver SmithDr.Suzanne Weaver Smith Dr.Thomas HauserDr.Thomas Hauser Dr.Jamey JacobDr.Jamey Jacob Dr.Peter Attar, Airforce Research Labs,DaytonDr.Peter Attar, Airforce Research Labs,Dayton Mr.Satish Vanimisetti, ECSMr.Satish Vanimisetti, ECS Dr.Bora Suzen, CFD GroupDr.Bora Suzen, CFD Group Friends Friends