vista: a multi -field object oriented cfd -package · 3. nafems cfd-seminar wiesbaden, 08.-09. mai...
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3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Vista: A MultiVista: A Multi --field Object Oriented field Object Oriented CFDCFD--packagepackage
T. Kvamsdal1, R. Holdahl1 and P. Böhm2
1SINTEF ICT, Applied Mathematics, Norway2inuTech GmbH, Germany
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Outline
• inuTech & SINTEF
• VISTA – a CFD Solver
• VISTA – a CFD Toolbox
• Extrusion example: Extrud3D
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
inuTech - Our Object
Closing the Gap between
Engineering and Mathematics
to Solve Engineering and
Mathematical Problems
R&D of Numerical Methods Sales and Support of
Software
R&D of Numerical Methods Sales and Support of
Software
Seminars and Training Seminars and Training
Consulting Consulting
inuTech - Our Objectives
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Univ. of Oslo
Univ. of Erlangen
Univ. of Bayreuth
The Team
(resellers world-wide)
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
VISTAA CFD-Solver
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Vista Extrud Vista Marine
VISTA: A Multi-field Object Oriented CFD-package
Incompressible Navier-Stokes equation:
+ H
eat-
Pro
blem
+ A
LE
+ F
ree-
surf
ace
flow
+ T
urbu
lenc
e+
Flu
id-s
truc
ture
In
tera
ctio
n
Bloodflow-Problem1
(based on VISTA)
1 phd-thesis Runar Holdahl
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Large-eddy simulation of flow around two cylinders in atandem arrangement, Re=22000,
velocity isosurface and pressure distribution
Viscous 3D flow around a cylinder, Re=265,velocity isosurface
VISTA MarineVISTA Marine
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
• Block structured, 8 node hexahedral FE-elements
• LES-turbulence model (Smagorinsky, Van Driest)
• Number of time steps: 5000
• Number of grid points: 770 982
• Total no. of degrees of freedom: 3 083 928
• Number of processors: 96
Parallel computers necessary for addressing this ca se!
Computational Facts
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Feature List
• Incompressible flow
– Stokes/Navier-Stokes
– 2D/3D
– stationary and time dependent
– variable density
• Turbulence modeling
– LES (Smagorinsky with van Driest damping)
– RANS (k-e: High Reynolds model)
• Reference system and boundary conditions
– ALE formulation
– Moving object (FSI)
– Free surface
– Periodic boundary conditions
– General boundary conditions(Dirichlet/Neumann)
• Numerical approximation
– (Mixed) finite elements(Taylor-Hood, equal order)
– Continuous projection method(including incremental pressure formulation)
– Semi-implicit BDF time discretisation
– Parallel Krylov solver reconditionedwith two-level domain decomposition
• Software issues
– Object-oriented (c++) code based on Diffpack
– Platform independent (running on Unix/Linux)
– Parallelised with MPI
– Preprocessor: GRIDDLER
– Postprocessor: GLview, VTK, Matlab (2D)
• Usage
– NTNU/SINTEF: Free usage for education and research
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
VISTAA CFD-Toolbox
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
VISTA “Plug and Play”
(+ Diffpack)
VISTA “Plug and Play”
(+ Diffpack)
The VISTA Vision
Heat-Problem
Navier-Stokes related problem
Navier-Stokes related problem + =
owncoupled
CFDsolver
owncoupled
CFDsolver
Turbulence
Free-Surface
Fluid-Surface-Interaction
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Diffpack Kernel
Diffpack Toolboxes(further extensions)
Diffpack Kernel
Diffpack Toolboxes(further extensions)
The Diffpack® Vision
[ ] in
on
u f
u g
κ−∇ ⋅ ∇ = Ω= ∂Ω
“arbitrary” PDE, ODE,
or othernumerical problem
“arbitrary” PDE, ODE,
or othernumerical problem
+ = ownsolver
ownsolver
( ), ,v tt
∂ =∂s
F s
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Philosophy: Plug and play
CoupledSolver
SimCase
Problem1 Problem2
Solver1 Solver3Solver2
Data transfer by:• “get”-functions• “attach”-functions
Divide et Impera!
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Example 1: Free-surface flow
FreeSurfaceSolverSimCase
InterfaceProblem ALEproblem
InterfaceSolver MeshMoverFluidSolver
FluidProblem
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Vista Software - Current and Future Modules
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
FSIsolver
FluidSolver StructureSolver MeshMover
Example 2: FluidExample 2: Fluid--structure interactionstructure interaction
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
VISTAExtrud3D
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extruded Products
Building industries Automotive industry
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
The Extrusion Press
Profile
Die holder
Die
Container
Billet
Ram
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
T3
T2
P1
T1
15
3
5
6
4
1
Die
ProfileSlip
Sharp inlet
Flat Strip: Measurement points
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Mathematical Formulation
• The Extrusion Problem
• Governing Equations
• Boundary Value Problems
• The Extrusion Solver
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - The Domain
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Governing Equations
Heat conduction:
non-Newtonian fluid:Zener-Hollomon material model
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - Boundary Value Problem
Coupling throughtemperature dependentviscosity
Coupling throughadvection
Coupling throughdeformationenergy
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - Boundary Value Problem (cont’d)
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - Weak Formulation
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - Weak Formulation (cont’d)
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - Linearized Fluid Flow Equations
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - Linearized Fluid Flow Equations (cont’d)
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - Computer Implementation
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - Model Parameter
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Flat Strip: 2D-mesh
Profile
Die
Container
RamNumber of elements = 504
Billet (Aluminium)
Detail
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Flat Strip: 3D-mesh
Grids do not necessarily match
Solve for• velocity u• pressure p • temperature T
Solve for temperature T
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Friction
Full stick
Full slip
Visco-plastic
Slip point
Bearing Channel
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Comparison with Experiments
• Extrusion of a Flat Strip
• Temperature measurements
– Aluminum
– Die
• Both 2D and 3D analyses
78.5
15
6 6
9 4 1.7
T2
3
B B
A
A
T3
T4
T1
P1
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Finite Element Model
Full 3D-model Close up
Mesh
Temperature
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Extrusion Problem - The Solver
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Flat Strip: Temperature
t = 4.4 s t = 16.7 s
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Flat Strip: Velocity
t = 11.9 s t = 16.7 s
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
TEMPERATURE IN T1 (°C)
460
480
500
520
540
560
580
600
620
0 20 40 60 80 100 120
rampos(mm)
T1_v09_480_stick
T1alu_v09_480_exp
y
z
T1 T4
x
Flat Strip: Temperatures in T1
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
TEMPERATURE IN T2 (°C)
420
430
440
450
460
470
480
490
500
0 20 40 60 80 100 120
rampos(mm)
T2_v09_480_stick
T2die_v09_480_exp
T2dT3d
x
y
z
Flat Strip: Temperatures in T2
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Thank you for attention !Thank you for attention !
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Feature List
• Incompressible flow
– Stokes/Navier-Stokes
– 2D/3D
– stationary and time dependent
– variable density
• Turbulence modeling
– LES (Smagorinsky with van Driest damping)
– RANS (k-e: High Reynolds model)
• Reference system and boundary conditions
– ALE formulation
– Moving object (FSI)
– Free surface
– Periodic boundary conditions
– General boundary conditions(Dirichlet/Neumann)
• Numerical approximation
– (Mixed) finite elements(Taylor-Hood, equal order)
– Continuos projection method(including incremental pressure formulation)
– Semi-implicit BDF time discretisation
– Parallel Krylov solver reconditionedwith two-level domain ecomposition
• Software issues
– Object-oriented (c++) code based on Diffpack
– Platform independent (running on Unix/Linux)
– Parallelised with MPI
– Preprocessor: GRIDDLER
– Postprocessor: GLview, VTK, Matlab (2D)
• Usage
– NTNU/SINTEF: Free usage for education and research
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Structural Optimization Topology Optimization Shape Optimization Sizing- and Parameter Optimization Large Scale Optimization Multi-Disciplinary Optimization Design of Experiments Biological Growth Free Material Optimization
(Composite Design)
Structural Optimization Topology Optimization Shape Optimization Sizing- and Parameter Optimization Large Scale Optimization Multi-Disciplinary Optimization Design of Experiments Biological Growth Free Material Optimization
(Composite Design)
inuTech - Our R&D Experience
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Differential Equations inuTech develops and markets the Diffpack Product
Line for the Numerical Modeling and Solution of Differential Equations
inuTech offers Consulting Services around Diffpack; we can deliver customized turn-key solutions for specialized simulation problems
Attention: Diffpack is a development environment, not a program!It allows you to generate asimulator!
Differential Equations inuTech develops and markets the Diffpack Product
Line for the Numerical Modeling and Solution of Differential Equations
inuTech offers Consulting Services around Diffpack; we can deliver customized turn-key solutions for specialized simulation problems
Attention: Diffpack is a development environment, not a program!It allows you to generate asimulator!
inuTech - Our R&D Experience
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
The Diffpack® Distribution
Diffpack Development Framework
Diffpack Kernel(computing/numerics)
Diffpack Toolboxes
Third-Party Pre-/Postprocessors
OpenSource Pre-/PostprocessorsDif
fpa
ckU
tilit
y
Pro
gra
ms
Books, Manpages,
Reports
Supportphone/e-mail
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
The Challenge
Software DevelopmentSoftware Development
Num
eric
al M
etho
dsScientific Computing
Speed-Up 1,000,000 over last 50 years
Speed-Up 1,000,000 over last 50 years
Hardw
are Power
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
The Diffpack® Vision (cont’d)
Structuralmechanics
Porous mediaflow
Aero-dynamics
Incompressibleflow
Other PDEapplications
Waterwaves
Electromagnetics
Heattransfer
Field
Grid
MatrixVector
I/O
Ax=b
FEM
FDM
Observation:Methodology basisindependent of applications
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Diffpack® Implementation - use weak formulation
[ ] in
on
u f
u g
κ−∇ ⋅ ∇ = Ω= ∂Ω
solve on operator level ×1
, 1,..., in
on
m
j i j ij
N N d u f N d i m
u g
κ= Ω Ω
∇ ∇ Ω + = Ω = Ω
= ∂Ω
∑ ∫ ∫
Use weak formulation
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Diffpack® Implementation - important member
global_menu.multipleLoop (S)
S::adm
S::define
S::scan
S::solveProblem
S::integrands
FEM::makeSystem
FEM::calcElmMatVec
FEM::numItgOverElm
S::resultReport
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
bAu
midNfudNNvdNNk i
m
jjijij
=
=Ω=
Ω∇⋅+Ω∇∇ ∫∑ ∫∫
Ω= ΩΩ
,...,1 , 1
Weak Formulation ( ):0=α
ConvDiff:: integrands (numerical kernel)
3. NAFEMS CFD-Seminar Wiesbaden, 08.-09. Mai 2006
Apply Boundary Conditions:
1, ,0),( Γ∈= yxyxu “essential conditions”
ConvDiff :: fillEssBC (apply essential boundary Conditions)