Tools for Multi-Physics Simulation

Hans Petter Langtangen

Simula Research Laboratory

Oslo, Norway

Department of Informatics,

University of Oslo

Present Simula projects

History of the group

Python

PythonC++

multi-physics

PDE components

F77

Future ideas/visions

Waterwaves

Heattransfer

StochasticPDEs

Other PDEapplications

Porous mediaflow

Aero-dynamics

Incompressibleflow

1990s: Diffpack & applications

Structuralmechanics

Field

Grid

MatrixVector

I/O

Ax=b

FEM

FDM

Class P1

Grid* grid;Field* p;LinEqAdm* Axb;

integrands (…);K(…);

A Typical Diffpack PDE Solver

Finite element grid

Finite element field

CbCAx

bAx

BiCGStab

CG MG

Linear equations and solvers

Evaluate integrands in weak formEvaluate variable coefficient

Diffpack distribution

• 1995 & 1997: Open source versions• 1997-2003: Numerical Objects• 2003-?: inuTech• Free test version (size limit)• Simula collaborators have free access• Customers include Cornell, Stanford,

LLNL, Intel, NASA, Shell, IFP, DaimlerCrysler, Mitsubishi, ...

• >200 customers in >30 countries

Some Diffpack features

• Linear solvers and preconditioners• Grids and scalar/vector fields• Biased towards FEM, support for FDM• Mixed FEM, block systems• Systems of PDEs• Stochastic PDEs• Multilevel solution• Adaptive mesh (h-adaptivity)• Parallel computing• Problem solving environment

Some Diffpack applications

• Heat and phase transfer• Viscous laminar and turbulent flow• Thermo-elastic-plastic deformation• Electromagnetics• Chemical reactors• Design of quantum computers• Stochastic porous media flow• Electrical activity in the heart• Tsunami simulation• ...

Simula is a new government lab for advanced ICT research

StartupJan 1, 2001

High quality research

Educate graduate university students

Prepare for research-

based business

Research groups were selected by competition

11 Applicants

Scientific Computing

Software Engineering

Networks and Distributed Systems

Simula emphasizes large projects

Software

for PDEs

Cardiac

Computing

Inverse

problemsComputational

geosciences

Computing the electrical activity in the heart

This is a computationally intensive problem

39 million unknowns

231 million elements

400-500 millions

of ODEs

42 million unknowns

252 million elements

Computational geosciences

• Goal: find more oil!• Compute geological evolution• Multi-resolution visualization• PDEs for deposition/erosion• Flow, heat, deformation• Software integration• Advanced tools for tracking

geological events

t

t

Offshore Geohazards –Tsunami generation

The Storegga Slide (8150 yrsBP)

Headwall 300 kmRun-out 800 kmVolume 5.600 km3

Area 34.000 km2

The Mjølnir asteroide impact

Barents Sea, 142 mill. years ago

The Mjølnir event was 1000 times stronger than the Dec 26, 2004 event!

The Mjølnir tsunami consisted of a series of individual waves

The evolution of the front of the tsunami

The Silent Wings soaring simulator uses advanced terrain visualization

FAMMS

Python

SWIG/F2PY

GiNaC C++/F77

SWIG