Prof. Patrick Jenny (ETH - Zurich, Switzerland), FROM HIGH PRESSURE TO VACUUM - FOKKER-PLANCK/DSMC METHOD FOR GAS DYNAMICS AT ALL KNUDSEN NUMBERS
Classical CFD is well established to simulate ow in the continuum limit, and for high Knudsen number (Kn) gas ow Direct Simulation Monte Carlo (DSMC) is very efficient and accurate. More challenging are problems subjected to Kn ranging from small to large.

ABSTRACT

Classical CFD is well established to simulate ow in the continuum limit, and for high Knudsen number (Kn) gas ow Direct Simulation Monte Carlo (DSMC) is very efficient and accurate. More challenging are problems subjected to Kn ranging from small to large. A good example is satellite attitude control, where continuum conditions are met inside the thrusters and near vacuum outside. To cope with such scenarios, a Fokker-Planck/DSMC method was devised. The basic idea consists in replacing the collision operator in DSMC by a Fokker-Planck model,
wherever the local Kn is small.


ABOUT THE SPEAKER

In May 2003 Patrick Jenny joined the Institute of Fluid Dynamics at the ETH Zurich as a SNF-Professor of Computational Fluid Dynamics. In August 2006 he was promoted to Associate Professor and since 2012 he is a Full Professor. In 1997 he received his PhD in Computational Fluid Dynamics (CFD) under the supervision of Professor Bernhard Müller at the ETH Zurich. His research was mainly about developing numerical algorithms to solve the compressible Navier-Stokes equations for reactive ow with applications to studies of thermoacoustic instabilities. From July 1997 till October 1999 he was a member of Professor Stephen B. Pope's Turbulence and Combustion Group in the Mechanical and Aerospace Engineering Department of Cornell University in the Unites States. His research dealt with probability density function (PDF) modeling of turbulent reactive ow. The time was primarily spent to develop a new hybrid Monte Carlo/ nite-volume algorithm for solving the fully joint velocity-frequency-composition PDF transport equation for turbulent reactive ow. From November 1999 till April 2003 he was in the reservoir simulation and optimization research group of ChevronTexaco in San Ramon, California. He worked on the company's next-generation oil reservoir simulator project and his main responsibilities included discretization issues, multi-scale modelling and PDF modelling for uncertainty assessment in oil reservoir simulation. His current research focuses on modelling of turbulent flows, subsurface flows, biomedical flows and rare ed gas dynamics. Patrick Jenny received the National Latsis Prize 2005.