IGM Colloquium: Direct Numerical Simulation of Drop Dynamics
23.11.17 - The numerical prediction of two-phase flows is generally difficult
Normally a lot of simplifications and assumptions have to be made. On the other hand, a lot of two-phase flow phenomena are present in our daily life and in a lot of technical processes. In many of these processes single droplets or interactions of droplets are of great interest (e.g. injection, interaction and evaporation of fuel droplets in a rocket or car engine or a gas turbine combustion chamber, clouds formation, rain droplets, air pollution, sprays in medical applications,…). The ITLR in Stuttgart has developed over the past 20 years a CFD code named FS3D (Free Surface 3D), which is able to predict droplet interactions, droplet evaporation as well as jet instabilities by using direct numerical simulation (DNS). The computational resources needed for this approach are high, so that the code is run normally on the supercomputers in Stuttgart. Grid sizes of about several billion cells have been used already successfully.
In this lecture several different applications of FS3D will be shown after a short explanation of the basics of a direct numerical simulation. The examples range from droplet-droplet collisions, splashing, primary jet break-up to evaporating droplets and compressor fogging.
Bernhard Weigand is a Professor at the University of Stuttgart in Germany since 1999. Before, he worked at ABB Power Generation in Switzerland. Bernhard Weigand reserach interests are heat transfer, droplet dynamics and supersonic combustion. He is an author of more than 400 publications, holds about 40 patents and has written 6 books.
He is editor of the Int. J. Heat Mass Transfer, of the Int. Comm. Heat Mass Transfer and an elected member of acatech (National Academy of Science and Engng.) in Germany.