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 IRMA, UMR 7501
 7 rue René-Descartes
 67084 Strasbourg Cedex
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Accueil > Interactions > Interdisciplinaires > Multiphase flows : modeling and simulation

Multiphase flows : modeling and simulation    fr

- Research Team : Partial differential equations and control theory
- Contact : Philippe Helluy

Poche de cavitation derrière un projectile plongé dans de l'eau à une vitesse de 3000 m/s. Complex multiphase flows are very common in industry. Liquid-vapor flows are encountered for instance in nuclear plants, coastal engineering, industrial pumps, etc. The reliable numerical simulation of such flows is thus essential to economy and security. At IRMA, we have developed for several years, models and software for the simulation of different kinds of compressible multiphase flows: gas-particles flows (thesis of J. Nussbaum), liquid-gas flows (thesis of H. Mathis), flows with phase transition (thesis of J. Jung).

These developments are based on a long range collaboration with an EDF researcher, Jean-Marc Hérard, who participates to the direction of several IRMA PhD thesis (H. Mathis, J. Nussbaum, J. Jung). We also have a formalized french-german collaboration through the DFG/CNRS research project "Micro-Macro modeling of liquid-vapor flows". One of the objectives of the research project is to develop mathematical and numerical models for the simulation of cavitation bubbles. The cavitation is produced in a liquid flow by a local drop of pressure. The pressure drop triggers a phase transition and the appearance of vapor bubbles. The collapse of the cavitation bubbles produces strong shock waves, which may damage the environing materials.

The existing models of compressible multiphase flows are complex and involve many scales. In addition, they are strongly non-linear, which lead to difficulties in numerical software for ensuring the positivity and robustness of the schemes, together with a high precision in discontinuous waves. We have several examples today, in the multiphase community, of apparently simple test cases, even in one space dimension (!), that are not tractable without sophisticated adaptive schemes and High Performance Computing tools.

The recently started thesis of Jonathan Jung is devoted to this subject. Our challenge is to compute realistic 3D cavitation bubbles on a multi-GPU computer. The GPU cluster is available at UDS thanks to the recent success of the Equip@meso "equipex" application. Our results will be compared with the numerical results of S. Müller in Aachen and the experiments of T. Kurz, a physicist of Götingen.

Image : apparition d’une poche de cavitation derrière un projectile plongé dans de l’eau à une vitesse de 3000 m/s. Le temps varie de t=60 microsecondes (image du haut) à 420 microsecondes (image du bas).

Dernière mise à jour le 14-12-2011