The facts & the project
Turbulent ﬂows involving a number of ﬂuids (liquid or gas) are of huge interest in a variety of areas of application such as nuclear power station cooling, the optimisation of fuel consumption in a motor, the fabrication of new materials for aeronautic and space vehicles or the puriﬁcation of steel.
In all of these conﬁgurations, the dynamic of the ﬂow and the transfers of mass and heat are intimately connected to the coupling between a deformable interface, which splits into drops or bubbles, and the speeds of and pressures in each of the ﬂuids.
Direct numerical simulation (DNS) makes it possible to reproduce the changes in the interfaces, to describe the variation in the spatial-temporal scales of the interfacial structures and predict the sizes of the drops or bubbles generated and the interfacial areas involved, which is the ﬁrst parameter of the combustion in a motor, for instance.
The team under Professor Stéphane Vincent, at the MSME (Modélisation et Simulation Multi-Echelle) laboratory, working with a number of laboratories in the context of the ANR Modemi project, produced simulations of these ﬂows.
For the ﬁrst time at an international level, a number of computing codes were compared with the aim of analysing the coupling of the turbulence with a highly deformable interface, covering conﬁgurations where there had been no experiments.
This type of simulation makes it possible to improve understanding and control over turbulent interface issues. These computations were carried out on meshes containing 100 million to 8 billion points on 1,000 to 10,000 cores, using all GENCI computers: Curie (1.2 million hours) at TGCC, Ada (400,000 hours) and Turing (12 million hours) at Idris, and Jade (640,000 hours) at Cines.