A Distributed Lattice Boltzmann-based Flow Simulator

The use of Lattice Boltzmann (LB) methods is interesting to describe flows through complex geometries encountered in Chemical Engineering (porous media, packed beds, multi phase flows). However, flow simulations based on LB methods can require big amounts of memory. It is not always possible to run a simulation on a single machine. Distributed computing is a solution to this problem and also accelerates the execution of the flow simulation. In the context of dynamic heterogeneous clusters, the available machines can have different computational powers. The computational power of each machine can vary during a flow simulation (because of background load). Also, the number of available machines can change. These characteristics impose the use of special technics. Dynamic Load Balancing allows the optimal use of available machines. A fault occurs when one or several machines interrupt the execution of the distributed software component they were executing. Checkpointing makes the system fault tolerant. In order to obtain a scalable software and to suppress single points of failure, a special effort is made to decentralize as much as possible the software components of the simulator. Currently, fluid flows of 400³ points (more than 9 GBytes of data) are simulated using an heterogeneous cluster of 54 machines.