High Performance Computing in Multiscale Problems of Gas Dynamics

Abstract

The work is devoted to the organization of high performance computing in the solution of multiscale problems of gas dynamics relevant for the implementation of modern nanotechnologies. The base of the presented computing technology is a multiscale two-level approach that combines calculations at macro- and microlevels. The approach makes it possible to study micro- and nanoflows of a gaseous medium under conditions of complex geometry of technical systems used in the production cycle in order to obtain new nanomaterials and nanocoatings. Within the framework of the approach a system of the quasigasdynamic (QGD) equations and a system of the molecular dynamics (MD) equations are considered as two basic mathematical models. These models are aggregated using the method of splitting by physical processes and scales. The QGD system is solved by the finite volume method on grids of arbitrary type. The MD equations are solved according to the Verlet integration. In view of the complexity of the problem a high performance computing is used for realization of the approach. Parallel implementation of the approach is based on the methods of domain decomposition and functional parallelism and is oriented towards the use of computer systems with hybrid architecture. The implementation uses MPI, OpenMP and CUDA technologies. Testing of the developed approach and parallel tool was performed using the example of the problem of spraying the nanoparticles on a substrate. Numerical experiments confirm the effectiveness of the developed computing technology.