Supercomputer multiscale modeling of gas mixture flows in microchannels

This paper is devoted to the modeling of flows of real gases and their mixtures in microchannels of technical systems using high-performance computing. For modeling, a multiscale two-level approach is used; it combines calculations at macro-and microlevels. The approach makes it possible to study multicomponent flows in microchannels of complex geometry in a wide range of Knudsen numbers. The parallel implementation is based on the domain decomposition method and the functional parallelism and is oriented on the use of computer systems with hybrid architecture. As an example, the problem of outflow of a nitrogen and hydrogen mixture into vacuum is considered. This example is used to study the correctness of the multiscale approach. In addition, the results of direct molecular-dynamics modeling of nitrogen flow in a nickel micronozzle are discussed, including the parallelization performance at a large number of particles (0.5 billion) and the velocity profiles in a micronozzle as a function of time.