Direct Numerical Simulation of Supersonic Gas Flow Through a Circular Cylindrical Channel

The results of the theoretical solution of the problem of braking a supersonic flow in a round pipe based on direct numerical simulation by integrating the Navier – Stokes equations without the use of additional models and empirical constants are shown. Shaded maps of density distribu- tion depending on flow parameters are presented. The flow consists of successive rhombus-shaped shock waves distributed along the entire length of the channel. It is determined that the size of x-shaped structures depends on the flow parameters. At a lower Mach number, the rhombuses have a smaller size and, accordingly, their number increases along the length of the channel. The Reynolds number also affects the size of structures, however, it is less pronounced. With a lower Reynolds number, x-shaped structures have a smaller size. It is shown that over time the flow tends to a stationary state.