Comparative analysis of calculated and experimental data on an oscillating flow induced by the gasdynamic interaction of a particle with a shock layer

A supersonic flow around a cylinder with a flat end is studied for the case in which a single particle is launched from the end surface towards the incident flow. Numerical modeling is carried out with allowance for the gas-dynamic interaction of the particle with the shock layer. High-resolution, adaptive, rectangular grids are used to obtain detailed spatial and temporal flow patterns. The calculation results are compared with experimental data. It is shown that a single, large particle moving along the axis of symmetry against the incident flow and crossing the bow shock wave causes a significant restructuring of the flow and the formation of complex shock-wave and vortex structures. An important role in the formation of the flow structure is played by the formation of a toroidal vortex, which leads to an “inviscid” separation of the incident flow from the axis of symmetry. A distinctive feature of the flow around a cylinder with a flat end is the oscillatory flow regime caused by alternating stages of growth and decay of a toroidal vortex. The patterns of the oscillating flow and the oscillation frequency obtained via numerical simulation are in good agreement with the experimental data.