Study of Rarefied Flow Around Rectangular Cylinder Using DSMC

The rarefied flow around a rectangular cylinder is studied using in-house developed DSMC solver. When the flow becomes rarefied, the nature of the shock system will be affected and also the cases with high Knudsen number will be difficult to simulate using Navier–Stokes equation. 2D-DSMC solver is developed to study high Knudsen number flows or rarefied flow regimes. Particle collisons are treated by variable hard sphere model with Larsen–Borgnakke model for rotation which is adopted in the present code. In the present simulation, a rectangular cylinder of 6 × 6 mm is investigated for a range of Mach number 2.0–5.0 with different Knudsen numbers. The result indicates that the shock gets smeared with increasing Knudsen number. Also, the increasing Knudsen number shows that pressure load acting on the rectangular cylinder gets reduced.