Highly underexpanded rarefied jet flows

A highly underexpanded jet outflow into the background in transition and scattering regimes is studied computationally. The direct simulation Monte Carlo method Navier–Stokes equations are used. main parameters’ impact on flow analyzed. It shown that a drastic structure transformation occurs relatively narrow Reynolds numbers’ range, 5 ≤ Re L 30, featuring jet–surrounding gas interaction. At = 5, shock wave typical for degenerates completely. existing empirical expressions application estimation of characteristic dimensions regime leads to significant inaccuracy. For considered approaches based (NS) equations’ solution lead similar results nozzle region, where hydrodynamic. Nevertheless, NS approach employment assessment parameters within rarefied layers debatable.