Abstract
Computational investigation of supersonic jet screech in imperfectly expanded circular jets is conducted using higher order Weighted Essentially Non-Oscillatory (WENO) scheme based solution of the axisymmetric Navier Stokes equations. The jet screech phenomenon is numerically simulated for an over expanded and an under expanded circular supersonic jet. Sound pressure levels, screech amplitude and frequency are calculated from the pressure history in the flow field and compared with values in literature. Shock cell spacings in the high speed jet are also extracted from numerical simulations and compared with that in literature. Important aspects of a screeching jet observed experimentally, like the interaction of instability waves with the shock train and the contribution of downstream propagating hydrodynamic fluctuations to the creation of the upstream moving acoustic wave in the acoustic feedback mechanism, are also captured in the present computations. The latter phenomenon has been observed experimentally but not reported previously in numerical simulations.