Numerical Analysis of the Mach Wave Radiation in an Axisymmetric Supersonic Jet

축대칭 초음속 제트에서의 마하파 방사에 관한 수치적 연구

  • 김용석 (한국과학기술원 대학원 기계공학과 항공우주) ;
  • 이덕주 (한국과학기술원 기계공학과 항공우주)
  • Published : 2000.06.22

Abstract

An axisymmetric supersonic jet is simulated at a Mach number of 1.5 and a Reynolds number of $10^5$ to identify the mechanism of sound radiation from the jet. The present simulation is performed based on the high-order accuracy and high-resolution ENO(Essentially Non-Oscillatory) schemes to capture the time-dependent flow structure representing the sound source. In this simulation, optimum expansion jet is selected as a target, where the pressure at nozzle exit is equal to that of the ambient pressure, to see pure shear layer growth without effect of change in jet cross section due to expansion or shock wave generated at nozzle exit. Shock waves are generated near vortex rings, and discernible pressure waves called Mach wave are radiated in the downstream direction with an angle from the jet axis, which is characteristic of high speed jet noise. Furthermore, vortex roll-up phenomena are observed through the visualization of vorticity contours.

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