Numerical Analysis of Fan Duct Flow with the Acoustic Panel in Jet Engine

Abstract

Noise suppression is of importance for jet engines. Acoustic panels installed in the fan duct can reduce the noise emission while it induces the pressure loss. In order to achieve the suppression of the noise emission and the low duct loss simultaneously, we have designed new acoustic panel and conducted implicit large eddy simulations of the duct flow with the panel in this study. Since the Mach numbers in the duct and the hole of the cavity are extremely different, we have employed an all speed Roe scheme for compressible flow solvers. The turbulence is induced by a roughness block. We have found that the turbulent boundary layer becomes thinner just downstream of the hole in the duct since a part of the turbulence goes into the cavity.