Computational Aeroacoustics Applied to Coherent-Flow Jet Structures

In the last several years, there has been a growing demand to cope with the increasing population by expanding transportation networks and introducing new ideas. Air transportation introduced high-speed civil transport (HSCT). However, compliance with the Federal Aviation Regulations, FAR 36-Stage 3-community noise standard is one of the major factors to inhibit these plans. Accurate computational methods for noise prediction, especially for the dominant supersonic jet component, are in great demand. This book focuses on the acoustic fields of axisymmetric supersonic free jets subject to a prescribed input excitation as a means of generating coherent structures and a potential noise control method. The flow field is divided into a mean field, which is time independent, and a perturbation field, which is time dependent. The mean field is obtained either from measurements. An input excitation is added to this mean field, and the perturbations are computed using the linearized Euler equations (LEE). High-order accurate numerical scheme is utilized. Different kinds of nonreflecting boundary conditions are used at the inflow and outflow boundaries to prevent spurious waves.