Shock associated noise generation in curved turbulent Coanda wall jets

Abstract

Curved three-dimensional turbulent Coanda wall jets are present in a multitude of natural and engineering applications. The mechanism by which they form a shock-cell structure is poorly understood, as is the accompanying shock-associated noise (SAN) generation. This paper will discuss these phenomena from both a modeling and experimental perspective. The Method of Characteristics will be used to rewrite the governing hyperbolic partial differential equations as ordinary differential equations, which will then be solved numerically using the Euler predictor-corrector method. The effect of complicating factors such as radial expansion and streamline curvature on the shock-cell location predictions will be discussed. Comparison of the theoretical calculations of the shock wave structure with associated schlieren flow visualization results will be presented. Related acoustical measurements will also be communicated. In this way, critical flow characteristics for shock-cell formation will be identified, and their influence on SAN discussed.