D225 高次精度スキームによる超音速ジェット騒音メカニズムに関する数値解析

概要

論文の詳細を見る
Under-expaneded compressible jets are simulated at a Mach number of 1.425 and a Reynolds number of 2.2×(10)^5 to clarify the mechanism of jet sound emission. The compressible Navier-Stokes equations are solved by using an accurate numerical code with the sixth order accuracy in space. As a result, a structure with a few of shock-cells was observed, where oblique shocks exist inside the jet and a shear layer spreads outward with many vortices. The motion of these vortices seems to play a key role in sound emission. The pressure distribtion along the jet centerline gives good agreement with 3D results and experimental data in the neighborhood of the nozzle exit, where there exist a strong shock-cell structure and an axisymmetric-like flow. In addition, we can see waves that travel upstream along the jet boundary from around the first shock cell. Furthermore, there exists a discrete wave that is generated from the interaction of the jet shear layer with the oblique shock or the Mach wave.
日本流体力学会の論文
2001-07-31