二维射流的稳定性分析与流动控制

本文在绝对／对流不稳定性的理论框架下，对二维射流的稳定性进行了数值分析。研究表明射流流场各局部剖面是对流不稳定的，不会产生整体失稳，射流频率由流场中最大增长的不稳定频率确定。将一ＮＡＣＡ０１２翼型放置于射流势流核心区中，改变翼型的偏转角度θ，可使射流剪切层频率与翼型尾流频率发生共振，整个流场产生自激振荡，加强了射流与外界流场和混合，并使射流发生矢量偏转。

Stability Analysis and Flow Control of 2-D Jet

Instability of 2 D jets has been studied by numerical analysis and experiments. The numerical analysis is based on the theoretical framework of absolute and convective instability. For 2 D jets, numerical analysis has shown that there exist convective instability, instead of absolute instability, which means no self sustained oscillation in 2 D jets. This thesis also experimentally studies a two dimensional planar jet impinging upon a NACA0012 air fold located at the jet center of the potential core region, and the change of instability of planar jet is studied.