Elliptic jet control with cross-wire

Abstract

The effect of cross-wire on the aerodynamic mixing of circular and elliptic sonic jet flow fields is studied experimentally in the presence of favourable pressure gradient at the orifice exit. The cross-wire is found to reduce the amplitude of pitot pressure oscillation drastically, and thus weakens the shock cell structure in the jet core. In the case of elliptic jets, the effectiveness of cross-wire is found to be dependent on its location at the orifice exit. For lower aspect ratio jets (AR 2), cross-wire along the major axis proves to be more effective in enhancing mixing, but as the aspect ratio increases to higher values (AR 6), cross-wire along the minor axis becomes more effective in promoting the jet mixing. The pressure profile results indicate that the cross-wire located on the major axis advances the axis-switching phenomenon, while the cross-wire along the minor axis shifts the axis-switching location further downstream compared to uncontrolled jet. The jet bifurcation caused by the cross-wire has been captured in the shadowgraph pictures.