Experimental Study of the Environmental Flow-field of Two Impinging Model Scale Jets

The flow-field of dual model scale jets impinging onto a flat ground plane is experimentally investigated. In a tandem configuration, the front jet consists of a convergent nozzle operating sonically while the rear jet consists of a converging-diverging nozzle operating at a fully expanded jet Mach number of 1.34. The goal of this work is to simulate the environment produced by jet impingement during a hover or vertical landing of a short take-off and vertical landing (STOVL) aircraft. The experimental model includes a pressure instrumented generic lifting surface and an adjustable height ground plane which is also instrumented with surface pressure taps. Other measurements in the study include chalk flow visualization, optical shadowgraphy, and wall jet surveys with a pitot rake.