Experimental investigation of sonic jet flows for wing/nacelle integration

An experimental study of compressible jet flows has been undertaken in a sm all transonic wind tunnel. The aim of this investigation was to realize a j et simulator in the framework of wing/nacelle integration research and to c haracterize the jet now behavior. First, free jet configuration, and subseq uently jet flow in co-flowing air stream configuration were analyzed. Flow conditions were those encountered in a typical flight condition of a generi c transport aircraft, i.e. fully expanded sonic jet flows interacting with a compressible external flowfield. Conventional experimental techniques wer e used to investigate the jet flows-Schlieren visualization and two-compone nt Laser Doppler Velocimetry (LDV). The mean and fluctuating properties wer e measured along the jet centerline and in the symmetric plane at various d ownstream locations. The results of two configurations show remarkable diff erences in the mean and fluctuating components and agree H ell with the tre nd observed by other investigators. Moreover, these experiments enrich the database for such flow conditions and verify the feasibility of its applica tion in future aerodynamic research of wing/nacelle interactions.