INIERWL FLOW AND HIRNllW CKAR4CTlHUSTIOS OF 16-INOE

A free-~et investigation of the internal-flow and burning ch~acteristics of a 16-inch ram jet was conducted in the IIACA Iawis altitude wind tunuel. Data were obtained at Mmh numbers of 1.35 and 1.73 over a range of etit-nozzle areas. A single oblique shook diffuser with no internal oontractia and a corrugated gutter-grid flame holder were employed. At both lath numbers, the inlet spike was Positicmed to allow the conicxalnose shock to inter-sect the cowl lip. Excellent agreement was observed between the cold-flow and burni ~ dMfuser total-~ssure recovery under both subcritical and su.percritioaloperation. The trends in the variation of additive dz’egand the normal-shock ~osition with mass-flow ratio agreed with those theoretically predicted. The total-~essure drop across the combustion chzmher could be predicted with reasonable aocuracy frcm the computed flame-holder and combustion momentum pressure losses. At any combustion-chamber-inletMach nmber $ either subcritical or supercritical, similar velooity distributions resulted at the “combustion-chambertilet for both the present free-jet investigation and a previously conducted oonnected-pipe investigation. As a result, combustion-chamiierperformance WES obtained in the free jet similar to that Previously obtained with a connected pipe. IN’I!RODUCTIO