Effect of Spacing and Canting on Twinjet Characteristics

The effect of the spacing between two centers of twin nozzles on the propagation of the Mach 0.8 twinjet is studied experimentally. The center-to-center spacings of the twin nozzles studied are equal to 3D and 5D (here, D is the nozzle exit diameter). The twinjets in parallel, inward and outward canting configurations are also studied. The inward and outward canting nozzles with a half angle of interception of 5°, 10°, and 15° are studied. For the inward canting, it is found that the peak Mach number is higher for the inward-canting twinjets than for the parallel and outward-canting twinjets. The interaction of twinjets diminishes with increase in the nozzle spacing.