Effect of corrugation on limiting arc-tab mixing performance

Abstract

The effect of corrugation on the mixing promoting performance of a limiting arc-tab has been assessed by studying the decay of a Mach 1.76 jet emerging from a convergent-divergent nozzle, with a limiting arc-tab, with and without corrugation, running along a diameter at the nozzle exit, operated at nozzle pressure ratios of 4.5 and 8. Uncontrolled jet was also studied for comparison. The physics behind the difference between the mixing caused by the uncorrugated and corrugated tabs in the presence of adverse and favorable pressure gradient is addressed using the shadowgraph images of the jet core as the main source and the centerline pitot pressure decay as the supporting material. The results show that the mixing promotion caused by the tabs leads to the shortening of the third and fourth shock cells in the jet core. This can be regarded as an advantage from the screech suppression point of view.