Experimental investigation of the effect of extended cowl on the flow field of planar plug nozzles

Autor: S. Mohammed Ibrahim, Rohit Panthi, Rakesh Kumar, Aqib Khan
Rok vydání: 2019
Předmět:
Zdroj: Aerospace Science and Technology. 88:208-221
ISSN: 1270-9638
DOI: 10.1016/j.ast.2019.03.011
Popis: Plug and ramp nozzles offer many advantages over the conventional converging-diverging counterpart and have received much attention in the recent decades. Variants of plug nozzles have been investigated for a wide range of operating conditions. The performance of these nozzles is dependent on the flow development on the plug or ramp surface, which in turn is greatly influenced by the cowl geometry. Experiments are conducted to study the planar plug nozzle flowfield for Mach 1.8 and 2.2 using half nozzle geometry. The work primarily focuses on the influence of the cowl length on the flow evolution on the plug surface at different nozzle pressure ratios (NPRs). The cowl of the outer nozzle is extended to 10, 30, 50 and 100% of the full plug length. This allows the supersonic flow to partially expand internally ahead of the throat section. Schlieren images are used to visualize the wave structure at different pressure ratios for different cowl lengths. For low NPRs, the nozzle with extended cowl behaves more like a conventional planar nozzle with strong shock waves. It is observed that the cowl length influences the pressure distribution on the plug surface only for low NPRs. The effect of side walls on the flow field of planar plug nozzles is also studied.
Databáze: OpenAIRE
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