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Direct-connect supersonic nozzle design considering the effect of combustion

2023; Elsevier BV; Volume: 133; Linguagem: Inglês

10.1016/j.ast.2022.108094

1626-3219

Bu-Kyeng Sung, Seung–Min Jeong, Jeong‐Yeol Choi,

Computational Fluid Dynamics and Aerodynamics

The effect of the chemical reaction that occurs in the flow of the supersonic nozzle is investigated to design a circular to rectangular shape transition nozzle for a rocket-type vitiated air heater. A simple method of assigning the specific heat ratio for the supersonic nozzle design is suggested. By using the specific heat ratio calculated by the one-dimensional chemical equilibrium analysis, it is confirmed applicable up to Mach 6.0 nozzle with the upstream total temperature which does not cause chemical dissociation. It is found that the effect of the species dissociation and recombination is very slight therefore it becomes negligible at a total temperature less than at which the chemical dissociation takes place. Also, regardless of the scale of the supersonic nozzle, the change in the nozzle performance due to the energy conversion is negligible. Therefore, it becomes applicable to most of the range for the direct-connect type supersonic nozzles. The designed supersonic nozzle with the approximated specific heat ratio for the direct-connect supersonic combustion experiment was confirmed to have an error of less than 1 percent. Based on this design method, the flow characteristic induced by the shape transition is reviewed in a three-dimensional simulation.