Numerical investigation on the performance and combustion characteristics of a cavity based scramjet combustor with novel strut injectors

A three-dimensional numerical investigation has been carried out on the performance and combustion characteristics of a scramjet combustor with and without cavity for various strut injector configurations. The geometrical shape of the injectors considered for the present study are circle, square and rectangle. The numerical model of scramjet combustor has been discretized hexahedrally through finite volume approach using ANSYS ICEMCFD 18.0 and the necessary boundary conditions are specified in ANSYS Fluent 2021 CFD code. The three-dimensional fluid flow variations through a scramjet engine with strut-based injectors and cavity have been analyzed by solving the corresponding governing equa-tions namely continuity, momentum (Navier-Stokes) equation and energy transport equation for the non-reacting flows. In addition to the above equations species transport equation is also solved for the reacting flows. The turbulence induced in the fluid is modelled using standard K-epsilon turbulence model. The effect of injector shapes, mixing length, combustion efficiency and total pressure loss have been numerically simulated and plotted with and without cavity of a scramjet combustor. The results from the study predicted that circular injector with cavity showed better mixing characteristics and combustion characteristics compared to the rectangle and square model. The total pres-sure loss of circular injector with cavity is 5.4% higher than the other models investigated, still it is preferred because of high combustion efficiency attained with shorter span of combustor length. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A numerical investigation was conducted to analyze the performance and combustion characteristics of a scramjet combustor with and without a cavity. Different geometrical shapes of injectors were considered, including circle, square, and rectangle. The results showed that the circular injector with a cavity exhibited better mixing and combustion characteristics compared to the other injector models.