Simulations of combustion with normal and angled hydrogen injection in a cavity-based supersonic combustor

Abstract

Combustion characteristics in a supersonic combustor with normal and angled hydrogen injection upstream of a cavity flameholder are investigated numerically using a hybrid Reynolds-averaged Navier–Stokes/large eddy simulation method acting as a wall-modeled large eddy simulation. A turbulent incoming boundary layer with thickness of δinf = 2.5 mm is considered and a recycling/rescaling method is adopted to treat the unsteady inflow. Three injection angles, α = 30°, 60° and 90°, are considered. The results show that combustion efficiency increases with increasing injection angle since the fuel jet with larger injection angle tends to benefit more from the close coupling of flow, mixing and combustion. Moreover, it is found that the heat release distribution in the streamwise direction is more uniformly for larger injection angle than for lower injection angle, which tends to result in higher total pressure recovery in the far downstream regions for larger injection angle as uniformly-distributed heat release seems beneficial to reduce the total pressure loss for the present diffusion combustion.

Effect of Different Technologies on Performance Enhancement of the Micro-Combustor for the Micro Thermophotovoltaic Application: A Review

“…However, there are few studies on the influence of cavities on slow flow combustion. Li et al proposed a novel design concept and improved the enhancement of H 2 /CH 4 , CH 4 /CO, and H 2 /CO and blended fuels by catalyst segmentation and cavity technologies in a micro channel [88][89][90]. It was found that the existence of cavity can significantly expand the stable operation range in a wide inlet velocity range for micro-reactor.…”

Dynamic combustion characteristics in a rectangular supersonic combustor with single-side expansion

“…Numerical simulations are implemented using a RANS code with k-ω SST model and an uncoupled nonequilibrium reaction solver, which was described in previous work. 24–26 The finite-rate reaction mechanism for ethylene–oxygen combustion consists of five reactive species (C 2 H 4 + 2O 2 →2CO + 2H 2 O, 2CO + O 2 →2CO 2 ) and an overall reaction model. 27 There are no expansions along the sidewalls of the entire text facility.…”

Effects of oblique and transverse injection on the characteristics of jet in supersonic crossflow

“…By hybrid RANS/LES approach, Wang el at. [29] found that the hairpin-like vortices interact with CVPs in jet plume. They pointed that as the injection angle increases, the hairpin-like vortices become larger and more, resulting in a rapid breakdown of CVPs.…”