Numerical investigation on H2/Air non-premixed rotating detonation engine under different equivalence ratios. (13th January 2020)

• Record Type: Journal Article
• Authors: Zheng, Hongtao; Meng, Qingyang; Zhao, Ningbo; Li, Zhiming; Deng, Fuquan
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 3(2020)
• Page Start: 2289
• Page End: 2307
• Publication Date: 2020-01-13
• Subjects: Numerical simulation -- Rotating detonation wave -- Combustion -- Equivalence ratio -- Propagation stability; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.11.014
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this paper, three-dimensional numerical simulations are performed to investigate the formation and propagation characteristics of rotating detonation wave in a non-premixed engine. By changing the mass flow rate of H2 and fixing air mass flow rate, the effects of equivalence ratio involving fuel lean and rich operating conditions are mainly discussed. Numerical results show that equivalence ratio plays a very critical role in the formation process and propagation mode, which further affects the propulsion performance of rotating detonation engine significantly. For current numerical geometry and operating conditions, the lean limit of equivalence ratio for formatting a stable RDW is about 0.4, dual-wave mode (at equivalence ratio of 0.6, 0.8, 1.0 and 1.4) and single-wave mode (at equivalence ratio of 1.2) are obtained, respectively. When equivalence ratio is 1.0, rotating detonation engine can exhibit excellent operating performance with the shortest formation time, best propagation stability, middling class thrust and specific impulse. Besides, the pressure contour analysis indicates that the effects of equivalence ratio and mass flow rate of H2 on the collision strength and times during the re-initiation process are the main mechanisms for determining the formation possibility and propagation mode of rotating detonation wave. Besides, the intensity of accumulated pressure wave and distributions of equivalence ratio are two important factors for the generation of new detonation wave front. Furthermore, it is also detected from the comparisons of the propulsion performance that the effects of equivalence ratio on thrust and specific impulse under fuel lean conditions are more significant than those under fuel-rich conditions. Highlights: Detailed formation process under various equivalence ratios is investigated. Insights into physical mechanism of new detonation front generation. Effects of equivalence ratio on RDW propagating stability is explored. Propulsion performance of RDE under various equivalence ratios is compared.