Numerical study of the influence of annular width on the rotating detonation wave in a non-premixed combustor

A numerical study of three-dimensional non-premixed rotating detonation combustor is performed to investigate the effects of combustor annular width (w) on the formation process of rotating detonation wave, characteristics of flow field, propagating stability and propulsive performance of combustor. Fixing the outer diameter and changing the inner diameter, three annular widths (i.e., 5mm, 8mm and 12mm) are investigated. The results show that annular width plays a crucial role to affect the behavior of rotating detonation wave. Dual-wave mode is obtained in case of w = 5mm while single-wave mode is obtained in cases of w = 8mm and 12mm. Additionally, the highest height of rotating detonation wave is observed in case of w = 8mm, which leads to the largest pressure peak. Besides, great fluctuation of detonation wave height is observed in case of w = 12mm. Furthermore, accumulated pressure wave appears in each case and its intensity is an important factor for the generation of new detonation wave front. Moreover, as the increase of annular width, the thrust and specific impulse both decrease. The largest thrust and specific impulse are both obtained in case of w = 5mm, which are 79.16N and 2692.52s respectively. (C) 2020 Elsevier Masson SAS. All rights reserved.