Abstract: Three-dimensional two-phase flow in the typical double downside 90°afterburning chamber of boron-based ducted rocket is numerically simulated by means of realizable k-ε turbulence model and one-step eddy-dissipation combustion mode1, and the ignition and combustion mode of boron particles of KING in the high-speed flow with consideration of the aerodynamic stripping effect is programmed by the UDF function of Fluent software. The results show that, when the co-swirl and counter-swirl air in the double side of inlet enters into the secondary chamber，the mixture of air and fuel finishes more fully and the combustion efficiency increases with the increase in swirl number. For particle combustion efficiency and total efficiency, the co-swirl is higher than the counter-swirl when the swirl number is less than 0.179. On the contrary, the counter-swirl is higher than the co-swirl when the swirl number is greater than 0.385, the co-swirl effect is the same as the counter-swirl effect when the swirl number is about 0.2; the ignition time of boron particles is reduced by swirling air injection, its minimum can be attained when swirl number is 0.385.

Key words: propulsion system of aviation and aerospace, boron, ducted rocketed, two-phase flow, secondary combustion