Combustion Characteristics of a Solid Fuel Ramjet with Secondary Air Intake in Combustion Chamber

In response to the low combustion rate and efficiency caused by diffusion combustion in solid fuel ramjet, a solution involving a solid fuel ramjet withdual-side secondary air intake is proposed to improve combustion performance. A combustion model for the ramjet is established based on Standard k-Ε turbulence model and vortex dissipation equations. Simulation calculations are conducted to analyze the internal flow field, burning surface recession rate, and combustion efficiency for both the basic ramjet model (without side air intakes) and the dual-side secondary air intake ramjet model. And the influence of bypass ratio on the performance of dual-side secondary air intake ramjet is investigated. The results indicate that the internal flow field of dual-side secondary air intake ramjet exhibits new flow field characteristics such as secondary recirculation zone and swirling zone, which contribute to enhanced mixing and combustion. Combustion efficiency and specific impulse (Isp) increase first and then decrease with the increase in bypass ratio, reaching their highest values when the bypass ratio achieves 60% . Compared to the basic ramjet model, the combustion efficiency of dual-side secondary air intake ramjet is increased by nearly 40%, and its specific impulse is increased by 12. 09% at a bypass ratio of 60% . Overall, the thrust increases with the increase in bypass ratio, with the maximum thrust being observed at a bypass ratio of 60% . However, the thrust increment diminishes gradually as the bypass ratio continues to increase. © 2024 China Ordnance Industry Corporation. All rights reserved.