Study on Unsteady Combustion Behaviors of AP/HTPB Base-Bleed Propellant under Transient Depressurization Conditions
As the base-bleed projectile flies away the muzzle,the environmental pressure in the base-bleed combustor suddenly drops and the AP/HTPB base-bleed propellant is in the state of intense unsteady combustion.To further study unsteady combustion characteristics of base-bleed propellant,the experimental device of semiclosed bomb vessel is designed and transient depressurization conditions of the muzzle are simulated.The experiments of transient combustion characteristics of the base-bleed propellant under high depressurization rate are carried out by means of high speed digital camera system.In the experiments,the combustion chamber pressure of semi-closed bomb vessel is controlled in the range of 20~90MPa and the depressurization rate is controlled in the range of 400~1.12×104MPa/s.The experimental results indicate that,the blow-away effect between different phases is intense under rapid depressurization condition,leading to thickening reaction layer.The thermal feedback of the solid surface decreases and combustion reaction of gaseous phase is so difficult to maintain that it begins to extinguish rapidly.However,the thermal decomposition of solid phase is still continuing and the yellow fog can be observed in the combustor nozzle.Depending on the maximum pressure and depressurization rate of the combustion chamber,the transient combustion of AP/HTPB base-bleed propellant displays three main patterns which are automatic reignition,oscillating combustion(critical type)and permanent extinguishment.If initial pressure of combustion chamber before depressurization is larger or the depressurization rate is smaller,the base-bleed propellant tends to automatically reignite earlier and the combustion process is more stable after losing stability.Three unsteady combustion behaviors are preliminarily analyzed based on thermal feedback.
Base-bleed propellant AP/HTPB unsteady combustion high depressurization rate oscillating combustion
Yonggang Yu Yanhuang Zhou Chunyi Lu Xiaochun Xue
Nanjing University of Science & Technology,Nanjing,China
国际会议
桂林
英文
1-9
2013-07-16（万方平台首次上网日期，不代表论文的发表时间）