分离螺母多种火药燃烧模型及影响因素

Model Formulation and Influencing Factors for a Separation Nut Considering the Combustion of Multiple Pyrotechnic Charges

为准确预示反推式分离螺母各运动组件的分离行为,建立考虑多种火药燃烧、热散失、密封圈摩擦力、内部机构多阶段运动的数学模型。模型模拟得到的腔内压力等分离特性参量与实测值相吻合。与忽略热散失与密封圈摩擦力的模型预测结果相比,该模型对腔内压力等参量的预测结果更接近实测值,可避免腔内峰值压力33%、内套筒峰值速度47%的过预示。使用建立的模型分析装药量对分离特性的影响规律。分析结果表明:采用新模型可适当增加药盒装药量,大幅减少快燃速Al/KClO_(4)药量,有利于提高分离可靠性、降低分离冲击。

To accurately predict the separation behaviors of the motive components of an indirect-thrust split nut and the pressure change in the combustion chamber,a mathematical model is established while considering multi-pyrotechnic charges,multi-stage motion equations of the motive components,O-ring friction,and heat loss.Compared with the experimental results,the time history of pressure is predicted with high agreement by the model.If the heat loss and O-ring friction are not considered,the predicted peak pressure and peak velocity of the inner sleeve are overpredicted by 33%and 47%,respectively.The effects of the pyrotechnic charge mass on separation behaviors are investigated using the established model.Increasing the mass of the propellant case and reducing the mass of aluminum potassium perchlorate could effectively improve the reliability of separation and reduce shock.