单和双燃速固体发动机零维内弹道方程探讨

基于热力学第一定律的一般表达式,推导了单燃速和双燃速固体火箭发动机零维内弹道能量方程,并指出一些有关固体火箭发动机原理的教材中给出的单燃速零维内弹道方程在理论上并不严格一致的两个原因:一是忽略了发动机点火启动过程中燃烧室内的温度变化;二是忽略了因推进剂燃面退移控制系统所做的容积功.在一个算例中,教材中的内弹道方程计算出的点火启动时间比本文方程计算出的时间约长40%,说明不宜忽略点火启动过程中燃烧室内燃气温度的变化.

Discussion on zero-dimensional internal ballistic equations of single-and dual-burning rate solid rocket motors

Zero-dimensional internal ballistic equations for single burning rate solid rocket motor(SRM) in some textbooks on the principal of SRM were not strictly identical with each other.On the basis of the general expression of the First Law of Thermodynamics,stricter zero-dimensional internal ballistic energy equations for single-and dual-burning rate SRM were deduced,in the equations,the volume work due to the regress of burning surface of propellant was considered.The above inconsistency was explained on the basis of the energy equation of single burning rate motors.In a sample numerical test,the ignition time obtained with the equations in some textbooks may be about 40% longer than the present computational result,this shows that it might be unsuitable to ignore the variety of gas temperature in the combustion chamber during igniting process.