基于集总参数方程的超燃冲压发动机性能计算模型

A Model Based on Lumped Parameter Method for Scramjet Performance Computation

关键词:  双模态超燃冲压发动机  总体性能  工作模态  集总参数方程  临界流量法

Key words:  Dual-mode scramjet  Performance  Operation mode  Lumped parameter method  Critical mass flow method

摘要:

针对目前常用的基于微分方程的超燃冲压发动机性能计算模型的不足,提出了基于集总参数方程的超燃冲压发动机性能计算模型。将基于控制体法的0D积分形式的守恒方程(流量连续方程、动量守恒方程和能量守恒方程)和化学动力学模型相结合,辅以临界流量法,应用于隔离段和燃烧室的1D流场计算,实现了双模态超燃冲压发动机各种模态的隔离段和燃烧室的流量平衡计算,可以捕捉到热力学喉道,确定了隔离段流动状态和燃烧室的工作模态,进而实现超燃冲压发动机全飞行包线内和全工况下的特性计算。计算结果表明,基于集总参数方程的计算模型不但能够克服基于微分方程的计算模型的缺点,而且还具有计算精度高、计算速度快、收敛性好等优点,为超燃冲压发动机总体性能计算和方案设计提供了一种很好的参考。 

Abstract:

For overcoming the disadvantages of the model based on differential equations for scramjet performance computation, a model based on lumped parameter method was presented. Intergral equations of conservation of mass, momentum, and energy of 0D control valume coupled with chemical kinetics model, combined with critical mass flow method, were used to compute the 1D flow field and to balance the mass flow of isolator and scramjet combustor in various operation modes. The thermal throat of scramjet was captured, operation states of isolator and operation modes of combustor were found, consequently the charactristcs of scramjet were computed at various states in flight envelope. Computational results show that this model can not only overcome the disadvantages of the model based on differential equations, but also has advantage of high computation precision, rapid computation speed, and good convergency. The new model provides a good reference for performance simulation.