旋转爆震波发动机二维数值模拟

Two-dimensional numerical simulation of rotating detonation wave engine

关键词:  旋转爆震波发动机  解耦方法  起爆过程  性能分析

Key words:  Rotating detonation wave engine  Uncoupled non-equilibrium method  Detonation initiation  Performance analysis

摘要:

采用一种改进的化学非平衡流解耦方法对Euler反应流方程解耦处理,对流项采用五阶WENO格式离散,化学反应源项的刚性采用简化的隐式方法处理,时间步进采用二阶精度的Runge-Kutta方法,对H2/Air预混气旋转爆震发动机内流场进行了二维数值模拟。模拟结果给出了不同发动机尺寸条件下的详细起爆过程,结果表明当发动机尺寸小于临界直径时无法成功起爆;详细分析了流场结构和爆震波形状,旋转爆震波的传播速度与理论预测值吻合;性能分析结果表明在喷注总压低于燃烧室平均压力时仍可实现推进剂喷注,没装尾喷管的情况下发动机比冲达到176.5s。

Abstract:

An improved uncoupled solver of non-equilibrium flow was used to split the Euler equations for a reacting flow.Inviscid flux was calculated with fifth-order WENO scheme.Simplified implicit formulation was adopted to deal with the stiffness generated by the chemical reacting source term of species equations.Time integration was performed with two-order TVD Runge-Kutta scheme.Flow field of H2/Air rotating detonation wave engine was calculated.The initiation processes of rotating detonation at different engine size were analyzed particularly.When the diameter of engine is less than the critical size,we could not get a rotating detonation wave.Calculated flow field and the inclination of rotating detonation wave were detailed.The rotating velocity nearly equals the C-J speed.Performance analysis indicates that when the injection pressure is less than the chamber pressure,propellant could also be injected into combustor successfully.Although there is no nozzle after the straight combustor,the specific impulse of engine reaches 176.5s.