超燃冲压发动机燃油供给系统两相瞬变数值模拟

Numerical Simulation of Two-Phase Transient Flow in Scramjet Fuel Supply System

为揭示冲压发动机燃油介质中不同的含气量对供油系统瞬态行为的影响,在基于气体释放的物理模型和特征线算法的数学模型上,以超燃冲压发动机燃油供给系统为分析对象,对压力油箱、涡轮泵、控制阀门、输油管道、喷嘴支管等进行建模。模拟计算了在初始燃油介质中不含空气和分别含有1%与5%体积分数的空气时,供油系统分别在启泵开阀和转速阶跃下降工况下的气液两相瞬态特性。计算结果表明:在启泵开阀和转速阶跃下降的过程中,涡轮泵前的波峰压力和空泡体积会受到燃油介质中所含空气的影响,并且含气量的变化会使泵进口管段出现不同形式的压力脉动情况。

In order to reveal the effects of different air content in the fuel on the transient behavior of scramjet supply system,the simulation model of the scramjet fuel supply system which consists of the pressure tank,turbo pump,control valves,nozzles and so on,is modeled based on the physical model of gas release and the mathematical model of characteristic line method. The gas-liquid two phase transient behaviors of the system while opening the valve and stepping down the speed of the turbo pump are simulated and compared with the fuel that does not contain air and containing 1% and 5% volume fraction of air,respectively. The calculation results show that in the process of opening the valve as well as stepping down the pump speed,the maximum wave pressure and the maximum bubble volume before the turbo pump were affected by fuel oil containing different amount of air. In the meantime,the different amount of air contained in the fuel also made the pump suction pipe in different forms of pressure pulsation.