旁路放气循环高速单轴涡喷发动机安装性能模拟

针对Ma3.5旁路放气循环单轴涡喷发动机,提出一种压气机旁路放气计算方法,建立基于进/排气系统特性数据库的涡轮发动机安装性能计算模型,分析压气机旁路放气对压气机共同工作线和发动机高空高速推力性能的影响,给出压气机旁路放气量的调节原则,计算发动机安装性能、进/排气安装阻力沿飞行轨迹的变化规律。计算结果表明:当飞行马赫数大于2.3后需打开压气机旁路放气,旁路放气阀门面积和放气流量均随着飞行马赫数的增大基本呈线性增大趋势;通过压气机旁路放气,可显著改善单轴涡喷发动机在高空高速飞行条件下的稳定性和安装推力性能,在飞行马赫数3.0附近,可实现安装推力提高30%以上;在跨声速至飞行马赫数2.0区间内,推力安装损失最大,约为非安装推力的25%～30%。

Simulation of Installed Performance of High-SpeedSingle-Shaft Turbojet with Bypass Bleed Cycle

The turbine engine installed performance simulation model based on the inlet/exhaust system characteristics database was developed, and an approach to model the compressor bypass bleed was proposed, for a Mach 3.5 single-shaft turbojet engine with bypass bleed cycle. The effects of compressor bypass bleed on the compressor work line and engine thrust performance under high-altitude high-speed conditions were analyzed, the adjustment principle for the compressor bypass bleed was put forward, and variation of the engine installed performance and inlet/exhaust system installation drags along the flight trajectory was simulated. The simulation results show that the compressor bypass bleed should be opened when the flight Mach number exceeds 2.3, and both the valve area and air mass flow of the bypass duct are essentially proportional to the flight Mach number. Through the compressor bypass bleed, the stability and installed thrust performance of the single-shaft turbojet under high-altitude high-speed conditions were significantly improved, and the installed thrust can be increased by more than 30% at the flight Mach number of about 3.0. The installation loss of thrust is maximized, about 25%~30% of the uninstalled thrust, between transonic speeds to the flight Mach number of 2.0.