航空发动机低压转子功率平衡与动态响应研究

Power Balance and Dynamic Response of an Aero-Engine Low-Pressure Rotor

摘要: 针对航空发动机低压转子在不同飞行条件下功率传递与动态响应分析问题，建立了包含入口状态、燃烧室热力动态、高压转子动态、低压涡轮等效功率、风扇/低压压气机负载及低压转子动力学的简化模型，并同步计算涡轮进口温度和等效喘振裕度等安全状态。以T-MATS环境下的JT9D发动机模型作为动态参考，设置代表工况及不同高度、马赫数组合的12组工况进行仿真。结果表明，在$H=3000m$ 、$Ma=0.3$ 的代表工况下，燃油空气比由0.0187增至0.0197后，低压转子转速由3542.65 rpm升至3715.28 rpm，增量为172.62 rpm，阶跃后归一化剩余功率逐渐趋近于零。多工况下最高涡轮进口温度约为1386.35 K，最低等效喘振裕度约为24.12%，均未触及设定安全边界。结果说明，该模型能够从功率平衡角度描述燃油变化引起的低压转子动态过程，并反映不同飞行条件对转速响应和安全状态的影响。

Abstract: A simplified model is developed to investigate the power transfer and dynamic response of an aero-engine low-pressure rotor under different flight conditions. The model incorporates inlet-state calculation, combustor thermal dynamics, high-pressure rotor dynamics, equivalent low-pressure turbine power, fan/low-pressure compressor loads, and low-pressure rotor dynamics, while also providing turbine inlet temperature and equivalent surge margin as safety-related outputs. A JT9D engine model implemented in the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) is used as a dynamic reference. Simulations are conducted for a representative operating condition and for 12 combinations of flight altitude and Mach number. At $H=3000m$ and $Ma=0.3$ , increasing the fuel-air ratio from 0.0187 to 0.0197 raises the low-pressure rotor speed from 3542.65 rpm to 3715.28 rpm, corresponding to an increase of 172.62 rpm, while the normalized residual power gradually approaches zero after the transient. Across the investigated operating conditions, the maximum turbine inlet temperature is approximately 1386.35 K and the minimum equivalent surge margin is approximately 24.12%, both remaining within the prescribed safety limits. The results show that the proposed model can describe the low-pressure rotor dynamic process caused by fuel changes the perspective of power balance and capture the effects of flight conditions on rotor-speed response and safety-related states.