直升机/发动机耦合模型建模与动态响应分析

Helicopter/engine coupled system modeling and dynamic response analysis

摘要:

为准确描述直升机的机动飞行动态响应过程,本研究将发动机气动热力学模型与直升机飞行动力学模型相结合,建立了一种能够反映旋翼转速波动影响的直升机/发动机耦合模型。首先,建立旋翼的飞行动力学模型和发动机的部件级气动热力学模型,然后根据功率匹配关系建立旋翼/发动机耦合模型,最终形成了包含发动机动态特性的直升机/发动机耦合模型。使用UH-60A飞行试验数据验证直升机模型的配平与动态响应结果,表明本研究建立的直升机模型能够准确描述旋翼转速变化与偏航方向力矩变化。最后,对直升机垂直跃升(bob-up)机动飞行进行仿真计算。结果表明,在垂直跃升机动过程中,直升机飞行状态迅速变化,发动机负载快速变化造成旋翼转速突变,并在偏航方向引起偏航角速度反向变化,对垂直跃升机动造成不利影响。本研究对深入认识直升机与发动机之间的耦合关系,改进直升机发动机耦合控制律设计,提高直升机机动性能具有重要的参考价值。

Abstract:

To accurately describe the dynamic response process of helicopter maneuvering flight, this study combines the engine aero-thermodynamic model with the helicopter flight dynamics model to establish a coupled model of helicopter/engine that reveals the effect of rotor speed variation. Firstly, the rotor flight dynamics model and the engine’s component-level aero-thermodynamic models are established. Then, the rotor/engine coupling model is formulated based on the power matching relationship, ultimately forming a coupled model of helicopter/engine that accounts for the engine’s dynamic characteristics. The UH-60A flight test data are used to validate the trim and dynamic response of the helicopter model. The results show that the helicopter model can accurately describe rotor speed and yaw moment changes. Finally, a simulation was performed on the helicopter bob-up maneuver flight process. The study shows that the helicopter flight state changes rapidly during the bob-up maneuver, and the rapid change in engine load causes a sudden change in rotor speed, leading to a reverse change in yaw angular velocity in the yaw direction, which has adverse effects on the helicopter’s maneuverability. This research has important reference value for a deeper understanding of the coupling relationship between helicopter and engine, improving the design of helicopter/engine coupling control laws, and enhancing helicopter maneuver flight performance.