舰面旋翼瞬态气动弹性响应及其控制研究

Excessive transient aeroelstic responses of shipboard helicopter rotor blades during engagement and disengagement can threaten the safty of shipboard helicopters in landing and taking off operations. To investigate the transient aeroelastic dynamics of helicopter rotors in shipboard environment, a comprehensive rotor modeling is derived, which includes the blade structural model, rotor kinematics, airfoil aerodynamics, rotor induced velcoity model and blade drop stop impact model. This comprehensive rotor modeling is coupled with a fuselage and ship model. A model to describe the air flow over the helicopter dock is introduced to derive the comprehensive modeling of this system. This modeling is utilized to explore the essence and disciplines of the phenomenon in the transient aeroelastic responses and the influence of the deterministic paramters on the responses. Gurney flaps are introduced as the control method to reduce the transient response. The mechanism of the flow control associated with the Gurney flap is explored and the aerodynamic modeling of the airfoil with the Gurney flap is derived. The control laws are designed to control the motions of the Gurney flaps to reduce the excessive flapping of the rotor blades. The platform with six degrees-of-freedom is utilized to simulate the ship motions. A model ship is used to generate the air flow over the helicopter dock. The wind tunnel test is utilized to investigate the effect of ship motions and the flow over helicopter dock on the transient responses. The rotor equipped with the Gurney flaps is utiltized to verify the effectiveness to control the transient aeroelastic responses of helicoter rotors during engagement and disengagement operations in the test.

直升机起动和停转过程中，过大的旋翼瞬态气动弹性响应对舰载直升机起降安全构成严重威胁，为研究舰面环境直升机旋翼的瞬态气弹动力学问题，先建立旋翼的综合动力学模型，包括旋翼结构、运动、气动、诱导速度和桨叶与挥舞限动装置碰撞等模型。然后将旋翼与机体和舰船模型相耦合，引入舰面流场模型，建立该系统的综合动力学模型，以揭示舰面旋翼瞬态气动弹性响应现象的本质和规律，并探讨主导旋翼瞬态气动弹性响应的舰面环境参数和影响程度。最后引入格尼襟翼作为旋翼瞬态气弹响应的控制方法，探讨其流动控制机理和规律，建立加装格尼襟翼翼型气动模型，并设计控制策略，抑制旋翼挥舞方向过大的瞬态气动弹性响应。采用六自由度运动平台模拟舰船运动、模型舰船模拟舰船直升机甲板上方流场，通过风洞实验研究舰面环境对旋翼瞬态气动弹性响应的影响程度，在此基础上加装格尼襟翼，测试格尼襟翼用于控制舰面旋翼瞬态气动弹性响应的有效性。

舰载直升机旋翼起动和停转过程中，受到较强舰面来流时，易出现旋翼桨叶因挥舞过大与机体相碰事故。为了探究舰面旋翼瞬态气弹响应问题的本质和控制方法，开展了直升机/舰船系统综合动力学建模、舰面环境旋翼瞬态气动弹性响应现象的本质和规律探讨、舰面旋翼瞬态气动弹性响应控制研究和舰面旋翼瞬态气弹响应相关试验等方面研究。重点针对直升机/舰船系统综合动力学模型、舰面旋翼综合动力学模型验证、舰面流场特征、舰面环境直升机甲板典型尺寸对直升机旋翼起动和停转过程中的旋翼气动弹性响应、典型参数对舰面旋翼瞬态气弹响应影响、基于格尼襟翼和舰面射流的舰面旋翼瞬态气弹响应控制以及模型桨叶扬起下坠碰撞响应、舰面流场和模型舰面旋翼瞬态气弹响应等试验进行了深入研究。通过研究表明，舰面复杂的气动环境及舰船运动对旋翼起动和停转过程瞬态气弹响应影响明显，通过加装主动格尼襟翼可有效降低旋翼起动过程过大的瞬态挥舞负向位移，通过优化控制律可进一步提升控制效果，提出的在舰船加装射流方法为抑制舰面旋翼瞬态气弹响应提供了一种新方法。