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从共轴双旋翼直升机的工程实际出发,建立了共轴式直升机上下旋翼非定常气动特性的计算模型.引入Leishman-Beddoes指数函数的半经验公式,建立了二维翼型非定常气动模型;分别从固定尾迹和自由尾迹,引入干扰因子到动态入流三种方法出发,建立了反映共轴双旋翼直升机上下旋翼气动干扰的诱导速度模型;从跷跷板式旋翼的挥舞动力学方程出发,利用4阶Runge-Kutta算法求解桨叶刚性挥舞角的数值解.通过计算分析,得到了悬停和前飞状态,总距突增时上下旋翼升力的动态响应特性,以及总距突增时上下旋翼桨叶铰链力矩的响应特性.
Based on the engineering practice of co-rotating twin-rotor helicopters, a computational model of the unsteady aerodynamic characteristics of co-axial helicopters was established. The semi-empirical formula of Leishman-Beddoes exponential function was introduced to establish the unsteady aerodynamic model of two- Starting from fixed wake and free trail, introducing disturbing factor into dynamic inflow, the induction velocity model is established to reflect the aerodynamic interference of the upper and lower rotor of the coaxial twin-rotor helicopter. Based on the waving kinetic equation of the seesaw rotor, -Kutta algorithm to solve the rigid blade waving angle.The dynamic responses of the upper and lower rotor blades in hovering and forward flying state are obtained by calculation and analysis, Response characteristics of torque.