Equilibrium Behavior of a Tethered Autogyro: Application in Extended Flight and Power Generation
Equilibrium Behavior of a Tethered Autogyro: Application in Extended Flight and Power Generation
复制标题
系留旋翼机的平衡行为：在扩展飞行和发电中的应用
DOI：
10.1115/1.4054927
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Das, Tuhin
中科院分区：
文献类型：
--
作者：
McConnell, Jonathan;Das, Tuhin
在本文中，我们研究了系留自转旋翼机的稳定自转特性。自转现象是指转子在风场中自然旋转。我们探索系留旋翼机作为无人机（UAV）用于长时间和节能悬停应用（例如监控或监视）的可行性。系绳提供系泊作用，可用于为转子提供动力，并在适当时将风力传输到地面。这是自转的一个新颖应用。它需要一个通用的自转公式和模型，超出文献报道的范围。我们采用基于模型的方法，其中叶片单元动量（BEM）方法和悬链线力学分别用于对空气动力学和系绳进行建模。所得模型是高度非线性的，并且提出了数值方法来求解平衡。该模型根据文献中现有的模拟和实验结果进行了验证。它经过扩展，融入了与我们的应用相关的新功能，例如低转子速度、发电再生扭矩、悬链线力学与空气动力学的结合，以及随海拔高度变化的大气条件。我们描述了涉及多个自变量的一系列操作条件下的自转平衡。分析揭示了平衡状态下自转旋翼机叶尖速比的最佳工作范围。这也预示着驻扎在高空的大型旋翼机发电的可能性。
In this article, we study the characteristics of steady autorotation of a tethered autogyro. The phenomenon of autorotation refers to the natural spinning of a rotor in a wind field. We explore the viability of tethered autogyros as unmanned aerial vehicles (UAVs) for long-duration and energy efficient hovering applications, such as in monitoring or surveillance. The tether provides mooring and can be used to power the rotor and to transmit wind power to the ground when suitable. This is a novel application of autorotation. It requires a generalized formulation and modeling of autorotation, beyond what is reported in the literature. We adopt a model-based approach where the blade element momentum (BEM) method and catenary mechanics are used to model the aerodynamics and the tether, respectively. The resulting model is highly nonlinear and numerical methods are proposed to solve for the equilibria. The model is validated against existing simulation and experimental results in the literature. It is extended to incorporate new features that are pertinent to our application, such as low rotor speeds, regenerative torque for power generation, combining catenary mechanics with aerodynamics, and varying atmospheric conditions with altitude. We characterize the autorotational equilibria over a range of operating conditions involving multiple independent variables. The analysis reveals an optimal operating range of the tip speed ratio of the autogyro under equilibrium. It also indicates the possibility of power generation in large autogyros stationed at high altitudes.