Dynamic Modeling of Autorotation for Simultaneous Lift and Wind Energy Extraction
Dynamic Modeling of Autorotation for Simultaneous Lift and Wind Energy Extraction
复制标题
同时升力和风能提取的自转动态建模
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Sadaf Mackertich
中科院分区：
文献类型：
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作者：
Sadaf Mackertich
本论文的目标是开发一种自转多体动力学模型，以研究其在能量收集中的应用。进行自转的旋翼称为自转旋翼机。在自转模式下，转子无动力，其与风的相互作用产生向上的推力。自转旋翼机的理论最初是为了实现低速安全飞行而研究的，后来用于直升机在发动机故障下的安全下降。这一概念有可能被用作收集高空风能的一种手段。自转本质上是一个动态过程，需要详细的模型来表征。
现有的自转模型假设转子角速度恒定的稳定运行条件。该模型提供空间平均空气动力和扭矩。虽然这些稳态自转模型用于为本文开发的动态模型奠定基础，但后者使用拉格朗日公式来确定运动方程。叶片上产生推力、面内扭矩和面外扭矩的空气动力学效应在拉格朗日框架内被建模为非保守力。为了合并瞬时空气动力，去除了上述空间平均。所得模型是因果模型，由微分方程组组成。为了研究能量收集操作下的动力学，添加了额外的面内再生扭矩来模拟发电机的效果。这种再生制动的空气动力学效应已纳入模型中。此外，动力学模型放宽了小扑动角的假设，叶片的周期性扑动行为是由动力学自然产生的，而不是假设傅里叶展开。动态模型可以研究由于操作条件变化或风速等外部影响而导致的瞬态。它还有助于深入了解力和扭矩波动。
进行模型验证是为了确保动态模型产生与先前工作中报告的类似的稳定运行条件。此外，还评估了能量收集下的自转行为。该论文还探讨了在从盛行风中提取能量的同时实现足够升力的可行性。应用一系列再生扭矩来确定最佳能量状态。最后，通过结合利用悬链线模型的系绳来建模完整的高空能量收集系统。总体而言，本文支持了这样的假设：当配备适当的控制系统时，系留旋翼机可以支撑其重量，同时从强风场收集能量。
The goal of this thesis is to develop a multi-body dynamics model of autorotation with the objective of studying its application in energy harvesting. A rotor undergoing autorotation is termed an Autogyro. In the autorotation mode, the rotor is unpowered and its interaction with the wind causes an upward thrust force. The theory of an autorotating rotorcraft was originally studied for achieving safe flight at low speeds and later used for safe descent of helicopters under engine failure. The concept can potentially be used as a means to collect high-altitude wind energy. Autorotation is inherently a dynamic process and requires detailed models for characterization.
Existing models of autorotation assume steady operating conditions with constant angular velocity of the rotor. The models provide spatially averaged aerodynamic forces and torques. While these steady-autorotation models are used to create a basis for the dynamic model developed in this thesis, the latter uses a Lagrangian formulation to determine the equations of motion. The aerodynamic effects on the blades that produce thrust forces, in-plane torques, and out-of-plane torques, are modeled as non-conservative forces within the Lagrangian framework. To incorporate the instantaneous aerodynamic forces, the above-mentioned spatial averaging is removed. The resulting model is causal and consists of a system of differential equations. To investigate the dynamics under energy-harvesting operation, an additional in-plane regenerative torque is added to simulate the effect of a generator. The aerodynamic effects of this regenerative braking is incorporated into the model. In addition, the dynamic model relaxes assumptions of small flapping angles, and the periodic flapping behavior of the blades are naturally generated by the dynamics instead of assuming Fourier expansions. The dynamic model enables the study of transients due to change in operating conditions or external influences such as wind speeds. It also helps gain insight into force and torque fluctuations.
Model verification is conducted to ensure that the dynamic model produces similar steady-operating conditions as those reported in prior works. In addition, the behavior of autorotation under energy harvesting is evaluated. The thesis also explores the viability of achieving sufficient lift while extracting energy from prevailing winds. A range of regenerative torques are applied to determine the optimal energy state. Finally, a complete high-altitude energy harvesting system is modeled by incorporating a tether utilizing a catenary model. Overall, the thesis lends support to the hypothesis that a tethered autogyro can support its weight while harvesting energy from strong wind-fields, when augmented with appropriate control systems.
自旋翼机理论在机载风能提取中的应用
DOI：
10.1115/dscc2013-3840
发表时间：
2013
期刊：
Proceedings of the 2013 ASME Dynamic Systems and Control Conference
影响因子：
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作者：
Rimkus, Sigitas;Das, Tuhin
通讯作者：
Das, Tuhin