Du Changshen, Zhang Biao, Cheng Quanbao, Xu Peibao, Li Kai
Department of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China.
Micromachines (Basel). 2022 Mar 12;13(3):434. doi: 10.3390/mi13030434.
Self-oscillating systems based on thermally responsive polymer materials can realize heat-mechanical transduction in a steady ambient temperature field and have huge application potential in the field of micro-active machines, micro-robotics and energy harvesters. Recently, experiments have found that a torus on a hot surface can rotate autonomously and continuously, and its rotating velocity is determined by the competition between the thermally induced driving moment and the sliding friction moment. In this article, we theoretically study the self-sustained rotation of a hollow torus on a hot surface and explore the effect of the radius ratio on its rotational angular velocity and energy efficiency. By establishing a theoretical model of heat-driven self-sustained rotation, its analytical driving moment is derived, and the equilibrium equation for its steady rotation is obtained. Numerical calculation shows that with the increase in the radius ratio, the angular velocity of its rotation monotonously increases, while the energy efficiency of the self-rotating hollow torus motor first increases and then decreases. In addition, the effects of several system parameters on the angular velocity of it are also extensively investigated. The results in this paper have a guiding role in the application of hollow torus motor in the fields of micro-active machines, thermally driven motors and waste heat harvesters.
基于热响应聚合物材料的自振荡系统能够在稳定的环境温度场中实现热-机械转换，在微主动机器、微型机器人和能量收集器领域具有巨大的应用潜力。最近，实验发现热表面上的圆环能够自主且持续地旋转，其旋转速度由热致驱动力矩和滑动摩擦力矩之间的竞争决定。在本文中，我们从理论上研究了热表面上空心圆环的自持旋转，并探讨了半径比 对其旋转角速度和能量效率的影响。通过建立热驱动自持旋转的理论模型，推导了其解析驱动力矩，并得到了其稳定旋转的平衡方程。数值计算表明，随着半径比的增加，其旋转角速度单调增加，而自旋转空心圆环电机的能量效率先增加后降低。此外，还广泛研究了几个系统参数对其角速度的影响。本文的结果对空心圆环电机在微主动机器、热驱动电机和废热收集器领域的应用具有指导作用。
