Siches Jordi Ventura, Miangolarra Olga Movilla, Taghvaei Amirhossein, Chen Yongxin, Georgiou Tryphon T
Department of Mechanical and Aerospace Engineering, University of California, Irvine, CA 92697, USA.
Aeronautics and Astronautics Department, University of Washington, Seattle, WA 98195, USA.
PNAS Nexus. 2022 Nov 4;1(5):pgac251. doi: 10.1093/pnasnexus/pgac251. eCollection 2022 Nov.
A typical model for a gyrating engine consists of an inertial wheel powered by an energy source that generates an angle-dependent torque. Examples of such engines include a pendulum with an externally applied torque, Stirling engines, and the Brownian gyrating engine. Variations in the torque are averaged out by the inertia of the system to produce limit cycle oscillations. While torque generating mechanisms are also ubiquitous in the biological world, where they typically feed on chemical gradients, inertia is not a property that one naturally associates with such processes. In the present work, seeking ways to dispense of the need for inertial effects, we study an inertia-less concept where the combined effect of coupled torque-producing components averages out variations in the ambient potential and helps overcome dissipative forces to allow sustained operation for vanishingly small inertia. We exemplify this inertia-less concept through analysis of two of the aforementioned engines, the Stirling engine, and the Brownian gyrating engine. An analogous principle may be sought in biomolecular processes as well as in modern-day technological engines, where for the latter, the coupled torque-producing components reduce vibrations that stem from the variability of the generated torque.
一种典型的旋转发动机模型由一个由能源驱动的惯性轮组成，该能源产生与角度相关的扭矩。这类发动机的例子包括具有外部施加扭矩的摆、斯特林发动机和布朗旋转发动机。扭矩的变化通过系统的惯性进行平均，以产生极限环振荡。虽然扭矩产生机制在生物界也很普遍，在生物界中它们通常以化学梯度为能量来源，但惯性并不是人们通常会与这类过程联系在一起的属性。在本工作中，为了寻找消除惯性效应需求的方法，我们研究了一种无惯性概念，其中耦合扭矩产生组件的综合效应平均了环境势的变化，并有助于克服耗散力，从而允许在惯性极小的情况下持续运行。我们通过分析上述两种发动机，即斯特林发动机和布朗旋转发动机，来举例说明这种无惯性概念。在生物分子过程以及现代技术发动机中也可以寻找类似的原理，对于后者而言，耦合扭矩产生组件减少了由所产生扭矩的变化性引起的振动。
