Modelling and Optimisation of Arrays of Novel Bio-Mimetic Energy Harvesters. Energy: Fluid Dynamics and Aerodynamics

研究领域：能源、流体动力学、空气动力学。能量收集是一种很有前途的将环境能量转化为电能的技术。为了普及收割机，提高它们的效率至关重要。改进的空间首先在于从环境中获得最大的机械能，其次在于将机械能有效地转化为电能。这个项目首次提出使用模仿白杨叶子的仿生收割机作为利用风能的一种方式。所讨论的装置是一个颤振板，它利用平移自由度和旋转自由度之间的耦合来经历高振幅振荡，即使在风速低的情况下也是如此。为了从这种运动中产生电能，使用了压电陶瓷致动器。压电陶瓷发电的主要问题是单个器件产生低电压，交流电输出，这意味着几乎所有来自此类器件的能量在转换为有用的直流电时都损失了，损失是由于整流器中二极管的电压降。上述情况使得收割机在现实世界中的应用具有挑战性。为了解决这个问题，将部署收割机阵列，其中叶子将被设计成同步移动，增加电压输出，从而使固有的有损转换过程更加有效，从而为这种形式的能量收集开辟了制造实用设备的可能性。从军事设施到家用气体流量计，这种技术的应用非常广泛。尽管过去几年在能量收集领域开展了广泛的活动，但大多数研究都集中在某些配置的试错测试上，很少注意对系统行为进行彻底的学术调查。杨木叶型板显示的动态行为类似于一个被称为飞机机翼的气动弹性颤振。适应现有的知识，以优化收割机将是第一步建设一个有效的设备。总的来说，该方案的目标是开发类似颤抖的白杨叶的仿生流体弹性能量收集器阵列。本研究是一个具有较高学术意义的前期项目。研究目标如下：a.实验研究了不同流动条件下杨树单叶型颤振的振动，并以动力系统的精神建立了相应的数学模型。设计一个非线性收割机，在广泛的环境风条件下具有稳定的振幅或频率响应。b.将单个收割机连接成阵列，并研究元件之间的水动力和结构相互作用，以优化系统性能。阵列中收割机同步的实现程度将与基于压电陶瓷发电的需求和效率有关。当系统暴露于稳定气流和网格湍流时，通过风洞试验验证开发的模型。d.拟进行的实验及模拟计划的结果将会公布，以作为申请EPSRC拨款的依据。同时，将全面考虑部署收获阵列的商业可行性。从以下主题中选择研究成果：1 -能源2 -流体动力学和空气动力学

Research Areas: Energy: Fluid Dynamics and Aerodynamics.Energy harvesting is a promising technology for converting environmental energy to electricity. To make harvesters widespread, it is crucial to increase their efficiency. The room for improvement lays first, in getting maximum mechanical energy from the environment and second, in the efficient conversion of mechanical energy to electricity. This project for the first time suggests using a bio mimetic harvester imitating an aspen leaf as a way of harnessing the wind energy. The device in question is a fluttering plate which utilises coupling between translational and rotational degrees of freedom to undergo high amplitude oscillations, even when the wind speed is low. To generate electric energy from this movement, piezoceramic actuators are used. The main problem with piezoceramic generation is that individual devices produce a low voltage, alternating current output, meaning that nearly all of the energy from such devices is lost on conversion to useful dc current, losses are due to a voltage drop across diodes in the rectifier. The above makes real world application of the harvesters challenging. To resolve the problem, harvester arrays will be deployed, in which the leaves will be designed to move synchronously, increasing the voltage output, and therefore making the inherently lossy conversion process much more efficient thus opening up the possibility of making a practical device for this form of energy harvesting. Applications for such technology are widespread from military facilities to domestic gas flow meters. Despite extensive activity in the area of Energy Harvesting over the past several years, most studies concentrate on trial-and-error testing of certain configurations with little attention paid to thorough academic investigation of the systems behaviour. The aspen leaf type plate displays dynamic behaviour resembling the one known as the aeroelastic flutter of aircraft wing. Adaptation of existing knowledge to optimisation of the harvester will be the first step towards construction of an effective device. Overall, the programme aims at development of arrays of bio mimetic fluid elastic energy harvesters resembling a trembling aspen leaf. The proposed study is an early stage project of high academic significance. The research objectives are as follows. a. Experimentally study oscillations of an individual aspen leaf type flutter under various flow conditions and construct the corresponding mathematical model in the spirit of dynamical systems. Design a nonlinear harvester with a stable amplitude or frequency response over a broad range of ambient wind conditions. b. Connect individual harvesters into arrays and investigate both hydrodynamic and structural interaction between the elements in order to optimise the systems performance. The achieved degree of harvester synchronisation in an array will be related to needs and efficiency of piezoceramics based electricity generation.c. Validate developed models by wind tunnel tests when the system is exposed to both steady flow and grid turbulence. d. Results of the proposed experimental and modelling programme will be published to provide a basis for an EPSRC grant application. Simultaneously, commercial feasibility of deployment of harvesting arrays will be comprehensively considered.Select the research outcome from the themes: 1 - Energy 2 - Fluid Dynamics and Aerodynamics