Investigation of the effects of realistic non-homogenous turbulence on structural loading and the performance of tidal energy devices

与风力涡轮机所经历的密度较小、速度较高和无边界流中的湍流不同，潮汐流发电机的结构载荷和性能受到操作环境中的湍流特性的影响更大。虽然潮汐站点的平均流量特性已被充分理解，并且可以有一定的信心进行建模，但相对缺乏有关湍流特性的知识。尽管目前正在开发和实施一系列潮汐流发电机（TSG），但是湍流影响的这种不确定性通过可靠性和性能的不准确预测而阻碍了进展，从而阻碍了经济可行性，并且通常导致非常保守的设计方法，其固有地实施起来更昂贵。尽管谨慎的设计，湍流已被确定为一个可能的原因，在组件故障发生在业务单位。在过去的几年里，随着几篇论文的发表和Partrac最近完成的几个潜在地点的实地研究，潜在潮流地点的湍流特性越来越受到关注-其结果不在公共领域。尽管这一重点，几篇论文专门研究潮汐蒸汽发生器的湍流的影响是在文献中，没有被发现的影响湍流特性是空间可变的横截面积的device.This项目的建议后形成的讨论博士Venugopal和将与目前正在进行的EPSRC资助FloWTurbb项目。潮汐站点的测量数据将用于开发一个计算模型，并使用计算流体动力学软件实现潮汐通道流中真实的非均匀湍流。然后，该模型将用于研究其对潮汐流发电机的结构载荷（特别是疲劳载荷）的影响，并有可能对目前正在实施的实际设备和/或组件进行建模。然后，模型的复杂性可以扩展到包括波浪载荷，进一步的工作调查对单个发电机和阵列性能的影响是可能的。将通过规模实验室测试寻求结果的实验验证，最好将FloWave设施与FloWTurbb项目结合使用。这项工作的一个组成部分将包括调查的方法，调节流在实验设施，以密切配合所需的湍流特性，在一个可靠的和可控的方式。这方面的开发工作可以使用工程学院内的小水槽进行。该项目的结果将最终用于提供更有效的设计方面的湍流特性在实际潮汐流网站的建议。

Unlike turbulence in the less dense, higher velocity and unbounded flow experienced by wind turbines, structural loading and the performance of tidal stream generators is more heavily influenced by the turbulent characteristics of flow in the operating environment. Whilst the characteristics of mean flow at tidal sites are well understood and can be modelled with some confidence, there is a comparative lack of knowledge regarding turbulence characteristics. Although a range of tidal stream generators (TSG's) are currently being developed and implemented, this lack of certainty in the effects of turbulence serves to hinder progress through less accurate prediction of reliability and performance, thus economic viability, and generally results in very conservative design approaches which are inherently more expensive to implement. Despite cautious design, turbulence has been identified as a possible cause in component failures that have occurred in operational units. Characterisation of turbulence at potential tidal stream sites has gained increasing focus in the last few years with several papers being published and a field study at several potential sites recently having been completed by Partrac - the results of which are not in the public domain. Despite this focus, few papers specifically investigating the effects of turbulence on tidal steam generators are available in the literature and none have been found regarding the effects turbulence characteristics that are spatially variable over the cross sectional area of the device.This project proposal was formed after discussion with Dr Venugopal and will be associated with the currently ongoing EPSRC funded FloWTurb project. Measurement data from tidal sites will be used to develop a computational model, implemented with CFD software, of realistic non-homogeneous turbulence in tidal channel flow. This model will then be used to investigate its effects on the structural loading (particularly fatigue loading) of tidal stream generators with the possibility to model actual devices and/or components currently being implemented. The complexity of the model may then be extended to include wave loading, with further work investigating effects on performance of both single individual generators and arrays a possibility. Experimental validation of results will be sought via scale laboratory testing, preferably using the FloWave facility in conjunction with the FloWTurb project. A component part of this work will include investigation of methods for conditioning flow in the experimental facility to closely match desired turbulence characteristics in a reliable and controlled fashion. Development work for this can be undertaken using the small flume available within the School of Engineering. The results of the project will ultimately be used to provide recommendations for more effective design with regards to turbulent flow characteristics at actual tidal stream sites.