Unsteady gust response of tidal stream turbines
Unsteady gust response of tidal stream turbines
复制标题
潮汐流涡轮机的不稳定阵风响应
作者：
Carl L. Sequeira;R. Miller
本文研究了二维线性非定常翼型理论用于模拟潮流水轮机非定常阵风响应的局限性。这项工作的动机是这样一个事实，即需要准确的非定常负荷预测，以确定涡轮机的寿命。目前工业上最先进的设计规范使用基于Theodorsen理论的单一模型来预测对所有类型阵风的响应。本文表明，不同类型的阵风需要不同类型的模型。涡阵风，如由于湍流和剪切流，应使用西尔斯和霍洛克的理论相结合的模型。压力阵风，如自由表面波引起的阵风，应使用洛伊理论进行建模。这些模型的准确性进行检查，使用数值预测。结果表明，对于有压阵风，采用Theodorsen理论对非定常升力幅值的预报误差接近18%。通过使用Loewy理论的校准版本，该最大误差可以减小到小于8%。同样，使用Sears/Horlock组合理论可以将高频涡旋阵风响应的预测误差从18%减少到近10%。阵风的范围可能发生在真实的潮汐网站也检查。这表明，在最有可能的情况下，压力阵风会导致负载变化，可以准稳定地建模，但漩涡阵风必须使用组合西尔斯/霍洛克理论建模。
This paper investigates the limitations of 2D linear unsteady aerofoil theory for modelling the unsteady gust response of tidal stream turbines. The work is motivated by the fact that accurate unsteady load prediction is required to determine turbine life. Current state of the art design codes in industry use a single model, based on Theodorsen's theory, to predict the response to all types of gust. This paper shows that different types of gust require different types of model. Vortical gusts, such as due to turbulence and shear flows, should be modelled using a combination of Sears' and Horlock's theories. Pressure gusts, such as those caused by free surface waves, should be modelled using Loewy's theory. The accuracy of these models is examined using numerical predictions. It is shown that, for pressure gusts, using Theodorsen's theory can cause errors in prediction of the unsteady lift amplitude by nearly 18%. By using a calibrated version of Loewy's theory this maximum error can be reduced to less than 8%. Similarly, using the combined Sears/Horlock theory can reduce the error in predicting the response of high frequency vortical gusts from 18% to nearly 10%. The range of gusts likely to occur at real tidal sites is also examined. This has suggested that, in most likely situations, pressure gusts cause variations in loads which can be modelled quasi-steadily, but vortical gusts must be modelled using the combined Sears/Horlock theory.
影响因子：
5
作者：
I. Milne;A. Day;Rajnish N. Sharma;R. Flay
通讯作者：
I. Milne;A. Day;Rajnish N. Sharma;R. Flay