【作者】 李应龙；

【导师】 欧阳华；

【作者基本信息】 上海交通大学 ， 航空宇航推进理论与工程， 2010， 硕士

【摘要】 风能作为一种取之不尽、用之不竭的新型能源具有良好的应用前景和开发潜力。随着风力机的广泛应用和当今世界人口数量的膨胀,大型风电场周围已不可避免地有很邻近的居民区;而现代大型风力机为提高其经济性,在不断提高风轮叶尖速比的同时,也相应地产生了噪声增加的后果,因而在人类环境保护意识增强的今天,对风力机噪声的研究变得越来越急迫与重要。风力机噪声主要分为机械噪声和气动噪声。目前已可通过多种工程手段大大减小风力机的机械噪声,但风力机的气动噪声依然是个难以解决的问题。预测风力机发出的气动噪声,是风力机设计时的重要步骤。目前预测风力机气动噪声的方法大致可分为两种。一种是使用CFD方法求解,但目前这种方法比较复杂,而且还不是很成熟。另一种方法是使用基于半经验公式的预测模型,这种方法也是最常用的,它在计算速度和计算精度上是比较好的折衷。本文的主要工作如下:1.使用基于半经验公式的Brooks, Pope, and Marcolini翼型自噪声预测模型和Lowson湍动来流噪声预测模型,编写水平轴风力机气动噪声预测程序。使用编制的程序,预测给定风力机在给定工况下的噪声,并与实验值进行比较,预测结果与实验结果符合良好。2.分析了湍流强度、安装角等因素对风力机气动噪声的影响,提出有效预测和减小风力机气动噪声的措施。3.在预测模型中采用Du-Selig静态失速延迟模型来修正两维失速问题,尝试提高该模型的预测准确度,但结果表明静态失速延迟模型对风力机气动噪声预测模型计算结果的影响较小,可以忽略。更多还原

【Abstract】 The development of wind energy in the world is flourishing because it is a kind of absolutely clean and renewable energy. But with the fast increase of wind energy development, it also gives rise to the problems concerning public acceptance of wind energy. The noise is the main drawback. The noise from wind turbines may annoy people who live around. This problem becomes especially serious due to the fact that wind turbines are densely covered in many areas. Therefore it’s necessary to estimate the noise level in the field where the wind turbines are installed.Generally, the noise from wind turbine is composed with mechanical noise and aerodynamic noise. The mechanical noise is caused by the different operating machine elements which can be reduced efficiently by many engineering methods. However, the way to reduce aerodynamic noise from wind turbines is a bit complex which should be studied more. Through the years, several models have been proposed to explain and predict wind turbine noise.Some of the models make use of complex CFD solvers that have not yet matured to be applied in practice. As a compromise between computing speed and accuracy, the most commonly used models are based on semi-empirical relations.Main contents of this thesis are described as the following:1. Employ the experimental results on airfoil self-noise by Brooks, Pope and Marcolini, together with the turbulence inflow model proposed by Lowson. The model was tested successfully against the measurement result.2. Analyze the effect of turbulence intensity and pitch angle on sound pressure level of wind turbine aerodynamic noise and present effective methods of predicting and reducing wind turbine aerodynamic noise.3. Du-Selig stall delay model is used to improve the performance prediction accuracy. But the calculation results have shown the stall delay model have little effect on the prediction accuracy.更多还原