Effects of Non-homogeneously Distributed Roughness on Turbulent Pipe Flow

该建议解决了一个对水力发电行业至关重要的问题：首次提供非均匀分布粗糙度元件的压降数据。这些数据很重要，因为目前管道中粗糙度元素的数据仅限于均匀的沙粒型粗糙度或均匀但稀疏分布在表面上的粗糙度。魁北克水电公司注意到，在他们的许多水力压力管运行中，在超过30年的时间范围内，形成了非均匀间隔和非均匀分布的粗糙度元素，导致水头（压力）下降，从而导致发电量降低，并伴随数百万美元的收入损失。该项目将支持1名硕士的培训。他们将进行一组仔细的实验来量化这些损失，并得出描述非均匀粗糙度对表面摩擦（压力损失）影响的相关性，从而使魁北克水电公司能够更好地评估何时进行压力管清洗。生成的数据将填补我们对非均匀间隔和非均匀分布粗糙度元素影响的知识的明显空白。这些数据对科学界来说将是新的，并将产生大量的档案出版物。这些数据虽然对魁北克水电公司至关重要，但将通过科学文献传达给加拿大的其他水力发电机，从而有助于提高加拿大的整体水力发电效率，并为安排压力管道维护提供关键信息，以实现最大的成本效益。

This proposal addresses a problem of critical importance to the hydroelectric power industry: to provide for the first time pressure drop data for non-homogeneously distributed roughness elements. These data are important as current data for roughness elements in pipes are restricted to uniform sand-grain type roughness or for roughness that is uniformly but sparsely distributed on a surface. Hydro Quebec have noted that in many of their hydro-electric penstock operations, that over a thirty year time frame, non-uniformly spaced and non-homogeneously distributed roughness elements are formed that gives rise to a drop in head (pressure) that translates into lowered electricity production with the concomitant loss of millions of dollars in revenue. This project will support the training of one M.A.Sc. student over two years and one Ph.D. student over four years, who will carry out a careful set of experiments to quantify these losses and to derive correlations that describe the effects of non-uniform roughness on skin friction (pressure loss) from which Hydro Quebec will then be in a better position to assess when to perform penstock cleaning. The data generated will fill a glaring gap in our knowledge on the effects of non-uniformly spaced and non-homogeneously distributed roughness elements. These data will be new to the scientific community and will generate numerous archival publications. These data, while of critical importance to Hydro Quebec will be communicated to other hydro-electricity generators in Canada through the scientific literature, and thereby will help improve Canada's overall hydro-electricity production efficiency as well as to provide critical information for scheduling penstock maintenance to achieve maximum benefit-to-cost.