Effect of surface roughness on losses and performance of Kaplan turbines

Even marginal improvements in the efficiency of powerful modern hydro turbines can yield substantial technical and commercial gains in term of energy conservation and increased revenue. To improve the performance of such efficient turbines, it is necessary to study the nature of losses in depth and to find a means of reducing them. This paper describes analytical procedures with practical data and provides a reasonably simple computational method to obtain realistic estimates for roughness effects on the optimum efficiency of Kaplan turbines.