Selection of Erosive Wear Rate Parameters of Pelton Turbine Buckets using PSI and TOPSIS Techniques

Hydro turbine machineries erosion due to silt is a complex issue for the effective practice of hydropower plants. Erosion caused by silt of the Pelton turbine buckets is a compound phenomenon that depends on size of silt particles , silt particles concentration , velocity of jet , and working time . This paper deals with the influence of silt erosion for various silt loaded factors and effective parameters. The preference selection index (PSI) and technique for order of preference by similarity to ideal solution (TOPSIS) approaches has been adopted to find optimal set of parameters which offers the highest performance for the Pelton turbine. Based up on the results obtained from both PSI and TOPSIS approaches it is found that optimal performance has been provided by A-1 alternate with geometric and flow parameters as , , and respectively

Alternative Design of Double-Suction Centrifugal Pump to Reduce the Effects of Silt Erosion

Large amounts of sediment in the Himalayan rivers causes severe silt erosion to the hydraulic machinery operating along these rivers. In this study, the effects of silt characteristics on the silt-erosion characteristics of a double-suction centrifugal pump was studied and the anti-erosion property of bionic convex domes on silt erosion under these conditions was explored by using computational-fluid-dynamics methods, partly supported by a painted-blade erosion experiment. The results show that the silt size affects the erosion position and erosion strength, whereas the silt concentration mainly affects the erosion strength for the studied range. The bionic convex domes provide an effective solution to improve the silt erosion for most of the investigated silt-laden conditions by decreasing the erosion rate and the erosion area of the blade. The anti-erosion mechanism was studied combined with large eddy simulation. The analysis shows that the relative velocity of water around the blade surface is changed and the mass flow rate of silt particles hitting the blade is reduced by inducing swirling flows around the bionic convex domes.