A review on silt erosion in hydro turbines

Erosive wear of hydro turbine runners is a complex phenomenon, which depends upon different parameters such as silt size, hardness and concentration, velocity of water, and base material properties. The efficiency of the turbine decreases with the increase in the erosive wear and final breakdown of hydro turbines. Various researchers have conducted experiments to study the effect of these parameters on erosive wear, but most of these experiments are on small-size samples in different types of test rigs to simulate the flow conditions in the turbine, but actual flow conditions and the phenomenon of erosive wear are too complex to simulate. In the present paper, studies undertaken in this field by several investigators have been discussed extensively. Based on literature survey various aspects related to silt erosion in hydro turbines, different causes for the declined performance and efficiency of the hydro turbines and suitable remedial measures suggested by various investigators have been discussed.