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Effect of temperature, suction head and flow velocity on cavitation in a Francis turbine of small hydro power plant

Gohil, Pankaj P., Saini, R.P.
Energy 2015 v.93 pp. 613-624
atmospheric pressure, models, power plants, temperature, turbines, water power
Erosion due to cavitation in hydro turbines is one of the reasons for component failure that costs a lot to the hydro power plants. Inception and development of cavitation depend upon different parameters such as atmospheric pressure, suction head, velocity of flow, temperature, gas content in the liquid and operating hours of the turbine. Parameters generally considered for design of a turbine and are used to predict cavitation could be different at actual site. The cavitation in hydro turbine is predicted during model testing and correlated with specific speed. However the erosion and efficiency decay due to cavitation phenomena of turbines are too complex to stimulate which depends on other operating conditions at site.Under the present study, an attempt has been made to carry out a numerical analysis to investigate the effect of temperature, suction head and flow velocity on cavitation in a Francis turbine by using CFX code. The experimental investigation has been carried out to validate the numerical method by visualization technique. Using numerical data obtained during analysis for different considered parameters, correlations are developed for efficiency loss and cavitation rate in Francis turbine as a function of these parameters i.e., temperature, suction head and flow velocity.