Investigations on Deformation in Discharge ring and Outer Distributor Cone Performance in Small Hydro Power Plants with Cavitation

Small Hydroelectric Power (SHP) development is increasingly undertaken all over the world, especially in the developing countries, because of their various merits, varied application, Small hydro is its comparatively shorter period of two to three years as against five to seven years for major hydropower projects. In the context of gestation period, it would be relevant to mention that the technological innovations and improvement cut down the commissioning time of this small hydro. In many of the developing countries, more attention is being paid to the development of small hydropower generation. Due to the crisis caused by high rise in costs of fossil fuels together with increased awareness towards environmental impact of large projects leads to thrust of small hydro. In hydroelectric power plants the water hammer is a very important problem, The abrupt increase of pressure, which is caused by a rapid closure of the guide vanes in hydro power plants, creates water hammer. where the flow of water is rapidly varied in accordance with the change of load on turbines. Small hydropower schemes with higher discharges are frequently associated with severe pressure variations due to the relatively small machine inertia compared to the large water column inertia. Any flow change either caused by normal or abnormal situations influences the hydrodynamic response and consequently the stability and efficiency of the hydro turbines.