Analytical Prediction of the Jet Force in Pelton Turbine

Energy generation through hydropower has become increasingly important in our quest for clean, renewable energy. The turbines in the hydropower have to endure harsh working conditions due to the frequent starts and stops to meet the current grid demands and are thus susceptible to structural damage under the action of hydraulic forces. The dynamic response due to these hydraulic forces can create unwanted mechanical vibrations in the system. Pelton Turbines are subjected to strong dynamic forces whenever it is impinged by the jet of water. It is of utmost importance that we avoid the resonance condition when the force due to the jet of water strikes the Pelton buckets. So, the analytical prediction of the jet force of the Pelton turbine is a vital issue. The Pelton buckets are assumed to be rectangular with negligible thickness and the jet of water is assumed to strike centrally on the bucket. The area of the impinging jet is parametrized with the height of the jet. The normal forces acting on the system and buckets are calculated for different bucket positions and the system forces are resolved in the transverse directions. The periodic forces that were obtained were converted into harmonic forces using Fourier series to be used for Forced vibration analysis.