Effect of operating regime on water distribution in Pelton Bucket

In Pelton turbine, the jet of water strikes normal to bucket and spreads over the bucket in all directions. The distribution of water on bucket may be affected by operating regime of turbine which may affect the torque on runner. In the present work, the transient flow simulation of an existing 6 jets and 20 buckets Pelton turbine model is carried out to study the effect of operating regime on water distribution in buckets of Pelton turbine. The numerically predicted efficiency of turbine is compared with the experimental values at some critical operating point and found to be in close comparison. It is observed that water distribution is affected by speed and discharge coefficient. The maximum water flows axially at all runner speed coefficient and it has parabolic variation with the highest value at rated speed. The flow in radial direction is very less as compared to axial flow. As the discharge increases, water volume fraction found to be more at all locations of the bucket and maximum water volume fraction is seen at mid spans for all discharge values.