Yuji Nakanishi

Numerical Simulation of the Flow in a Pelton Bucket by a Particle Method : 1st Report, Flow in a Rotating Bucket Using Relative Jet Paths(Fluids Engineering)

The flow in a rotating Pelton bucket is simulated by a Moving-Particle Semi-Implicit Method (MPS). In the MPS method, the solid wall of the bucket has to be represented by the same calculation particles as those for fluid, though a Pelton bucket has complicated 3D shape. Therefore, a simple method arranging the wall particles is introduced. As the first step of MPS simulation, the jet entering the bucket is determined by relative jet paths. The free sheet flow on the rotating bucket is simulated and discharging flow pattern is compared with the photograph taken in the model test.

Scale Effect of Jet Interference in Multinozzle Pelton Turbines

The IEC model acceptance test code stipulates that there is no scale effect in Pelton turbines[1]. One of the primary reasons why the scale effect in Pelton turbines is ignored, so far, is that the complicated unsteady free water-sheet flow on Pelton buckets prevents to numerically analyze the loss mechanism. Another reason is that the positive scale effect in the closed conduit flow from the turbine inlet to the nozzle outlet tends to compensate for the negative scale effect in free water-sheet flow on the buckets.