Impact of Blade Quality on Maximum Efficiency of Low Head Hydraulic Turbine

Paper presents considerations based on 1D Euler equation for hydraulic turbine stage efficiency with the help of Energy–Losses diagram. It has been shown that the character of rotor blading strongly depends on the ratio of guide blade losses to rotor blade losses. This is the crucial point of presented analysis. The presented method gives the information what has to be done in order to achieve maximum stage efficiency for designed profiles. The problem how profiles should be shaped is left to either experience or to higher order computation for the details of profile characteristics. It has to be emphasized that flow deflection angle and losses are coupled and they have to be matched according to presented results. Presented approach based on 1D model has to be correlated with results obtained from higher order models like 2D or 3D. These higher order models, giving more details of flow through the turbine stage, are not suitable for the prediction of turbine kinematics to assure maximum efficiency for given by investors input data of designed turbine stage.