On the optimal design of the form of hydroturbine impeller blades

When designing a hydraulic turbine, a machine of better performance characteristics and primarily of the highest possible efficiency should be created. In the process, a designer is given a numer of restrictions concerning dam height, impeller diameter, etc. The turbine efficiency can be increased by varying the impeller blade profile or the angular velocity of the impeller rotation and by some other design techniques.The problem of optimization of hydroturbine parameters has been investigated in a number of works (see e.g. Fedorov 1983, 1984; Klimovich and Fedorov 1984; Kazachkov and Provad 1989). This paper presents some optimum decisions obtained for one-and two-dimensional axisymmetrical flow models. The turbine efficiency and local cavitation coefficients are accepted as the goal functionals. Necessary optimizing conditions are described, and calculated optimum characteristics of blade systems are given.