Author(s): S Fraas; A Tismer; S Riedelbauch

Linked Author(s):

Keywords: Axial turbine; Runner blade optimization; Multidisciplinary optimization; Cavitation; Structural mechanics

Abstract: The results of three optimization runs of an axial turbine’s runner blade are compared with each other. In the first optimization run, only the efficiency is optimized. In the second run the minimization of the cavitation volume is added as an objective, while in the third run, additionally, structural mechanical aspects are taken into account. Three operating points are simulated during the optimization process. The results of the first two runs show an increased efficiency at full load and a decreased efficiency at part load if cavitation volume is minimized. Taking structural mechanics stress limits into account the efficiency at all operating points is reduced, especially at part load. Furthermore, the cavitation volume tends to increase at full load. Nevertheless, the permissible stress is not maintained by any of the best individuals of the optimization runs without taking into account structural mechanics stress limits. This points out the importance of simultaneously considering both structural as well as fluid mechanical aspects in the optimization process of a hydraulic machine.

DOI: https://doi.org/10.1088/1755-1315/1483/1/012004

Year: 2023