Author(s): P. Rutschmann; S. Schafer; B. Rutschmann; F. Geiger
Keywords: No keywords
Abstract: Over the last three years, tests with almost 2000 fishes have been conducted at the patented TUM Hydro Shaft Powerplant involving five different species, namely trouts, graylings, barbels, bullheads and minnows with fish sizes between 50 and 200 mm. The turbine mortality very much differed among the tested fish species, and a large variation is detected over the various test runs. Amazingly the worst swimmer, the bullhead, showed the lowest probability of damage or injury in the turbine. However, this contribution analyses the results species independently and shows that probabilities of mortality or injury for given bar clearance depend on the intake flow velocity, the operation of the turbine and the fish length. The present paper discusses the various influences of the hydraulic conditions at the trash rack and the operational setup of the turbine on mortalities and tries to quantify these effects. Also the paper separates the size dependent probability of trash rack passage from that of pure turbine damage and thus allows to derive total downstream passage survival rates for the Shaft Powerplant.