Fish Friendly Turbine

Speed variation means that the runner speed of the turbine is reduced with sinking discharge (part load). The hydraulic effect of speed variation and the efficiency are comparable to Kaplan turbines with pitchable runner blades. The runner blades of the DIVE-Turbines are fixed to the runner shaft.

Regulation of  Kaplan turbine and DIVE-Turbine: the runner speed of the Kaplan turbine is constant. The runner speed of the DIVE-Turbine is reduced in part load.

Regulation of  Kaplan turbine and DIVE-Turbine: the runner speed of the Kaplan turbine is constant. The runner speed of the DIVE-Turbine is reduced in part load – the runner blades remain opened. The collision risk is sinking with the reduced runner speed, while for the Kaplan turbine the collision risk is significantly rising in part load, as the blades are closing.

Mortality risk at full load and part load for Kaplan turbine and DIVE-Turbine: The mortality of the Kaplan turbine is rising significantly in part load, because the runner blades are closing. The mortality of the DIVE-Turbine is sinking in part load because the runner speed is reduced.  Due to the gap-free design of the DIVE-Turbine the mortality at full load is also assumed to be comparatively low.

The fish friendly behaviour of the DIVE-Turbine and specifically the positive effect of speed variation has been approved by practical research for fish length up to 25cm. More details on practical experiments  will be provided on request.