Discussion on Papers 9–12

Mr. J. P. Taulan, Societe Neyrpic

At heads lower than nominal, the fixed blade

turbine has a discharge greater than that at maximum power output for a double regulated machine, and consequently operates in a very bad zone with too high flow velocities, and the angle of attack is not adapted to the blade profile, resulting in severe vibration and

cavitation.

By decreasing the blade angle and allowing lower discharge, it would be possible to increase the turbine power output and -obtain better efficiency without energy losses through vibration

(which is bad for the overall machine life) and without cavitation which must be eliminated in sea water conditions.