A study of irregularity of reaction in Francis turbines

Irregularity of reaction in hydraulic machinery causing vibration has up to the last few years been of relatively little importance and treated as a more or less necessary evil. With the advent of larger units, particularly for high heads, it became of prime importance that there be little or no vibration. In cases where vibration occurred, a cut and try system of remedying it was usually resorted to and as little publicity as possible given the procedure. For the study of such phenomena as vibration caused by irregularity of reaction manifesting itself in several impulses per second the electrical methods long since developed are admirably adapted and this paper gives a brief description of a successful method of study.