Irrigation and Power Research Institute, Punjab, Amritsar
In high head, multi-purpose, storage reservoirs, conduits are located at two or more lake levels and a dual control with an emergency gate and a service gate, for regulating the outflow, is employed. The high velocity flow particularly in part-gate openings under high heads leads to very serious problem of cavitation. In this paper the possible methods for the elimination of low-pressures have been discussed. It has been established that the conventional tertical installation of Jet Flow Gate immediately downstream the dam face in conjunction with an air venting system comprising of two 24 in. (0.61 m.) (P) pipes distributing air over an angle of 180° eliminates the negative pressures. The maximum velocity [129.35 ft. (39.42 m.)/sec. (m)] of air draw is well below the critical limit and hence the arrangement is considered suitable for adoption in engineering practice.
