OPTIMIZATION WORKS FOR IRRIGATION BY THE HOWELL-BUNGER VALVES

Abstract

In Bahcelik Dam, irrigation and drinking water is discharged from the bottom outlet to diversion channel when the reservoir water surface elevation is between1472 m-1500 m. It is planned that the flow discharge will be controlled by the valves automatically depending on the water demand. In this system; the valve type is characterized by opening, closing and regulating time of the valves for controlling system placed at the downstream of the main diversion channel. Howell-Bunger valves which are cavitation and water hammer resistant, velocity limitless, electronically controllable water control systems are selected. In the experimental study, four Howell-Bunger valves each having D=1400 mm and maximum discharge capacities Q=8.5 m3/s were placed at the upstream part of the main diversion channel and tested in various valve openings to obtain optimum operating conditions for all reservoir water levels in a 1/10 scaled model. It is found that, as the reservoir elevation is getting high, valve performance increases up to 75% of valve opening. In spite of the expected discharge capacity is 8.5 m3/s from a valve which woks in 100% open condition, this value is reached with two valves which work in 100% opening at the minimum reservoir operation level, i.e. H=1472 m.