Form-Induced Hydraulic Forces on Three-Leaf Intake Gates

Studies were conducted on the 3-leaf gates for the powerhouse intake for TVA’s Melton Hill Dam to develop a design that would effectively shut off the turbine flow for all intake discharges up to the runaway turbine condition. The intake conduit is a closed, converging rectangular section approximately 18 ft wide by 40 ft high at the gate section, located 13 ft downstream from the entrance. Tests on five proposed gate lip shapes and on nine other basic shapes failed to produce a satisfactory design because of excessively large hydraulic forces induced by the lip forms, oscillation of the gate during closure, and, in several of the designs, failure of the leaves to close. Combinations of lip forms resulted in an acceptable design.