AN EXPERIMENTAL INVESTIGATION OF CROSS-FLOW TURBINE EFFICIENCY

An experimental investigation was conducted to study the effect of som e geometric parameters on the efficiency of the cross-flow turbine. Tu rbine models were constructed with three different numbers of blades, three different angles of water entry to the runner, and three differe nt inner-to-outer diameter ratios. Nozzles were also constructed for t he experiments to match the three different angles of water entry to t he runner. A total of 27 runners were tested with the three nozzles. T he results of the experiments clearly indicated that efficiency increa sed with increase in the number of blades. Moreover, it was determined that an increase in the angle of attack beyond 24 deg does not improv e the maximum turbine efficiency. In addition, as a result of these ex periments, it was determined that for a 24 deg angle of attack 0.68 wa s the most efficient inner-to-outer diameter ratio, whereas for higher angles of attack the maximum efficiency decreases with an increase in the diameter ratio from 0.60 to 0.75.