To achieve high power plant efficiencies, the turbines in the plant must operate at the highest possible temperature. Present-day materials place a limit on these temperatures, so that cooling of the turbine blades is necessary to maintain their integrity in the face of the high temperature gases that pass through the turbine. One approach is to pass a coolant through flow passages situated within the blades. To further enhance the heat transfer within the passages, fins or ribs are used. The available information about the heat transfer characteristics of such finned or ribbed passages is insufficient for design. The experiments to be performed under the present proposal will remedy this deficiency. The heat transfer measurements will be supplemented by mass transfer measurements carried out by means of the naphthalene sublimation technique. The measured mass transfer coefficients will be converted to heat transfer coefficients via the analogy between the two processes. The obtained data will not only be useful for design but will also serve to verify numerical simulations.
