Liquid-cooled, turbine bucket with enhanced heat transfer performance

摘要

Individual coolant passages in the airfoil portion of a liquid-cooled turbine bucket are provided with means whereby the main flow of liquid coolant moving in each such individual passage during turbine operation under the influence of centrifugal force is split into a pair of flows with each sub-flow moving along a generally helical path. Also, the splitting means is provided with means to interrupt each sub-flow so as to enlarge significantly the internal wall area of such coolant passage with which the liquid coolant makes contact. In the embodiment described the splitting means is a twisted tape member bonded along its edges within a tubular coolant passage and the interrupting means are a series of inwardly-directed slots in the edges of the tape.