Abstract: An experiment is performed on a facility with 180° turnover variable cross-section channel with ribs which is built based on the inner structure of the real turbine blade of an aero-engine. Heat transfer characteristics for the upper and lower surfaces with 60° parallel or crossed ribs are investigated. The results show that Nu number for the channel increases with Re number. The two rib configurations give similar heat transfer characteristics at low Re number and the interleaving rib configuration shows better characteristics than the parallel rib one at high Re number. The distribution of wall temperature is not consistent with the periodic arrangement of the ribs. The stream wise wall temperature gradient for the crossed rib one is lower than that for the parallel rib one.

Key words: gas turbine, cooling blade, heat transfer test, variable cross-section, turnover channel