Effect of Orifice Jet Configuration on Heat Transfer in a Channel with Inclined Target Surface Cooled by Single Array of Impinging Jets with Outflow in Both Directions

摘要

An experimental study has been carried out to study the effect of origice-jet plate configuration on heat transfer behavior in a channel with inclined heated target plate cooled by single array of equally spaced impinging jets. Air ejected from an array of orifices is impinges on the heated target surface. The target plate forms the leading edge of a gas turbine blade. The study includes the effect of various orifice-jet plate configurations, feed channel aspect ratios (5 ≤ H/d ≤ 9) and Reynolds number (9300 ≤ Re ≤ 18800) on the heat transfer characteristics for a given outflow orientation (outflow passing out in both the directions). Three orifice-jet plate configurations (centered, staggered, and tangential holes) have been examined. It has been noticed that Nusselt number (Nu) is high for higher aspect ratios. For a given plate-1 with single array of equally spaced centered jets and for Re = 18800 (outflow passing out in both directions), the local Nu for H/d=9 has been found to be greater than Nu of H/d=7 by 5%. The percentage increase in average Nu has been found to be about 11% with centered holes as compared staggered orifice-jet plate. The percentage increase in average Nu has been found to be about 11% with staggered jet-plate as compared to tangential orifice-jet plate configuration.