Experimental study of pressure drop and heat transfer in a U bend channel with various guide vanes and ribs

An experimental study was conducted to investigate pressure drop and heat transfer in a U-bend section with various configurations of guide vanes and two kinds of rib shapes on the outer wall. Ten guide vane types were tested. Results highlight that the use of special guide vanes can reduce the pressure drop penalty up to a maximum of 31%. However, guide vanes are usually associated with heat transfer reduction. To further enhance heat transfer, transverse and V-shaped ribs were attached on the outer wall. Thermal performance evaluation showed that the 45 degrees V-shaped downstream-pointing ribs coupled with guide vane configuration 5 give the best thermal performance. The results of this study can be employed to improve the internal design of modern gas turbine blade cooling systems.