Computational study of gas turbine blade leading edge internal cooling using efficient heat transfer surfaces

Gas turbine blades are one of the most critical components due to their exposure to high thermal and centrifugal loads. Today studies in this field are concentrated on the improvement of gas turbine performances in terms of higher power output. In the present numerical study, flow and heat transfer characteristics of 3-D triangular vortex generators (VGs) located in a triangular duct representing internal cooling channel of a gas turbine blade are investigated deeply to find the best VG type and the best streamwise and spanwise distances between the VGs and the duct base in the context of thermal and hydrodynamic properties. The investigated VG types are periodically located inside the triangular duct in either smooth or in alternating directions and they are oriented as CFU-CFU, CFD-CFD, CFU-CFD and CFD-CFU configurations. The flow Reynolds number is fixed to 20,000, and inlet and wall temperatures are fixed to 20°C and 1760°C, respectively. The rotation number is 0.488. According to the present numerical results, it is found that the best cooling performance for the leading edge of the gas turbine blades is obtained for the CFD-CFU configuration and for the streamwise distance between the VGs is equal to the 0.5 times to the VG length and the best spanwise distance between the VGs and the duct base is equal to 0.0222 and0.222 times the VG length, for the CFD and CFU configurations, respectively.