Effect of Longitudinal Vortex Generator on Impingement Cooling over Leading Edge of a Gas Turbine Blade

The flow and heat transfer on leading edge of a gas turbine blade were investigated by using 3-D numerical method. A pair of delta-winglet vortex generators (VGP) was installed in the jet cavity to study the effects of following factors on the impingement heat transfer, such as the attack angle of VGP, the spacing between two VGPs and the distance between the VGP and the jet nozzle. In addition, the mechanism of heat transfer enhancement by longitudinal vortex generator was discussed in detail. Results show that the cross flow velocity in front of the jet nozzle decreases in case the delta-winglet VGP is placed on the top wall, when both the jet penetration and the turbulent kinetic energy improve accordingly in the jet cavity, resulting in significantly increased peak value of heat transfer and enlarged area of heat transfer region. However, the effects of VGP geometry parameters on the heat transfer are not significant at a lower cross-flow Reynolds number.