Numerical investigation on cooling performance of pulsating flow in a ribbed channel

The gas turbine vanes have to withstand the impact of the high temperature gas and keep working in this high temperature which is much higher than the metal melting point. For this reason, these vanes need effective cooling. The traditional coolant is the steady state air flow, whose cooling performance is not satisfied to some extent. The pulsating flow may have better cooling performance due to its more complicated flow characteristics. This paper performs a numerical study to investigate the cooling performance of pulsating flow for the internal convection cooling of the vane. The geometric model is a heated rectangular duct with rib turbulators cast on its internal surfaces. This rectangular duct has different geometric parameters such as different rib spacing (P/e) and channel width to height ratio (W/H). Also, the coolant pulsating flow has three different flow patterns (triangular wave, square wave and sinusoidal wave). Studies show that the pulsating frequence (fv), pulsating amplitude (A) and Reynolds number (Re) are the most immediate parameters characterizing the flow and heat transfer of the pulsating flow. The numerical results of the pulsating flow have been analyzed and compared with the steady flow.