Effect of Mist Size on the Cooling Performance for Internal Cooling of Gas Turbine Blade

Efficient cooling structures and coolant materials are essential factors in improving turbine efficiency and prolonging their service life. It is imperative to develop advanced cooling technologies that augment the durability of the hot components in gas turbines. This study primarily investigates the effects of two-phase flow (mist/steam) and the mist particle size on secondary flow distribution and heat transfer within a cooling channel. The simulation result indicates that secondary flows benefit from synergistic effects when mist is introduced into the cooling channels, leading to increased velocity magnitudes. Notably, smaller mist sizes are more effective in enhancing both the secondary flow and heat transfer performance due to their evaporation characteristics under the given heat flow conditions. Furthermore, when considering the Nu/Nu0 factors, there's an improvement of 26.79% at mist/steam mass ratios of 10% with a mist size of 10 μm. Hence, a mist size of 10 μm emerges as the optimal condition for evaporation within the channel across various mist/steam mass ratios, suggesting that the peak heat transfer and cooling efficiency can be realized at this size.