Heat transfer experimental investigation of mist/steam or steam within gas turbine blade internal cooling passage

Convective mist/air (steam) cooling is one of potential promising technology for advanced gas turbine blade cooling. It can greatly improve the cooling effectiveness of turbine blade using two-phase flow. Based on the experimental platform which was built to investigate the convection cooling of mist/steam two-phase flow within high temperature turbine blade cooling channels, the effect of Reynolds number, wall heat flux and mist mass flow rate on the temperature distribution and heat transfer coefficient of mist/steam cooled passage wall was studied. The thermal performance of steam and mist/steam was compared under the same conditions. The results show that the average Nusselt number of mist/steam, which is two-phase flow cooling fluid formed by injecting a small amount of fine water droplets into the main steam, is up to 3. 46 times the pure steam; When the cooling condition factor is less than 23, significant settlement and large droplets evaporate will be occurred in the central region of mist/steam cooled passage. Then the cooling effect of gas turbine blade internal cooling passage is significantly improved.