Analysis of cooling solutions in a gas turbine blade by means of CHT CFD

In a modern gas turbine, up to about 20% of the main compressor flow is bled off to perform cooling and sealing of hot-section components. As the energy demand increased, the technology behind the gas turbine cooling system has developed, adopting new designs to enhance the performance of the machine. This work focuses on the analysis of rib-turbulated cooling channels, adopted in the first row blades of an industrial gas turbine engine. Rib-turbulated cooling channels paved their way in the last decades to substitute smooth channels. The implementation of turbulators has the main effect to enhance the heat transfer between the cooling fluid and the blade material. On the other hand, the pressure losses increase, corresponding to an increased pumping power to let the cooling air flow. The simulations were performed through a commercial software namely STAR CCM+. The study has been mainly devoted to the comparison of three different configurations: standard smooth channels and 2 turbulated geometries. The three different geometries were compared both in terms of fluid-dynamic and thermal performance. It was found that, by adopting turbulated channels, an increase in the heat transfer coefficient is achieved. Halving the coolant mass flow rate comes at a price of a penalization of the heat flux of 25%.