Conjugate heat transfer analysis of a rotating ribbed gas turbine blade–vane system

Cooling of modern gas turbine blades and vanes is crucial, as they are exposed to extremely high temperatures. The present investigation makes a three-dimensional conjugate heat transfer analysis of internal convection of a ribbed gas turbine vane–blade system under rotational conditions. Simulations have been performed for a single turbine stage, including stationary vanes and rotating blades. The performance of rib-roughened coolant channels is compared to that of smooth channels for different conditions. Flow turbulence is resolved using the Shear Stress Transport (SST k–ω) model with automatic wall function. The compressibility effects in the external hot-gas flow and the rotational effect-induced complex flow patterns inside the rib-roughened coolant channels have been analyzed. The Coriolis force, caused by the rotation of blades, affects the internal flow structures within the smooth and ribbed coolant channels. Ribbed channels significantly enhance local heat transfer by disrupting Coriolis-induced vortex structures and promoting secondary flow. The flow and heat transfer characteristics within coolant channels vary at different blade positions. A transition from supersonic flow at the leading edge to the transonic flow at the trailing edge of the suction side of rotor blades is observed. Compared to the smooth channels, the ribbed channels achieve a blade temperature reduction of up to 191.8 K and a 49.9% increase in the Nusselt number, with a moderate pressure penalty. The study highlights the critical role of rib geometry and rotational effects in optimizing the internal cooling performance of turbine blades for high-temperature applications.