Gas turbine plays a significant role throughout the industrial world. Aircraft propulsion, land-based power generation, and marine propulsion are most notable sectors where gas turbines are extensively used. The power output in these applications can be increased by raising the temperature of the gas entering the turbines. Turbine blades and vanes constrain the temperature of hot gases. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream are based on increasing heat transfer areas and the promotion of turbulence of the cooling flow. Heat transfer is enhanced for example due to ribs, bends, rotation and buoyancy effects; all characterizes flow within the channels. Computational Fluid Dynamics (CFD) simulations are carried out using turbulence models like Large Eddy Simulation (LES) and Reynolds stress model (RSM). These CFD simulations were based on advanced computing technology to improve the accuracy of three-dimensional metal temperature prediction that can be applied routinely in the design stage of turbine cooled vanes and blades. The present work is done to study the effect of secondary flow due to the presence of ribs on heat transfer. In this paper, it is obtained by casting repeated continuous V and broken V-shaped ribs on one side of the two passes square channel into the core of blade. Two different combinations of 60° V and Broken 60° V-ribs in the channel are considered. This work is an attempt to collect information about Nusselt number inside the ribbed duct. Large Eddy Simulation (LES) is carried out on the Inlet V and Inverted V outlet continuous and Broken Inlet V and Inverted V-rib arrangements to analyze the flow pattern inside the channel. Hybrid LES/Reynolds Averaged Navier-Strokes (RANS) modeling is used to modify Reynolds stresses using Algebraic Stress Model (ASM), and a CFD strategy is proposed to predict heat transfer across the cooling channel.
A physical-space version of the stretched-vortex subgrid-stress model for large-eddy simulation
