PIN FINNED COOLING: INVESTIGATION OF DESIGN AND PERFORMANCE

Abstract

Gas turbines play an important part in industrialized society and as power demands is increasing, gas turbine power output and thermal efficiency must increase as well. The energy of burning gases and air, which is at high temperature and pressure, is harnessed by the gas turbine power plant by expanding through numerous rings of fixed and moving blades. The principal failure mode of gas turbine blades is 'creep', which is caused by thermal loads. Despite their thickness, turbine blades break before compressor blades. Blade cooling is critical because it permits gas turbines to operate at temperatures above the melting point of the blade material, which is +300°C. Pin-fin is one of the most effective ways used for cooling of gas turbine blades. In the present work, effect of pin fin has been presented with the help of Numerical modelling using Ansys Fluent. The combinations of two different shaped fins are taken into account i.e., one with 45 tilted elliptical shape and other with diamond shape arranged in staggered array is selected. Streamwise and spanwise directions are taken as Sx/D = 2.5 and Sy/D = 2.5 whereas H/D = 2 is taken. In current numerical study we determined the Nusselt No. and friction Factor through pin-fin array for the Reynolds number between 10000 to 50000. Results showed that with increase Reynolds no. thermal performance of pin-fin decreases.