CFD analysis of combustion liner with different geometry holes for effusion film cooling

Abstract

The advanced gas turbine is designed to operate at higher temperature to increase thermal efficiency. Since the gas temperature exceed the allowable material temperature, so cooling techniques of turbine components are more important. Effusion film cooling is an external and highly sophisticated cooling technology, which protects the liner by injecting the secondary cooler fluid at particular locations over the liner surface exposed to the higher gas temperatures. The injected fluid forms as a thin layer (film) on the liner surface and protects the liner surface from higher gas temperatures. In elliptical geometry of holes in plate for effusion cooling is studied for the samples made of adiabatic and conductivity material. To increase the life of combustion chamber it is essential to know the amount of cooling air to be used for cooling of the liner. For effusion film cooling, geometry of the hole is one of the key parameters which influences the coolant mass flow rate and it spread over the liner surface thus affecting the cooling effectiveness. The commercially available FloEFD software is used for calculating the surface temperature and effusion cooling effectiveness distribution throughout the sample plate and result values are in good agreement and this has given confidence to usage of the commercial software FloEFD for predicting the film effectiveness. After result validation finally concluded that span wise elliptical hole (Config-2) have more effectiveness than circular holes.