DOIONLINE

DOIONLINE NO - IJMPE-IRAJ-DOIONLINE-5365

Publish In
International Journal of Mechanical and Production Engineering (IJMPE)-IJMPE
Journal Home
Volume Issue
Issue
Volume-4,Issue-8  ( Aug, 2016 )
Paper Title
Conjugate CFD With Heat Transfer Analysis of Turbine Rim
Author Name
Arjun Kumar .D, Sivasankara Reddy, K.S.Shashi Shekar
Affilition
M.Tech, Project trainee, HTG, GTRE, DRDO Scientist ‘F’, HTG, GTRE, DRDO, Corresponding author Professor, Mechanical Engineering Dept., SIT, Tumkur
Pages
93-98
Abstract
The study of secondary air flow in the region in and around the turbine disks is very important due to the high operating temperatures of the turbine. During the operation Overheated turbine disks results in catastrophic failures. Cooling of a turbine rotor blade is typically carried out by the compressor exit air. This air bypasses the combustion chamber and is passed to the root of the rotor blade. The pre swirler nozzles are used to inject the cool air into root of the blade channels of the turbine disc. Also there are radial and axial clearances between the turbine rotor and the adjacent stator walls. To prevent hot gas from the main stream leaking into the internal cavities damagingthe components in the cavities, secondary air at higher pressure than gas pressure is passed through the rotor stator gaps into the gas path. This is to prevent hot gas ingestion, and is called purge air. The air tapped from the compressor exit is used for bothblade cooling and to prevent hot gas ingestion(purge air).In a typical gas turbine engine analyzed here, air tapped from the compressor exit reaches the turbine region and branches into two streams, one for blade cooling and another for purging purpose. The relative proportions of cooling air and purge air is very critical. Too little cooling air results in blade failure. On the other hand too little purge air results in hot gas ingestion into cavities, and all associated components will fail or get damaged. Thus, it is very important to design and estimate the correct flow split. Also, flows in this region are very complex, the domain bounded by rotor on one side, stator on the other side presence of labyrinth seal and heat transfer. To understand the flow physics, the heat transfer and correct flow split, a conjugate CFD analysis with heat transfer is carried out. In This paper the 3D sectorial numerical simulations are carried out by using the FLUENT 14.5. All the physics of a rotating system and conjugate heat transfer are captured. Flow patterns, pressure distributions, temperature distributions in both the fluid and metal components are obtained. Keywords— Pre Swirler Nozzles, Purge Air, Gas Ingestion, Blade Cooling Air Path.
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