Abstract:
In recent years CFD of turbo machinery flows has increased due to the enhanced
computational power. Current trend in industry is to reduce the engine weight, size
and enhance efficiency of engine components. This is done by manufacturing
blades of higher efficiencies and reduced blade count. These trends in
manufacturing result in highly loaded LPT blades. Due to the increased loading of
blades, there is always a possibility of flow separation at low Reynolds number.
In the last few decades, the reduction of fuel cost to weight ratio is the main
concern of aero-engine manufactures and aircraft industry. Turbine engines are
made to work properly and efficiently at high Reynolds's number (Re) conditions.
The boundary layers (BL) of low-pressure (LP) turbine blades have received a
great deal of attention due to the advent of high lift and ultra high lift LP turbines.
At cruising condition the Reynolds number is very low in engine (low density and
low velocity) and LP turbines performance suffers mainly from losses due to
separationon suction side of the blade.
In the present study T106A low pressure turbine profile has been used to study the
behavior of BL and subsequent control using the passive technique. Geometry
modification is being made to control the flow separation. Fluent® commercial
CFD code with Gamma-Theta transition model has been employed to study the
boundary layer separation at Reynolds number 91000. Passive devices control the
separation very effectively which reduced the pressure loss coefficient or increased
in efficiency of the LP Turbine.
