Journal Article
Effect of Actual Gaps and Leakage Flow of Variable Geometry Turbine on its Performance
2012-04-16
2012-01-0708
Recently, a variable flow capacity turbine has become important for automotive turbochargers to satisfy the demands of engine performance and emissions. Especially, a variable nozzle turbine is an indispensable component for diesel engines of both passenger and commercial vehicles to realize a high boosting from the low end to the rated engine condition. On the other hand, since a variable nozzle turbine has several gaps and clearances around movable nozzle vanes to ensure the smooth operation under the hot gas condition, therefore there is a possibility that these complicated geometries may cause the additional loss and the turbine efficiency decrement. The authors conducted detailed CFD calculations of a variable nozzle turbine taking account of nozzle vane clearance, strut pins, spindles.
