FLOW FIELD ANALYSIS OF AN AUTOMOTIVE MIXED FLOW TURBOCHARGER TURBINE

M. H. Padzillah, S. Rajoo, R. F. Martinez-Botas

Abstract


Traditionally, the turbocharger has been an essential tool to boost the engine power especially the diesel engine. However, in recent years it is seen as an enabling technology for engine downsizing of all internal combustion engines. The use of mixed flow turbine as replacement for radial turbine in an automotive turbocharger has been proven to deliver better efficiency at high loading conditions. Furthermore, the use vanes that match the geometrical properties at the turbine leading edge could further increase its performance. However, improvement on the overall turbocharger performance is currently limited due to lack of understanding on the flow feature within the turbine stage. Therefore, the use of validated Computational Fluid Dynamics (CFD) in resolving this issue is necessary. This research attempts to provide description of flow field within the turbocharger turbine stage by plotting velocity and pressure contours at different planes. To achieve this aim, a numerical model of a full stage turbocharger turbine operating at 30000rpm under its optimum condition (pressure ratio of 1.3) is developed and validated. Results indicated strong tip-clearance flow downstream of the turbine mid-chord. Evidence of flow separations at the turbine leading edge are also seen despite turbine operating at its optimum condition.


Keywords


Computational fluid dynamics, pulsating flow, mixed flow turbine

Full Text:

PDF

References


Lymberopoulos, N., Baines, N. C. and Watson, N. 1988. Flow in Single and Twin Entry Radial Turbine Volutes. ASME Gas Turbine Aeroengine Congr. 88-GT-59.

Barr, L. and Spence, S. W. T. 2008. Improved Performance of a Radial Turbine Through the Implementation of Back Swept Blading. Proc ASME Turbo Expo No. GT2008-50064.

Barr, L., Spence, S., Thornhill, D. and Eynon P. 2009. A Numerical and Experimental Performance Comparison of an 86 MM Radial and Back Swept Turbine. Proc ASME Turbo Expo No. GT2009-59366.

Walkingshaw, J., Spence, S., Ehrhard, J. and Thornhill, D. 2010. A Numerical Study of the Flow Fields in a Highly Off-Design Variable Geometry Turbine. Proc ASME Turbo Expo No. GT2010-22669.

Padzillah, M. H., Rajoo, S. and Martinez-Botas, R. F. 2014. Influence of Speed and Frequency towards the Automotive Turbocharger Turbine Performance under Pulsating Flow Conditions. Energy Convers. Manag. 80: 416–428.

Denton, J. D. 2010. Some Limitations of Turbomachinery CFD. In ASME Turbo Expo 2010: Power for Land, Sea and Air. 1–11.

Dale, A. and Watson, N. 1986. Vaneless Radial Turbocharger Turbine Performance. Proc. IMechE Int. Conf. Turbocharging Turbochargers (Mechanical Eng. Publ. London). 65–76.

Szymko, S. 2006. The Development of an Eddy Current Dynamometer for Evaluation of Steady and Pulsating Turbocharger Turbine Performance. PhD Thesisi, Imperial College of Science, Technology and Medicine, University of London.

Rajoo S. 2007. Steady and Pulsating Performance of a Variable Geometry Mixed Flow Turbochager Turbine. PhD Thesis, Imperial College of Science, Technology and Medicine, University of London.

Abidat M. 1991. Design and Testing of a Highly Loaded Mixed Flow Turbine. PhD Thesisi, Imperial College of Science, Technology and Medicine, University of London.

Padzillah, M. H., Rajoo, S. and Martinez-Botas, R. F. 2012. Numerical Assessment of Unsteady Flow Effects on a Nozzled Turbocharger Turbine. Proc ASME Turbo Expo No. GT2012-69062.

Japikse, D., Baines and N. C. 1994. Introduction to Turbomachinery. Oxford University Press.

Palfreyman, D. and Martinez-Botas, R. 2002. Numerical Study of the Internal Flow Field Characteristics in Mixed Flow Turbines. Proc ASME Turbo Expo No. GT2002-30372.

Palfreyman, D. 2004. Aerodynamics of a Mixed Flow Turbocharger Turbine under Steady and Pulse Flow Conditions: A Numerical Study. PhD Thesis, Imperial College of Science, Technology and Medicine, University of London.




DOI: https://doi.org/10.11113/jt.v77.6150

Refbacks

  • There are currently no refbacks.


  

Copyright © 2012 Penerbit UTM Press, Universiti Teknologi Malaysia.
Disclaimer : This website has been updated to the best of our knowledge to be accurate. However, Universiti Teknologi Malaysia shall not be liable for any loss or damage caused by the usage of any information obtained from this web site.
Best viewed: Mozilla Firefox 4.0 & Google Chrome at 1024 × 768 resolution.