This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Predictions of the Performance of a Radial Turbine with Different Modeling Approaches: Comparison of the Results from 1-D and 3-D CFD
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 12, 2010 by SAE International in United States
Annotation ability available
In this paper, the performance of a radial turbine working under pulsatile flow conditions is computed with two different modeling approaches, time resolved 1-dimensional (1-D) and 3-dimensional (3-D) CFD. The 1-D modeling approach is based on measured turbine maps which are used to compute the mass flow rate and work output from the turbine for a given expansion ratio and temperature at the inlet. The map is measured under non-pulsatile flow conditions, and in the 1-D method the turbine is treated as being a quasi-stationary flow device. In the 3-D CFD approach, a Large Eddy Simulation (LES) turbulence approach is used. The objective of LES is to explicitly compute the large scales of the turbulence while modeling the effects of the unresolved scales.
Three different cases are considered, where the simplest case only consist of the turbine and the most complex case consist of an exhaust manifold and the turbine. Both time resolved data, such as pressure ratio, temperature and shaft torque and time mean data from the two different modeling approaches are compared. The results show that the computed time mean shaft power differs between the two different modeling approaches with as much as 100%. Since the considered operation point for the engine in this study is 1500 rpm with wide open throttle, the turbine operates in an area where the turbine map is extrapolated. Only by using a few operation points from CFD to extend the map, an improvement is achieved for the 1-D results, but still the deviation is large. Also, the pressure ratio and temperature drop over the turbine differs for the used modeling approaches. The causes for the deviations are assessed and discussed to get a better understanding of eventually limitations of the 1-D modeling approach.
CitationHellstrom, F., Renberg, U., Westin, F., and Fuchs, L., "Predictions of the Performance of a Radial Turbine with Different Modeling Approaches: Comparison of the Results from 1-D and 3-D CFD," SAE Technical Paper 2010-01-1223, 2010, https://doi.org/10.4271/2010-01-1223.
- Gamma Technologies. GT-Power User manual version 6.1, 2004.
- Bodin-Ek Erik. “Calibration of a transient GT-power model of a SI PFI turbo Engine”. TRITA-MMK 2008:1 MFM117, 2008.
- Westin Fredrik. “Simulation of turbocharged SI engines with focus on the turbo”. PhD thesis, Thesis TRITA MMK 2005:05, ISSN 1400 1179, ISRN/KTH/MMK/R 05/05-SE, 2005.
- Winterbone D.E. and Pearson R.J.. “Turbocharger turbine performance under unsteady flow; a review of experimental results and proposed models”. IMechE paper C554/031, 1998.
- Lam J. K. W., Roberts Q. D. H., and McDonnell G. T.. “Flow modeling of a turbocharger turbine under pulsating flow”. ImechE Conference Transactions from 7th International Conference on Turbochargers and Turbocharging, 14-15 May London UK, pages 181-196, 2002.
- Winterbone D. E., Nikpour B., and Frost H.. “A contribution to the understanding of turbocharger turbine performance in pulsating flow”. International Conference on Internal Combustion Research, Paper no C433/011. Inst. of Mech. Engrs., pages 19-28, 1991.
- Hellstrom F and Fuchs L. “Numerical computations of pulsatile flow in a turbo-charger”. AIAA-2008-073, 46th AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada, 7-10 January 2008, 2008.
- Hellstrom F and Fuchs L. “Numerical computation of the pulsatile flow in a radial turbocharger with realistic inflow conditions from an exhaust manifold”. GT 2009-59619, ASME Turbo Expo 2009, Power for Land, Sea and Air, Orlando, Florida, USA, 2009.
- Karamanis N., Martinez-Botas R.F., and Su C.C.. “Mixed flow turbines: Inlet and exit flow under steady and pulsating conditions”. ASME Journal of Turbomachinery, 123:359-371, 2001.
- Dale A., Watson N., and Cole A.C.. “The development of a turbocharger turbine test facility”. Inst. Engrs. Seminar, pages pp. 75-84, 1988.
- Flaxington A and Swain E. “Turbocharger aerodynamic design”. Proceedings of the Institute of Mechanical Engineers, Vol 213 Part C:43-57, 1999.
- Shaaban S. and Seume J.R.. “Analysis of turbocharger non-adiabatic performance”. ImechE Conference Transactions from 8th International Conference on Turbochargers and Turbocharging, pages 119-130, 2006
- Palfreyman D. and Martinez-Botas R.F.. “The pulsating flow field in a mixed flow turbocharger turbine: An experimental and computational study”. ASME, Journal of Turbomachinery, 127:144-155, 2005.
- Hellstrom F. and Fuchs L.. “Effects of inlet conditions on the turbine performance of a radial turbine”. GT 2008-51088, ASME Turbo Expo 2008, Power for Land, Sea and Air, Berlin, Germany, 2008.
- Fureby C. and Grinstein F. F., 2002. “Large eddy simulation of high Reynolds number free and wall-bounded flows”, Journal of Computational Physics, 181, pp. 68-97.
- Hellstrom F., and Fuchs L., 2007. “Numerical computations of steady and unsteady flow in bended pipes”. AIAA-2007-4350, 37th AIAA Fluid Dynamics Conference and Exhibit, Miami, FL, June 25-28.
- CD-ADAPCO, 2005, Methodology manual, STAR-CD version 3.26
- Hellstrom F. and Burenius R., “On numerical computations of the unsteady flow in a radial turbine: Assessment and validation of different modeling strategies” Submitted to ASME Turbo Expo 2010, Glasgow, Scotland