This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Turbo-Discharging: Predicted Improvements in Engine Fuel Economy and Performance
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 12, 2011 by SAE International in United States
Annotation ability available
The importance of new technologies to improve the performance and fuel economy of internal combustion engines is now widely recognized and is essential to achieve CO₂ emissions targets and energy security. Increased hybridization, combustion improvements, friction reduction and ancillary developments are all playing an important part in achieving these goals. Turbocharging technology is established in the diesel engine field and will become more prominent as gasoline engine downsizing is more widely introduced to achieve significant fuel economy improvements.
The work presented here introduces, for the first time, a new technology that applies conventional turbomachinery hardware to depressurize the exhaust system of almost any internal combustion engine by novel routing of the exhaust gases. The exhaust stroke of the piston is exposed to this low pressure leading to reduced or even reversed pumping losses, offering ≻5% increased engine torque and up to 5% reduced fuel consumption. This method has the distinct advantage of providing performance and fuel economy improvements without significant changes to the structure of the engine, the combustion system or lubrication system.
The Turbo-Discharging concept is introduced and analyzed. A combination of filling/emptying models and 1-D gas dynamic simulations were used to quantify the energy flows and identify optimum valve timings and turbomachine characteristics. 1-D gas dynamic simulation was then used to predict primary fuel economy benefits from Turbo-Discharging. Secondary benefits, such as extended knock limits are then discussed.
CitationWilliams, A., Baker, A., and Garner, C., "Turbo-Discharging: Predicted Improvements in Engine Fuel Economy and Performance," SAE Technical Paper 2011-01-0371, 2011, https://doi.org/10.4271/2011-01-0371.
- Shahed, S. Bauer, K. “Parametric Studies of the Impact of Turbocharging on Gasoline Engine Downsizing,” SAE Int. J. Engines 2 1 1347 1358 2009 10.4271/2009-01-1472
- Flierl, R. Paulov, M. Knecht, A. Hannibal, W. “Investigations with a Mechanically Fully Variable Valve Train on a 2.01 Turbo Charged Four Cylinder Engine,” SAE Technical Paper 2008-01-1352 2008 10.4271/2008-01-1352
- Mori, M. Yamagami, T. Oda, N. Hattori, M. et al. “Current Possibilities of Thermoelectric Technology Relative to Fuel Economy,” SAE Technical Paper 2009-01-0170 2009 10.4271/2009-01-0170
- Ringler, J. Seifert, M. Guyotot, V. Hübner, W. “Rankine Cycle for Waste Heat Recovery of IC Engines,” SAE Int. J. Engines 2 1 67 76 2009 10.4271/2009-01-0174
- Lyu, M. Doo, B. Ku, Y. “A Study of Vehicle Fuel Economy Improvement Potential by Optimization of the Cooling and Ancillary Systems of a Heavy Duty Engine,” SAE Technical Paper 2007-01-1772 2007 10.4271/2007-01-1772
- Improving fuel efficiency with laser surface textured piston rings Etsion, I. Sher, E. Tribology International 42 542 547 2009
- Möller, C. Johansson, P. Grandin, B. Lindström, F. “Divided Exhaust Period - A Gas Exchange System for Turbocharged SI Engines,” SAE Technical Paper 2005-01-1150 2005 10.4271/2005-01-1150
- Improvements in or relating to internal combustion engines Society Rateau. British patent no. 12,227/22 1924
- Fundamentals of Turbocharging Baines, N.C. Concepts NREC Vermont, USA 2005