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Eliminating Rating Effects on Turbocharged Diesel Response
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English
Abstract
It is well known that the response of turbocharged diesel engines deteriorates as rated mean effective pressure (BMEP) Increases, for a given maximum power output. This is a problem for diesel generating sets but is now also causing concern on vehicle engines as ratings increase.
The objective of the paper is to present the trade-off between increased BMEP (rating) and response and to outline methods of improving response. A sophisticated and detailed transient engine simulation is first validated against test data for a high BMEP engine and is then used to compare the response of 16, 12, 8, 6 and 4 cylinder derivatives of the same 4-stroke diesel engine, when all are rated at the same maximum speed and power. Thus, rated speed BMEP increases from the naturally aspirated V16 (6.78 bar) through turbocharged V12, turbocharged and charge cooled V8 and L6 engines to a 2-stage turbocharged and charge cooled L4 (27.1 bar). The acceleration time of these engines varies greatly, the 4 cylinder taking 2.4 times as long to achieve maximum speed.
Various methods of improving response are examined, some well known and others novel. Some, such as reduced inertia and variable geometry are developments for which the turbocharger manufacturer is responsible. Others, such as variable fuel injection timing or valve timing, can be developed by the engine maker. It is shown that several options for development can substantially improve response until it is close to that of a naturally aspirated engine, whatever the rating of the engine.
Authors
Citation
Watson, N., "Eliminating Rating Effects on Turbocharged Diesel Response," SAE Technical Paper 840134, 1984, https://doi.org/10.4271/840134.Also In
References
- Watson N. Janota M.S. Turbocharging the internal Combustion Engine Macmillan Press London 1982
- Watson N. Marzouk M. A Non-linear Digital Simulation of Turbocharged Diesel Engines under Transient Conditions Trans. SAE Sect. A, 770123 1977
- Watson, N. Marzouk M. Pilley. A. D. A Combustion Correlation for Diesel Engine Simulation SAE 800029 86 1980
- Watson. N. Transient Performance Simulation and Analysis of Turbocharged Diesel Engines SAE 810338 1981
- Watson, N. Marzouk M. Baazaari. Z. An Evaluation of 2-stage Turbocharging For Efficient, High-output, Diesel Engines ASME 78-DGP-2 1978
- Andre Talamon. T. New Aspects of Turbocharger Utilization with the Hyperbar Parallel Supercharging. Paper C66/78 I. Mech. E., Turbocharging and Turbochargers 1978
- Watson. N. Resonant Intake and Variable Geometry Turbocharging Systems for a V8 Diesel Engine I. Mech. E., paper C41/82, Turbocharging and Turbochargers, 1982 and Proc. I.Mech.E 197A 1983
- Flaxington D. Szczupak. D.T. Variable Area Radial inflow Turbines. Paper C36/82 I. Mech. E., Turbocharging and Turbochargers, 1982
- Wallace, F. J. Way R. J. B. Baghery. A. Variable Geometry Turbocharging - The Realistic Way Forward SAE 810336 1981
- Arvin J. R. Osborn. N. L. Design Features and Operating Experiences of Aerodyne Dallas VATN Turbocharger SAE 830013 1983