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A Novel Model for Computing the Trapping Efficiency and Residual Gas Fraction Validated with an Innovative Technique for Measuring the Trapping Efficiency
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 09, 2008 by SAE International in United States
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The paper describes a novel method for calculating the residual gas fraction and the trapping efficiency in a 2 stroke engine. Assuming one dimensional compressible flow through the inlet and exhaust ports, the method estimates the instantaneous mass flowing in and out from the combustion chamber; later the residual gas fraction and trapping efficiency are estimated combining together the perfect displacement and perfect mixing scavenging models. It is assumed that when the intake port opens, the fresh mixture is pushing out the burned charge without any mixing and after a multiple of the time needed for the largest eddy to perform one rotation, the two gasses are instantly mixed up together and expelled. The result is a very simple algorithm that does not require much computational time and is able to estimate with high level of precision the trapping efficiency and the residual gas fraction in 2 stroke engines. The tuning and the validation of this algorithm are performed by measuring the trapping efficiency. These measurements are conducted with an innovative technique which consists in measuring the inlet and exhaust temperature, and calculation of the blow down temperature from the pressure trace. The model was tested using a mini high speed 2 stroke HCCI engine fuelled with diethyl ether between 10,800 and 19,000 [rpm].
CitationManente, V., Tunestål, P., and Johansson, B., "A Novel Model for Computing the Trapping Efficiency and Residual Gas Fraction Validated with an Innovative Technique for Measuring the Trapping Efficiency," SAE Technical Paper 2008-32-0003, 2008, https://doi.org/10.4271/2008-32-0003.
Data Sets - Support Documents
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- Hopkinson B. “The Charging of a Two Cycle Internal Combustion Engines”, Trans. NE Coast Inst. Engnrs. Shipbuilders, Vol.30, 1914, p.433.
- Benson R.S., Prandham P.J., “A Method for Obtaining a Quantitative Assessment of the Influence of Charge Efficiency on Two Stroke Engine Performance”, Int. J. Mech. Sci., Vol. 11, p.303, 1969.
- Blair G., ‘The Basic Design of Two Stroke Engines’, SAE R - 104
- Sammons H., “A Single Cycle Test Apparatus for Studying Loop Scavenging in a Two Stroke Engine”, Proc. I. Mech. E., Vol. 160, 1949, p.233.
- Sanborn D.S., Blair G.P., Kenny R.G., Kingbury A.H., “Experimental Assessment of Scavenging Efficiency of Two Stroke Cycle Engine”, SAE Intnl. Off-High Way Vehicle Meeting, Milwaukee, Wisconsin, September, 1980, SAE 800975.
- Manente V., Tunestål P., Johansson B., “Influence of the compression ratio on the performance and emissions of a mini HCCI engine fuelled with DEE”, SAE 07FFL-40
- Sher E., “Investigating the Gas Exchange Process of a two Stroke Cycle Engine with a Flow Visualization Test Rig”, Israel J. Technol. Vol. 20, p.127-136, 1982.
- Blair G., ‘Design and Simulations of Two Stroke Engines’
- Manente V. et al., “A Study of Glow Plug Ignition Engine by Chemiluminescence Images”, SAE 2007-01-1884