Numerical investigation into the effect of direct fuel injection on thermal stratification in HCCI engine
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Faculty of Mechanical Engineering at Lublin University of Technology
Division of Aircraft Engines at Warsaw University of Technology
Publication date: 2017-05-01
Combustion Engines 2017,169(2), 137–140
Despite the fact that HCCI engines are distinguished by mixture homogeneity, some degree of stratification always appears inside a combustion chamber. It is especially applied to residual effect engines utilizing negative valve overlap. Mixture stratification is a result of the imperfect mixing of fresh air with trapped residuals. Direct fuel injection introduces stratification as well, due to fuel vaporization. As a consequence, the temperature within the combustion chamber is uneven. Thermal stratification affects auto-ignition timing and combustion evolution in a high extent. The purpose of this study was to evaluate a degree of thermal stratification in HCCI engine utilizing negative valve overlap. Investigations were performed using three-dimensional CFD model of the combustion system, made by using AVL FIRE software. Simulations were realized for various timings of fuel injection into the cylinder. It was found that fuel injection timing had a significant effect on the thermal stratification and resulting auto-ignition timing.
ALEIFERIS, P., CHARALAMBIDES, A., HARDALUPAS, Y. et al. Modelling and experiments of HCCI engine combustion with charge stratification and internal EGR. SAE Technical Paper. 2005, 2005-01-3725.
GUOHONG, T., ZHI, W., JIANXIN, W. et al. HCCI combustion control by injection strategy with negative valve overlap in a GDI engine. SAE Technical Paper. 2006, 2006-01.0415.
HUNICZ, J., GĘCA M., KORDOS P. An experimental study of boosted gasoline HCCI engine under different direct fuel injection strategies. Experimental Thermal and Fluid Science. 2015, 4.
HUNICZ, J., KORDOS, P. Experimental study of the gasoline engine operated in spark ignition and controlled auto-ignition combustion modes. SAE Technical Paper. 2009, 2009-01-2667.
KAWASAKI, K., HIROTA, K., NAGATA, S. et al. Improvement of natural-gas HCCI combustion by internal EGR by means of exhaust valve re-opening. SAE Int. J. Engines. 2010, 2(2), 733-739.
MASE, Y., KAWASHIMA, J., SATO, T., EGUCHI, M. Nissan's new multivalve DI diesel engine series. SAE Technical Paper. 1998, 981039.
NAJT, P., FOSTER, D.E. Compression-ignited homogeneous charge combustion. SAE Technical Paper. 1983, 830264.
OGURA, M., SASAKI, T., KAWAGUCHI, Y. HCCI combustion control by intake and exhaust continuous variable valve timing mechanism in premixed gasoline engine. SAE Technical Paper. 2004, 2004-32-0096.
PULKRABEK, W.W. Engineering fundamental of the internal combustion engine 2nd edition. Pearson Prentice-Hall. Upper Saddle River, NJ, 2004.
SJÖBERG M., DEC, J.E. Comparing late-cycle autoignition stability for single- and two-stage ignition fuels in HCCI engines. Proceedings of the Combustion Institute. 2007, 31, 2895-2902.
SJÖBERG, M., DEC, J., HWANG, W. Thermodynamic and chemical effects of EGR and its constituents on HCCI autoignition. SAE Technical Paper. 2007, 2007-01-0207.
SJÖBERG, M., DEC, J.E., CERNANSKY, N. Potential of thermal stratification and combustion retard for reducing pressure-rise rates in HCCI engines, based on multi-zone modeling and experiments. SAE Technical Paper. 2005, 2005-01-0113.
STANGLMAIER, R.H., ROBERTS, C.E. Homogeneous charge compression ignition (HCCI): benefits, compromises, and future engine applications. SAE Technical Paper. 1999, 1999-01-3682.