The results of a simple simulation model incorporating the cyclic fluctuations in flame velocity resulting from the corresponding variability in turbulence onset and generation imply that at low load conditions such fluctuations can induce changes of the order of many per cent in the indicated mean effective pressure (i.m.e.p.). The methods employed here are relatively unsophisticated; however, the scales of the effects are sufficient to sound at least a cautionary note to the introduction of processes such as tumble collapse into lean burn technologies without taking due notice of the possible disadvantages.
Get full access to this article
View all access options for this article.
References
1.
GosmanA. D.TsuiY. Y.VafidisC.Flow in a model engine with a shrouded valve—a combined experimental and computational study. SAE paper 850498, 1985.
2.
LiouT.M.SantaviccaD. A.Cycle-resolved turbulence measurement in a ported engine with and without swirl. SAE paper 830419, 1983.
3.
LeCozJ.HenriotS.PinchonP.An experimental and computational analysis of the flow in a four-valve spark ignition engine—focus on cycle-resolved turbulence. SAE paper 90056, 1990.
4.
FurunoS.IguchiS.OishiK.InoueT.The effects of ‘inclination angle of swirl axis’ on turbulence characteristics in a 4-valve lean burn engine with SCV. SAE paper 902139, 1990.
5.
AndoH.SanbayashiD.KuwaharaK.IwachidoK.Characteristics of turbulence generated by tumble and its effects on combustion. International Symposium COMODIA 90, 1990, pp. 443–448.
6.
ArcoumanisC.HuZ.VafidisC.WhitelawJ. H.Tumbling motion: a mechanism for turbulence enhancement in spark-ignition engines. SAE paper 900060, 1990.
7.
EnotiadisA. C.VafidisC.WhitelawJ. H.Interpretation of cyclic flow variations in motored internal combustion engines. Exp. in Fluids, 1990, 10, 77–86.
8.
ArcoumanisC.EnotiadisA. C.WhitelawJ. H.Frequency analysis of tumble and swirl in motored engines. Proc. Instn Mech. Engrs, Part D, 1991, 205(D3), 177–184.
9.
ArcoumanisC.WhitelawJ. H.In-cylinder flow measurements in motored internal combustion engines. IMechE Conference on Internal combustion engine research in Universities, Polytechnics and Colleges, January 1991, paper C433/060, pp. 123–130 (Mechanical Engineering Publications, London).
10.
Abdel-GayedR. G.BradleyD.LauA. K. C.The straining of premixed turbulent flames. Twenty-second Symposium on Combustion, 1988, pp. 731–738 (The Combustion Institute).
11.
BradleyD.LauA. K.LawesM.Flame stretch rate as a determinant of turbulent burning. Phil. Trans., 1992, 338, 359–387.
12.
BradleyD.HynesJ.LawesM.SheppardC. G. W.Limitations to turbulence-enhanced burning rates in lean burn engines. IMechE International Conference on Combustion in engines—technology and applications, March 1988, paper C46/88, pp. 17–24 (Mechanical Engineering Publications, London).
13.
MorkovinM. V.ReshotkoE.Dialogue on progress and issues in stability and transition research. IUTAM Symposium on Laminar–turbulent transition (Eds ArnlD.MichelR.), Toulouse, France, 1989, pp. 1–29 (Springer-Verlag, Berlin).
14.
WeisbrotI.EinavS.WygnanskiI.The nonunique rate of spread of the two-dimensional mixing layer. Phys. of Fluids, 1982, 25, 1691–1693.
15.
LesieurM.Turbulence in fluids, 2nd revised edition, 1993 (Kluwer Academic Publishers, Dordrecht, The Netherlands).
16.
MelanderM. V.HussianF.Coupling between a coherent structure and fine-scale turbulence. Phys. Rev. E., 1993, 48, 2669–2689.
17.
SherE.HacohenJ.On the modeling of a SI 4-stroke cycle engine fueled with hydrogen-enriched gasoline. Int. J. of Hydrogen Energy, 1987, 12, 773–781.
18.
SherE.HacohenJ.Ignition delay and combustion duration in H2-enriched gasoline S.I. engines. Combust. Sci. and Technol., 1989, 65, 263–275.
19.
HacohenJ.BelmontM. R.ThurleyR. W. F.ThomasJ.MorrisE. L.BuckinghamD. J.Experimental and theoretical analysis of flame development and misfire phenomena in a spark-ignition engine. SAE paper 920415, 1992.
