Abstract
Cyclic variations and turbulence characterisation are considered in the context of in-cylinder flows. Three methods of data analysis, namely ensemble averaging, high pass filtering and cycle-by-cycle smoothing, are applied to velocity data obtained by laser Doppler velocimetry in a model axisymmetric and a realistic engine configuration. The interpretation of the results is supported by similar analysis of a steady-state simulation of in-cylinder flow with emphasis on the discrimination between random and deterministic flow variations. The results suggest that it is not always possible to identify cyclic variations as deterministic processes and that turbulence estimates based on filtering techniques may be misleading. The differences in the estimates of mean values are, however, small.
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Arcoumanis, C.; Hadjiapostolou, A.; Whitelaw, J. H. 1987: Swirl center precession in engine flows. SAE Paper 870370
Bendat, S. J.; Piersol, A. G. 1971: Random data: analysis and measurement procedures. New York: Wiley
Catania, A. E.; Mittica, A. 1985: Cycle-by-cycle correlation and spectral analysis of IC engine turbulence. In: Proc. 3rd Int. Symp. on Flows in Internal Combustion Engines, Miami Beach/ FL. ASME-FED 28, 39–46
Daily, J. W. 1988: Cycle-to-cycle variations: a chaotic process? Combust. Sci. Technol. 57, 149–162
Fanser, T. D.; French, D. T. 1988: Cycle-resolved laser-velocimetry measurements in a reentrant bowl-in-piston engine. SAE Paper 880377
Glover, A. R. 1986: Towards bias-free estimates of turbulence in engines. 3rd Int. Symp. on Applications of Laser Anemometry to Fluid Mechanics, Lisbon, 5.3
Hall, M. J.; Bracco, F. V.; Santavicca, D. A. 1986: Cycle resolved velocity and turbulence measurements in an IC engine with combustion. SAE Paper 860320
Liou, T.-M.; Santavicca, D. A. 1983: Cycle resolved turbulence measurements in a ported engine with and without swirl. SAE Paper 830419
Liou, T.-M.; Santavicca, D. A. 1985: Cycle resolved LDV measurements in a motored IC engine. J. Fluids Eng. 107, 232–240
Namekawa, S.; Ryu, H.; Asanuma, T. 1988: LDA measurement of turbulent flow in a motored and firing spark-ignition engine with a horizontal prechamber. SAE Paper 881636
Rask, R. B. 1981: Comparison of window, smoothed-ensemble, and cycle-by-cycle data reduction techniques for laser Doppler anemometer measurements of in-cylinder velocity. In: Fluid mechanics of combustion systems (eds. Morel, T; Lohmann, R. P.; Rackley, J. M.). New York: ASME
Reinsch, C. H. 1967: Smoothing by spline functions. Numer. Math. 10, 177–183
Vafidis, C. 1984: Influence of induction swirl and piston configuration on air flow in a four-stroke model engine. Proc. Inst. Mech. Eng. London 198 C, 8, 71–79
Vafidis, C.; Vorropoulos, G.; Whitelaw, J. H. 1987: Effects of intake port and combustion chamber geometry on in-cylinder turbulence in a motored reciprocating engine. In: Proc. Symp. on Fluid Flow and Heat Transfer in Reciprocating Machinery, Boston/MA. ASME-FED 62, 9–15
Winsor, R. E.; Patterson, D. J. 1974: Mixture turbulence — A key to cyclic combustion variation. SAE Paper 730086
Witze, P. O.; Martin, J. K. 1984: Cyclic-variation bias in spark ignition engine turbulence measurements. 2nd Int. Symp. on Applications of Laser Anemometry to Fluid Mechanics, Lisbon, 9.4
Witze, P. O.; Martin, J. K.; Borgnakke, C. 1984: Conditionally-sampled velocity and turbulence measurements in a spark ignition engine. Combust. Sci. Technol. 36, 301
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Enotiadis, A.C., Vafidis, C. & Whitelaw, J.H. Interpretation of cyclic flow variations in motored internal combustion engines. Experiments in Fluids 10, 77–86 (1990). https://doi.org/10.1007/BF00215014
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DOI: https://doi.org/10.1007/BF00215014