Vortex motion induced by the piston of an internal combustion engine

Daneshyar, H.; Fuller, D. E.; Deckker, B. E. L.

doi:10.1016/0020-7403(73)90037-4

Cited by 22 publications

(5 citation statements)

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“…Various studies (Clarkson et al, 2001;Daneshyar et al, 1973;Griffiths et al, 1993a;Lee and Hochgreb, 1998;Mittal and Sung, 2006;Wü rmel and Simmie, 2005) have shown the existence of a roll-up vortex due to piston motion, which leads to the mixing of pockets of cold gases from wall boundary layer with the hot gases in the core region. This resulting non-uniformity of the reacting core can cause serious discrepancies between the data taken from different RCMs.…”

Section: Optimization Of the Reactor Piston Crevicementioning

confidence: 99%

A Rapid Compression Machine for Chemical Kinetics Studies at Elevated Pressures and Temperatures

Mittal

Sung

2007

Combustion Science and Technology

197

159

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Section: Optimization Of the Reactor Piston Crevicementioning

confidence: 99%

A Rapid Compression Machine for Chemical Kinetics Studies at Elevated Pressures and Temperatures

Mittal

Sung

2007

Combustion Science and Technology

197

159

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“…The remaining 15% is the result of inviscid entrainment. The experiments of Daneshyar et al (1973) involved moving a rectangular piston with a sinusoidal velocity characteristic and using dye for flow visualization. As in the study of Tabaczynski et al (1970), in order to develop an analytic expression for the vortex scaling, it was assumed that the area of the boundary layer forming over the duct wall is proportional to the cross-sectional area of the vortex.…”

Section: Introductionmentioning

confidence: 99%

“…Re apparatus was constant for the duration of an experiment. Tabaczynski, Hoult & Keck (1970) and Daneshyar, Fuller & Deckker (1973) conducted flow visualization experiments to examine the transient development of this class of vortex. Tabaczynski et al (1970) postulated that the cross-sectional area of the vortex was a function of the piston speed and the distance the piston had moved from rest.…”

Section: Introductionmentioning

confidence: 99%

Vortex formation in front of a piston moving through a cylinder

Allen

Chong

2000

J. Fluid Mech.

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This paper contains the details of an experimental study of the vortex formed in front of a piston as it moves through a cylinder. The mechanism for the formation of this vortex is the removal of the boundary layer forming on the cylinder wall in front of the advancing piston. The trajectory of the vortex core and the vorticity distribution on the developing vortex have been measured for a range of piston velocities. Velocity field measurements indicate that the vortex is essentially an inviscid structure at the Reynolds numbers considered, with viscous effects limited to the immediate corner region. Inviscid flow is defined in this paper as being a region of the flow where inertial forces are significantly larger than viscous forces. Flow visualization and vorticity measurements show that the vortex is composed mainly of material from the boundary layer forming over the cylinder wall. The characteristic dimension of the vortex appears to scale in a self-similar fashion, while it is small in relation to the apparatus length scale. This scaling rate of t 0.85+0.7m , where the piston speed is described as a power law At m , is somewhat faster than the t 3/4 scaling predicted by Tabaczynski et al. (1970) and considerably faster than a viscous scaling rate of t 1/2 . The reason for the structure scaling more rapidly than predicted is the selfinduced effect of the secondary vorticity that is generated on the piston face. The vorticity distribution shows a distinct spiral structure that is smoothed by the action of viscosity. The strength of the separated vortex also appears to scale in a self-similar fashion as t 2m+1 . This rate is the same as suggested from a simple model of the flow that approximates the vorticity being ejected from the corner as being equivalent to the flux of vorticity over a flat plate started from rest. However, the strength of the vorticity on the separated structure is 25% of that suggested by this model, sometimes referred to as the 'slug' model. Results show that significant secondary vorticity is generated on the piston face, forming in response to the separating primary vortex. This secondary vorticity grows at the same rate as the primary vorticity and is wrapped around the outside of the primary structure and causes it to advect away from the piston surface.

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“…However, in the boundary layer conservation equations 1n the gas this contribution, which would correspond to a pcpv~~ term, has been omitted.' I Also omitted in the boundary layer equations is a mixing effect resulting from the vortex that forms at•the piston wall interface [8,19,20]. omissions are consistent with the slightly smaller results for qw,g.…”

mentioning

confidence: 71%

Heat transfer during piston compression including side wall and convection effects

Greif¹,

Namba²,

Nikanham³

1979

International Journal of Heat and Mass Transfer

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The unsteady heat flux from a non-reacting gas to the sidewalls of a channel has been determined during the piston compression of a single stroke. For small changes in the wall temperature, the heat flux may'be determined solely from the va.riation of the temperature outside the boundary layer or, alternatively, from the piston trajectory. Results for the heat transfer coefficient are also presented and exhibit a non-monotonic variation with respect to time.

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Vortex motion induced by the piston of an internal combustion engine

Cited by 22 publications

References 1 publication

A Rapid Compression Machine for Chemical Kinetics Studies at Elevated Pressures and Temperatures

A Rapid Compression Machine for Chemical Kinetics Studies at Elevated Pressures and Temperatures

Vortex formation in front of a piston moving through a cylinder

Heat transfer during piston compression including side wall and convection effects

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