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A Study About In-Cylinder Flow and Combustion in a 4-Valve S.I. Engine
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Abstract
Lean-burn technology is now being reviewed again in view of demands for higher efficiency and cleanness in internal combustion engines. The improvement of combustion using in-cylinder gas flow control is the fundamental technology for establishing lean-burn technology, but the great increase in main combustion velocity due to intensifying of turbulence causes a deterioration in performance such as increase in heat loss and N0x.
Thus, it is desirable to improve combustion stability while suppressing the increase in main burn velocity as much as possible (1). It is expected that the fluid characteristics of the in-cylinder tumbling motion that the generated vortices during intake stroke breake down in end-half of compression stroke will satisfy the above requisition.
This study is concerned with the effects of enhancing of tumble intensity on combustion in 4-valve S. I. engines. Flow visualization by LLS (Laser Light Sheet) method was applied to the in-cylinder flow field that was varied by means of shurouded valve, and image processing technique using correlation method was utilized for estimating the tumble intensity in motored driving operation. And the breakdwon characteristics due to enhancing tumble were investigated by using numerical simulation code “KIVA”, moreover the results of flame propagation observations and of actual engine test were discussed synthetically to clarify the influence of flow field on combustion.
It was recognized that the breakdown process occurs at ealier stage before TDC (top dead center) according as tumble intensity is higher, so the tumble intensity and also turbulence intensity during main combustion would be a same level regardless of initial tumble intensity. Finally, it was confirmed that this flow characteristics can reduce the initital combustion period without significantly increase in main burn velocity.
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Kudou, H., Yamamoto, H., and Iida, Y., "A Study About In-Cylinder Flow and Combustion in a 4-Valve S.I. Engine," SAE Technical Paper 920574, 1992, https://doi.org/10.4271/920574.Also In
References
- Yamamoto Hiroyuki et. al “Effects of flame propagation direction on SI engine combustion and exhaut emission” The 9th internal combustion engine symposium Japan 1991
- Khalighi Bahram et. al “Intake-generated swirl and tumble motion in a 4-valve engine with various intake configurations - floaw visualization and particle tracking velocimetry” SAE paper no. 900059 1990
- Reuss David L. et. al “Instantaneous planer measurements of velocity and large-scale vorticity ans strain-rate in an engine using particle-image velocimetry” SAE paper no. 890616 1989
- Fraser R. A. et. al “Cycle-resolved LDV integral length scale measurements investigating clearnce height scaling, isotropy, and homogenity in an I.C. engine” SAE paper no. 890615 1989
- Kudou Hidetoshi et. al “LDV measurement of in-cylinder flow field including vertical vortex” Transaction of the society of automotive engineering of Japan 22 3 1991
- Kimura Ichiro et. al “Image processing instrumentation of flow by using correlation technique” Journal of the visualization society of Japan 6 22 1986
- Kimura Haruo et. al “Image processing instrumentation of flow by using correlation technique, correction of erroneous velocity vectors” Journal of the visualization society of japan 7 26 1987
- Okuno Taketoshi et. al “A note on the flow field image measurement by correlation method” Journal of the visualization society of Japan 10 1 1990
- Kono Seiko et. al “A study of direction against swirl in D. I. engines” COMODIA90 1990
- Howorth D. C. et. al “Multidimensional port-and-cylinder flow calculations for two- and four-valve-poercylinder engine:influence of intake configuration in flow structure” SAE paper no. 900257 1990
- Arooumania A. et. al “Tumbling motion:a mechanism for turbulence enhancement in spark-iginition engines” SAE paper no. 900060 1990
- Alkidas A. C. et. al “Combustion and heat transfer studies in a spark-ignited mulitivalve optical engine” SAE paper no. 900353 1990