Full-bore crank-angle resolved imaging of combustion in a four-stroke gasoline direct injection engine

The conventional Bowditch piston arrangement in an optical access engine limits the field of view to about half the bore area. By using a transparent crown (with a flat top) and incorporating a concave surface into the underside of the piston, then the piston crown acts as a diverging lens. Appropri...

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Main Authors: Ma, H, Marshall, S, Stevens, R, Stone, R
Format: Journal article
Sprog:English
Udgivet: 2007
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author Ma, H
Marshall, S
Stevens, R
Stone, R
author_facet Ma, H
Marshall, S
Stevens, R
Stone, R
author_sort Ma, H
collection OXFORD
description The conventional Bowditch piston arrangement in an optical access engine limits the field of view to about half the bore area. By using a transparent crown (with a flat top) and incorporating a concave surface into the underside of the piston, then the piston crown acts as a diverging lens. Appropriate choice of the radius of curvature and the piston crown thickness provides an image of the full bore. There is of course optical distortion in the image but, since the piston position is known for each image, then it is comparatively simple to reconstruct undistorted images and videos. As an illustration of the technique, results are presented here for flame front tracking, and estimates of the combustion temperature and soot loading by a colour ratio pyrometry technique. This full-bore imaging technique is also applicable to many other optical diagnostic techniques. For a motored engine with particle imaging velocimetry and an optical cylinder liner, then the light sheet could enter either through the piston to illuminate a vertical plane or through the cylinder liner and be imaged through the piston. The choice of laser-based combustion diagnostic techniques would be limited by the transmission range of the piston window. © IMechE 2007.
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spelling oxford-uuid:bc0f6ee3-db49-49f1-8bb6-c79bda8886b82022-03-27T05:21:36ZFull-bore crank-angle resolved imaging of combustion in a four-stroke gasoline direct injection engineJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bc0f6ee3-db49-49f1-8bb6-c79bda8886b8EnglishSymplectic Elements at Oxford2007Ma, HMarshall, SStevens, RStone, RThe conventional Bowditch piston arrangement in an optical access engine limits the field of view to about half the bore area. By using a transparent crown (with a flat top) and incorporating a concave surface into the underside of the piston, then the piston crown acts as a diverging lens. Appropriate choice of the radius of curvature and the piston crown thickness provides an image of the full bore. There is of course optical distortion in the image but, since the piston position is known for each image, then it is comparatively simple to reconstruct undistorted images and videos. As an illustration of the technique, results are presented here for flame front tracking, and estimates of the combustion temperature and soot loading by a colour ratio pyrometry technique. This full-bore imaging technique is also applicable to many other optical diagnostic techniques. For a motored engine with particle imaging velocimetry and an optical cylinder liner, then the light sheet could enter either through the piston to illuminate a vertical plane or through the cylinder liner and be imaged through the piston. The choice of laser-based combustion diagnostic techniques would be limited by the transmission range of the piston window. © IMechE 2007.
spellingShingle Ma, H
Marshall, S
Stevens, R
Stone, R
Full-bore crank-angle resolved imaging of combustion in a four-stroke gasoline direct injection engine
title Full-bore crank-angle resolved imaging of combustion in a four-stroke gasoline direct injection engine
title_full Full-bore crank-angle resolved imaging of combustion in a four-stroke gasoline direct injection engine
title_fullStr Full-bore crank-angle resolved imaging of combustion in a four-stroke gasoline direct injection engine
title_full_unstemmed Full-bore crank-angle resolved imaging of combustion in a four-stroke gasoline direct injection engine
title_short Full-bore crank-angle resolved imaging of combustion in a four-stroke gasoline direct injection engine
title_sort full bore crank angle resolved imaging of combustion in a four stroke gasoline direct injection engine
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AT marshalls fullborecrankangleresolvedimagingofcombustioninafourstrokegasolinedirectinjectionengine
AT stevensr fullborecrankangleresolvedimagingofcombustioninafourstrokegasolinedirectinjectionengine
AT stoner fullborecrankangleresolvedimagingofcombustioninafourstrokegasolinedirectinjectionengine