The maximum compression pressure position relative to top dead centre as an indication of engine cylinder condition and blowby

Kouremenos, DA; Rakopoulos, CD; Hountalas, DT; Kouremenos, AD

dc.contributor.author	Kouremenos, DA	en
dc.contributor.author	Rakopoulos, CD	en
dc.contributor.author	Hountalas, DT	en
dc.contributor.author	Kouremenos, AD	en
dc.date.accessioned	2014-03-01T01:10:21Z
dc.date.available	2014-03-01T01:10:21Z
dc.date.issued	1994	en
dc.identifier.issn	0196-8904	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/11383
dc.subject	Blowby	en
dc.subject	Compression ratio	en
dc.subject	Cylinder condition	en
dc.subject	Top dead centre	en
dc.subject.classification	Thermodynamics	en
dc.subject.classification	Energy & Fuels	en
dc.subject.classification	Mechanics	en
dc.subject.classification	Physics, Nuclear	en
dc.subject.other	Diesel engines	en
dc.subject.other	Heat losses	en
dc.subject.other	Mathematical models	en
dc.subject.other	Position measurement	en
dc.subject.other	Pressure measurement	en
dc.subject.other	Wear of materials	en
dc.subject.other	Blowby	en
dc.subject.other	Compression ratio	en
dc.subject.other	Maximum compression pressure position	en
dc.subject.other	Top dead center (TDC)	en
dc.subject.other	Engine cylinders	en
dc.title	The maximum compression pressure position relative to top dead centre as an indication of engine cylinder condition and blowby	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/0196-8904(94)90035-3	en
heal.identifier.secondary	http://dx.doi.org/10.1016/0196-8904(94)90035-3	en
heal.language	English	en
heal.publicationDate	1994	en
heal.abstract	The compression curve of a DI (Direct Injection) diesel engine is affected by various parameters, such as heat loss, initial temperature and pressure, speed, compression ratio and blowby. Usually the engineer makes use of the measured motored pressure diagram and especially of the maximum compression pressure value to determine the engine condition (wear). However, in order to have an accurate indication of the engine condition, one must consider accurately all the previous mechanisms. This poses a very difficult task since, for example, not even the compression ratio is usually accurately known for an operating engine. Thus, a low maximum compression pressure value may not be caused by increased blowby rate, and so this may lead to a wrong indication of cylinder condition. The present work introduces a new method for determining cylinder condition (wear) and especially the blowby rate. The method is based on the determination of the position of the maximum compression pressure value relative to the TDC (Top Dead Centre) position. The maximum pressure position (before TDC) varies greatly with blowby rate, but is practically unaffected by heat losses, initial temperature and pressure and compression ratio. Experiments have been conducted on a Ricardo E-6, DI diesel engine for various compression ratios, engine speeds and operating temperatures (cold and warm operation) under motoring conditions. Pressure has been measured using a time step equivalent to 0.1-degree-CA, while the TDC position has been determined using a magnetic pickup device. A mathematical simulation accounting for heat losses and blowby has been used to examine the effect of various parameters on maximum compression pressure and its position relative to TDC. The results from both experiments and simulation are found to be in good agreement concerning pressure curves, maximum pressure position and their variation with the parameters examined. The results are promising, showing a high potential for determining any cylinder condition by processing the corresponding measured pressure diagram.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	Energy Conversion and Management	en
dc.identifier.doi	10.1016/0196-8904(94)90035-3	en
dc.identifier.isi	ISI:A1994PF37900004	en
dc.identifier.volume	35	en
dc.identifier.issue	10	en
dc.identifier.spage	857	en
dc.identifier.epage	870	en