الفهرس 
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Abstract
ABSTRACT
An investigation has been carried out to study the effect of changing the inductionmanifoldangleintumbleinducedturbulenceandpistoncombustionchambershape( bowl in piston) squish motion on detonation and pre-ignition in spark ignitionengines with different blends of jojoba bio-gasoline such blends are ( 5%, 10%, 25%and 50%) with normal gasoline (RON80). A Ricardo E6/MS variable compressionresearch engine was used for this purpose. A new cylinder head was designed andmanufacturedforthisenginetoaccommodatedifferentanglesfortheinductionmanifold.The inductionmanifold anglewasused40 o these anglewasmeasuredfromthe horizontalline that isperpendiculartotheaxisofthe liner.
To induce controlled pre-ignition, a pre-igniter was developed to produce an artificialhotspotinsidethecombustionchamber.Suchpre-igniterisinfactadevelopmentofa glowplug.
The onset of pre-ignition and detonation were characterized by the onset of pressureoscillationsinthepressure-crankanglediagraminthebeginningandendofcombustionrespectively.Forthisreason,awater-cooledpiezo-electricpressuretransducer as well as magnetic sensors was used to monitor such oscillations on anOscilloscope screen. Detonation was induced by raising the compression ratio of theengine while it was running till the knock waves appear on the screen; thus, it wascharacterized by the knock-limited compression ratio (KLCR). However, pre-ignitionwas characterized by the input electrical power (PII) consumed by the pre-igniter atthe moment pre-ignition appears on the oscilloscope. Hence, higher input powerindicatedhigherpre-ignition resistance andvice versa.
A set of experiments were carried out on each blends of jojoba bio-gasolinewithnormal gasoline tocover the effect of the design and operating parameters of theengine on detonation and pre-ignition, e.g. engine load, speed, equivalence ratio,compressionratio,inletairtemperatureandignitiontiming.Theexperimentsrevealed that the pre-ignition and detonation tendency increase with the increase ofjojoba bio-gasoline blends andengine load, compression ratio, inlet air temperature,advancing theignition timingandlowering theengine speed.
All the experimental data were used to develop analytical correlations to enable aprediction to be made for use in the design stage. Such correlations which proved topredict thedata well.