Effect of Gasoline Fuel Additives on Combustion and Engine Performance

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µm
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4.2 Combustion Investigations 
105 
current study while Elkotb’s [142] equation produced droplets over three times the 
size. This is displayed in Figure 4.16.
 
Figure 4.15: Comparison of experimental base fuel droplet size and empirically established 
relationships. All data normalised to maximum droplet size in each data set 
Figure 4.16: Comparison of experimental base fuel droplet size and empirically established 
relationships. Actual values of each data set displayed 
4.2
 
Combustion Investigations 
Combustion investigations were carried out using the equipment described in 
Chapter 3. Three methods for combustion analysis were employed. The combustion 
vessel was used for GDI spray and gasoline vapour combustion while the single 
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1
1.1
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120
SM
D
, µ
m
/µ
m
Pressure, bar
Hiroyasu & Kodota
Knight
Elkotb
Experimental - 50% Transmission
Experimental - Minimum Transmission
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D
, µ
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Pressure, bar
Elkotb
Knight
Hiroyasu & Kodota
Experimental - 50% Transmission
Experimental - Minimum Transmission

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4.2 Combustion Investigations 
106 
cylinder research engine was used to examine the additive effects under engine 
conditions. Throughout the following sections, the base fuel characteristics are 
explained and methodology for the following analysis described. All pressures in this 
chapter and Chapter 6 (analysis of effects of fuel additives on combustion) are 
expressed in terms of gauge pressure, unless explicitly specified.