Fuel Technology Applied to Diesel Engines
GTA has discovered that adding of a small amount of a high molecular weight polymer to diesel fuel increases engine power, reduces fuel consumption, reduces engine exhaust temperature and reduces emissions of particulate matter.
It is well known that diesel engine combustion behavior can be improved by improving air/fuel mixture formation. Some improvements have been made by mechanical fixes, such as increased injection pressure, multiple injector orifices and modifications of combustion chamber geometry.
GTA Fuel Enhancer mixture formation by modifying the fuel rather than the engine. A small amount of a high molecular weight polymer is added to the fuel making it viscoelastic. At rest the fuel behaves like an ordinary liquid. Under conditions of sudden stress, however, as in being sprayed from an injector, the fuel has greatly increased viscosity or solid like elastic properties.
A viscoelastic fuel has different spray and vaporization behavior. The injector spray is more controlled producing more uniform droplet size and more uniform distribution of fuel over the cross section of the spray cone. Super fine, satellite droplets are eliminated and overall Sauter Mean Diameter is reduced. The solid like fuel droplets also resist growth by collision.
The vaporization of viscoelastic fuel droplets is also more controlled. Increased surface tension holds in light end fuel components which would otherwise vaporize, leaving the less volatile components behind.
The benefits gained from changes in spray and vapor behavior are in fuel jet penetration and dispersion and in homogeneity of light and heavy fuel species in the air/fuel mixture, each essential to ideal mixture formation. Increased spray penetration and improved dispersion are achieved by having more uniform droplet size, more uniform droplet distribution and reduced droplet growth by collision. The result is a more homogeneous air/fuel equivalency ratio. Modification of the vaporization behavior so that light and heavy components vaporize uniformly from the surface leads to more homogeneous distribution of fast and slow burning fuel species in the air/fuel mixture.
Improved uniformity of air/fuel equivalency ratio throughout the mixture leads to greater cyclic uniformity. Less understood, but equally important in mixture formation, homogeneous distribution of fuel components leads to lower peak temperatures and faster flame propagation. The light ends which normally dominate and drive initial inflammation are moderated by the slower burning molecules. During flame propagation the normally slow burning molecules are heated and thereby aided in burning by the fast burning light end molecules. Overall, uniformity of the air/fuel mixture results in more uniform and complete combustion of the fuel.
From review of SAE literature it is indicated that the changes in mixture formation caused by making fuel viscoelastic hold the greatest promise for large diesel engines where low running speed and lack of swirl effect make spray behavior more important.
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