The effect of fuel volatility on droplet depletion rate and penetration of vaporizing fuel droplets in a gas turbine combustor

It is well recognized that the fuel volatility has significant role in the dispersion and penetration of the fuel droplets sprayed into a combustor. Hence a study of the fuel droplet penetration and vaporization histories of a liquid fuel spray injected into a turbulent swirling flow of air through a typical can type Gas Turbine Combustor have been evaluated from numerical solutions of the conservation equations in gas and droplet phases. It is observed from the study that generally a higher swirl decrease the droplet penetration rate irrespective of the fuel volatility, but the effect is more pronounced for lighter droplet particles of n hexane than for the heavier kerosene droplets. Also an increase in spray cone angle shows a drastic reduction in the penetration of the spray. The effect of fuel volatility is marginal for different Spray cone angles as the droplet penetration is dictated more by the spray dynamics due to changed spray cone angle than the fuel volatility. But an increase in combustor pressure reduces the droplet penetration considerably. The fuel droplets with higher volatility seem to travel longer in a higher ambience more due to decreased rate of vaporization at higher pressure.