Evaporation histories of fuel sprays injected across a flowing air stream

For systems featuring cross-stream injection of fuel into flowing air, a calculation procedure is presented which allows the fraction of fuel evaporated to be estimated rapidly as a function of downstream distance from the plane of fuel injection. The method takes into account the effects on evaporation length of variations in ambient air pressure, temperature, and velocity, as well as changes in fuel spray characteristics such as mean drop size and drop-size distribution. Calculations carried out at typical gas turbine combustor operating conditions indicate that the main factors influencing the length required to achieve any given degree of fuel evaporation are air temperature and velocity, and the mean drop size of the spray.