Effect of surface tension and evaporation on phase change of fuel droplets

A model is developed which describes the phase-change process (evaporation) of fuel droplets in a gas turbine engine combustor: To develop this model we have employed the conservation laws (droplet momentum, heat and mass tra nsfer). Specifically, we used Newton's second la,v of motion in conjunction with the thermal expansion of the droplet. In this study the droplet densi ty is considered to be a function of temperature, rho (p) = rho (p)(T-p). A s a consequence, the thermal expanisvity alpha = -rho (-1)(p)(d rho (p)/dT( p)) is introduced, which has a significant effect on the evaporation proces s. Furthermore, the conditions on the droplet's surface are determined by t aking into account the effect of surface tension on the fuel vapor pressure . The droplet characteristics such as position, velocity, temperature, and diameter are described by a system of sir ordinary differential equations. which are solved numerically using a variable step Runge-Kutta algorithm of order 5(4). Due to the above conditions, our results differ from those rep orted in the literature [1-5].