1. ME 475/675 Introduction to Combustion Lecture 12 Droplet evaporation, Example 3.2

2. Announcements HW 4 due Now Midterm 1 September 28, 2015, 8-10 AM, PE 104 Review Friday, September 25 HW 5 Due Friday, September 25, 2015

3. Droplet Spherical Evaporation

6. Example 3.2 (page 99) Turn in next time for EC In mass-diffusion-controlled evaporation of a fuel droplet, the droplet surface temperature is an important parameter. Estimate the droplet lifetime of a 100-  m-diameter n-dodecane droplet evaporating in dry nitrogen at 1 atm if the droplet temperature is 10 K below the dodecane boiling point. Repeat the calculation for a temperature 20 K below the boiling point, and compare the results. For simplicity, assume that, in both cases, the mean gas density is that of nitrogen at a mean temperature of 800 K. Use this same temperature to estimate the fuel vapor diffusivity. The density of liquid dodecane is 749 kg/m 3. Find:___ Given:___

7. Liquid-Vapor Interface Boundary Condition A+B Vapor Liquid A

9. Stefan Problem Mass Flux of evaporating liquid A