A theoretical study of the spheroidal droplet evaporation in forced convection

• Fully algebraic solutions for the spheroidal droplet evaporation rate is obtained.
• We examine the effect of aspect ratio on the droplet evaporation.
• We propose a calculation method of Nusselt number for spheroidal droplet.

In many applications, the shape of a droplet may be assumed to be an oblate spheroid. A theoretical study is conducted on the evaporation of an oblate spheroidal droplet under forced convection conditions. Closed-form analytical expressions of the mass evaporation rate for an oblate spheroid are derived, in the regime of controlled mass-transfer and heat-transfer, respectively. The variation of droplet size during the evaporation process is presented in the regime of shrinking dynamic model. Comparing with the droplets having the same surface area, an increase in the aspect ratio enhances the mass evaporation rate and prolongs the burnout time.