An exact solution of the mass transport equations for spheroidal evaporating drops

The evaporation rate, the surface vapour flux, the vapour and temperature distribution around a spheroidal drop under steady-state conditions are predicted by means of an exact solution of the species and energy transport equations in spheroidal coordinate systems. The effect of deviation from spherical shape on mass transfer can be calculated, for oblate and prolate drops, by a simple equation that generalises the well known results for spherical drops. A direct dependence of the local vapour flux on the surface Gaussian curvature is evidenced.