Burning rates or evaporation rates of fuel drops have been calculated for spherical geometry (see for example F.A. Williams' book "Combustion Theory", 1985, 2nd. Ed. p. 47), by a combination of theoretical and experimental techniques. These estimates have been used to approximate evaporation rates for curved surfaces, e.g. Lian and Reitz (1993), by approximating by the local curvature of the surface. But is there any more accurate way to calculate this evaporation rates either from a theoretical or experimental source?