Drop evaporation theory for spherical and ellipsoidal drops

2 Drop evaporation theory for spherical and ellipsoidal drops 

If we want to use a contact angle value in thermodynamic equations, measurement of the initial value of a contact angle, 0 , at the instance of drop formation is required. Determi- 

After differentation, Equation (659) can be reduced to the angular function, F(9) on one side and the diffusion parameters on the other side 

The angular function fits a straight line in a F(9) versus 9 plot, over the range 30-90° according to the expression [F(9) = -1.592 + 1.6320], where 0is in radians. 

Mathematical expressions for an ellipsoidal cap drop resting on a solid surface having three parameters (base radius, height and contact angle) were subsequently also derived, and this model fitted the experimental data better than those evaluated from the spherical 

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