ANALYSIS OF CORONA FROM WATER DROPS PASSING IN POSITVE ROD-TO-PLANE GAPS.

The deformation of a water drop passing in the nonuniform field of a positive rod-plane gap is analyzed. The so-called ″two-spheroidal approximation″ is introduced as a mathematical model for such analysis. Agreement between the calculated and photographed shapes of the deformed drop is satisfactory. A semiempirical criterion is suggested to express the condition of corona threshold from water drops being disintegrated along the gap axis. A satisfactory agreement between the calculated and measured values of threshold voltage was observed. The smaller the drop size, the greater the threshold voltage and the lower the rate of disintegration. The present analysis confirms that the corona threshold in nonuniform fields takes place simultaneously with the disintegration of the drop, the same as for uniform fields.