A wind tunnel and theoretical study on the melting behavior of atmospheric ice particles. II:a theoretical study for frozen drops of radius < 500 micron

The internal and external heat transfer of a melting spherical ice particles less than 500 ?m radius has been investigated theoretically. The effect of an internal circulation and eccentric location of the ice core was modeled. These two effects combined to reduce total melting times by 10%. However, this still left a 10-15% difference between theoretical and experimental melting times which could not be explained by experimental error. The external heat transfer was subsequently investigated, and it is postulated that: 1) surface irregularities and nonsphericity, 2) rear eddy shedding, and 3) nonsteady motions, are able to increase the external ventilation coefficient by a factor of two, and thus account for the observed discrepancy in melting times.