The effect of surface lobes on heat transfer from an ice particle

AGUIRRE VARELA, GUILLERMO GABRIEL; CASTELLANO, NESVIT; PEREYRA, RODOLFO GUILLERMO; AVILA, ELDO EDGARDO

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY

JOHN WILEY & SONS LTD

Año: 2003 vol. 129 p. 3425 - 3428

0035-9009

The convection heat-transfer coefŽ cient for circular cylinders, exposed to an air stream perpendicular to their axis, is dependent on the Reynolds number, Re. There is experimental evidence showing that the heattransfer coefŽ cient for hail or graupel growing by accretion of supercooled water droplets is greater than that corresponding to an equivalent smooth surface. Work carried out so far indicates that surface roughness could in uence this coefŽ cient. This work presents an experimental study of the in uence of lobes on the heat-transfer process to the surroundings from metallic cylinder surfaces. The dependence of the heat-transfer coefŽ cient on Re was studied for 2000 Re 20 000. Results show that the presence of lobes and lumps on a smooth surface could, in some cases, increase the heat transfer towards the surroundings by ventilation. However, results also show that this is not likely to be the effect responsible for increasing the ventilation coefŽ cient for graupel compared with smooth surfaces.