Measurement of local mass transfer on a surface in the region of the base of a protruding cylinder with a computer-controlled data acquisition system

A computer-controlled, automated data-acquisition system is employed to investigate the mass transfer characteristics of a subliming flat naphthalene surface on which a protruding cylinder is mounted with its axis perpendicular to the surface. Two cylinders with different height to diameter ratios (1 and 12) are studied. The experiments indicate that cylinder height influences the local mass transfer distribution in the region downstream of cylinder while it has little effect upstream. The average mass transfer rate over the entire measurement domain is about 8% higher with the shorter cylinder as compared to the taller one. The measurements demonstrate the automated system can provide good experimental accuracy and operating convenience.