Surface flow pattern and local mass transfer on the free-end surface of a finite circular cylinder

Relation between the surface flow pattern and the local mass transfer chara cteristic on the free end surface of a finite circular cylinder mounted on a flat plate was investigated using the oil surface flow visualization and the naphthalene sublimation technique. The aspect ratio [the ratio of the c ylinder length to the cylinder diameter (HID)] was 1.25 and the Reynolds nu mber based on the diameter was 1.48 X 10(5). Several kinds of critical poin ts on the free-end surface were identified by the visualization and the mas s transfer measurement around those critical points through the naphthalene sublimation technique was then performed to investigate the relation betwe en the flow and mass transfer. The free-end surface flow was topologically characterized by the presence of a saddle point and two focal points in the fore-half portion of the surface and two nodes and a saddle point in the r ear-half portion. It was found that the rate of mass transfer was largest i n the vicinity of the nodes in the rear-half of the free-end surface.