2021 年 56 巻 5 号 p. 241-250
Experimental cylinders were produced, cooling by fins with slits of various widths, all with the slits arranged 30° apart around the edge of the fin, and with slits offset at a phase difference of 15° to the slits immediately above. This study investigated the effect of offset slit width on cylinder cooling. These experimental cylinders were installed in a wind tunnel, where the heat transfer rate from the cylinders was measured, and the air flow between the fins as well as over the fin surface was observed. Results indicated that, compared to a conventional finned cylinder without slits, these finned cylinders with offset slits increased cylinder cooling. In these cylinders, cylinder cooling increased as the slit width increased to 12 mm. Then cylinder cooling decreased as the slit width exceeded 12 mm. Thus the cylinder with the best cooling had offset slits with a slit width of 12 mm. This cylinder tended to cool better than the best cylinder in our previous study, which had aligned slits with a width of 14 mm.