論文ID: 2019.2856
Experimental air-cooled cylinders were produced with slits of various widths cut into their fins. The slits were arranged in an equiangular 30° spiral around the circumference. These finned cylinders were installed in a wind tunnel, with the cylinder axis perpendicular to the air flow, at two different rotations: one oriented so that the center of the fin slit in one row was located directly in front of the air flow, and another rotated 15° around the circumference from that orientation,so no slit was located directly at the front. Heat transfer rate from the cylinder was measured at air velocities between 20 km/h (5.6 m/s) and 60 km/h (16.7 m/s). The air flow between fins was observed using the smoke wire method, and the air flow over the fin surface was observed using the oil film method. Results indicated that, compared with a conventional finned cylinder lacking slits, our finned cylinder with slits increased cylinder cooling. In both slit orientations to the air flow, cylinder cooling increased with increased slit width, up to a point. When the slit width became too wide, cylinder cooling decreased. Furthermore, cylinder cooling increased when the slits were turned away from the air flow, rather than oriented directly in front of the flow.