In the present study, a method to scan the front face toward a scanner of measured objects behind an obstacle around a scanner by a two-dimensional laser range scanner and mirrors is described. Distances and angles from the scanner to the measured objects through the mirrors to avoid the obstacle at a constant angle are measured radially by laser. Laser reflecting points on the front face of the measured objects behind the obstacle at a constant angle are gotten. A construction and a function about the suggested scan method using the scanner and the mirrors are shown. Coordinate systems are set to design the suggested scan method based on the construction and the function. Coordinates and angles of the obstacle and the mirrors, trajectories of the laser, installation of the scanner and the mirrors, and coordinates of the laser reflecting points on the front face of the measured objects are designed based on the coordinate systems. An experimental equipment was designed as described above to evaluate a performance of the suggested scan method. The experimental equipment was built using an actual scanner and mirrors. Experimental methodologies using the experimental equipment were set. Experimental results using the experimental methodologies were considered.
We produced experimental cylinders cooled by fins with various widths of slits, 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, and investigated the effect of slit width on cylinder cooling. We installed these experimental cylinders in a wind tunnel, measured the heat transfer rate from the cylinders, and observed the air flow between the fins as well as over the fin surface. Results indicated that, compared to a conventional finned cylinder without slits, our finned cylinders with offset slits increased cylinder cooling. In our finned cylinders with offset slits, 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 with offset slits with a slit width of 12 mm tended to cool than the best cylinder in our previous study, which had aligned slits with a width of 14 mm.