907 自己再循環が軸流送風機の性能に与える影響(OS12-(1)オーガナイズドセッション《流体工学・熱流体》)

Abstract

The performance of a single stage axial-flow fan with a perforated casing wall was experimentally investigated with a view to improving the stall margin at off-design flow conditions. The annular rows of holes introduced were located midway of the rotor passage and in the vicinity of the outlet from the rotor. A self-circulation system by tubing these two rows of holes led to an expansion of the stall margin without any deterioration of design point efficiency. An optimum opening of the perforation was found in which the stall margin was maximized. These results were compared with those of the free bleeding case.