THE VELOCITY DISTRIBUTION IN THE INNER FLOW FIELD AROUND A CLOTHED CYLINDER

抄録

The velocity distribution in the inner flow field around a solid cylinder that was covered with a cloth and immersed in an air flow was studied experimentally by hot-wire anemometry. The cicumferential distribution of the velocity was detected by a hot-wire probe which was inserted into the clearance between the inner surface of the covering cloth and the surface of the cylinder. The results suggested that, with being away from the frontal stagnation point, the inner flow was accelerated to a maximum point positioned at about 45 degrees distant along the cylinder circumference from the starting point, and then decelerated to zero velocity at a 90-degree point. It was confirmed that the inner air flow blew off from the inner field in the region between these two positions and that the maximum velocity increased linearly with the permeability of the covering cloth. The effects of doubling the covering and of changing the thickness of the inner flow region were also investigated. It was shown, as the result, that the flow permeation into the inner region could be strongly suppressed by covering doubly, and that increasing the clearance raised the inner flow velocity.