直円管内における円形薄板上流の特性

概要

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Until now only one of the research projects by the present authors has dealt with the special properties of laminar water flow in a straight circular pipe, but the present paper is dedicated to an inverstigation of the upper flow passing over a thin discus-shaped plate. The maximum velocity of the flow in the upper part of the pipe was experimentally inverstigated after placing a thin discus-shaped plate inside a straight circular pipe. Investigation of the relation of the maximum flow velocity and the distance of the upper flow from the obstacle was accomplished by employment of an LDV for measuring flow velocity. Experimentation was carried out on the laminar water flows within the low Reynolds number rang. The maximum velocity of the flow varied with distance of the plate; the maximum flow velocity decreased as the flow approached the plate. It would be appropriate to call the extent in which the flow velocity is affected by the plate the retroac-tive length. An experimental equation has been presented to describe the relation between change in the maximum flow velocity and the distance from the obstacle. This equation resembles the equation for the laminar flow inlet length. In conjunction with the above experiment the hydrogen bubble method was also used to perform a flow visualization experiment.
明治大学の論文