| 摘要 |
PURPOSE:To attain effect rectification in a small space to attain the precise measurement of liquid by limiting the ratio of the thickness of a flow straightener on the upper side in the flow direction of a flow straightening element to a cell size within a prescribed range. CONSTITUTION:Suction air is made to flow into a flow straightener 6, a vortex generator 5, a rectifier 7, a slottle valve 4, and an engine body 1 successively. The vortex generator 5 generates a Karman's vortex at a period proportional to the flow rate of the suction air. Thereby, the flow rate of the suction air can be measured by detecting the generating period or frequency of the Karman's vortex by a heat wire or a vortex detector. Since the flow straightening effect is suddenly reduced if the ratio D/W of the thickness D of the flowstraightening element of the cell size in the suction air flow meter is dropped less than 3, it is practically preferable to keep the ratio D/W at about 2.5 or more. Therefore, an effective result can be obtained in pressure loss by selecting a value more than 2.5 as small as possible under the consideration of the effective utilization of a space. |
