| 摘要 |
PURPOSE:To measure a flow rate exactly and stably over a wide range from a low flow rate area to a high flow rate area, by specifying the position and the shape of two parallel plates provided at right angles to an air current direction of an air passage. CONSTITUTION:Two parallel plates 2, 3 functioning as vortex generating bodies are provided in an air passage 1 at right angles to an air current direction, and hot wires 9, 10 are placed on the downstream. When the width of the parallel plates 2, 3, the thickness of the air current direction, and a gap are denoted as (a), (b) and C, respectively, (a), (b) and C are set to the following conditions. b/a is 0.5<=b1a<=0.9, C/b is 0.2<=C/b<0.3, and when the width of the passage 1 is denoted as L, L/a is 3<=L/a<=4. In this way, a Karman vortex is generated stably, and the flow rate can be measured exactly and stably over an area of 100-20,000 Reynolds number. |
