| 摘要 |
PURPOSE:To enable the experiment to be performed under the conditions very similar to the natural conditions, by arranging an inner tube whose opening is expanded toward the upstream side in the inside of a stream constricting part, connecting the end of the inner tube at the downstream side, thererby reducing the wind distribution at the measuring part of the wind tunnel. CONSTITUTION:When the temperature difference occurs between the upper part and the lower part of a wind guiding tube part 2 due to some causes such as the effect of sunlight and ambient temperatures, the temperature difference also occurs in the wind flow in the inside. When the temperature at the upper part is high and the temperature at the lower part is low, the upper part of the tunnel is usually accelerated. Difference also occurs in the temperatures of the wind in the measuring part 7, which are measured by a pair of temperature sensors 14a and 14b. The output of the upper sensor 14a becomes large and the output of 14b becomes small. Based on the output difference between the sensors 14a and 14b, a controller 15 increases the number of rotation of an upper exhaust fan 13a in order to increase the amount of exhaustion, decreases the number of rotation of a lower exhaust fan 13b in order to decrease the amount of exhaussion. Thus the uniform wind distribution illustrated by a solid line can be obtained. |
