Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 07, 2019 - November 08, 2019
This study presents the results of a wind-tunnel experiment on the effects of bar shape on the decay coefficient of the grid turbulence generated by the bars. The present grid bars are set as round bars or square bars following to previous researches. Experimental parameters such as the grid Reynolds number are also set based on previous researchers. Present experimental apparatus consists of a wind-tunnel and a measurement section. A slight diffuser is also used at the downstream end of the measurement section to reduce the exhaust loss. A hot-wire anemometer is used to measure velocity fluctuation of the grid-generated turbulence. The drag coefficient of the turbulence-generating grid is obtained by measuring the static pressure values between upstream and downstream regions of the grid. The mean-fluid acceleration is considered to affect the grid turbulence hardly. A value of the decay coefficient is found to be proportional to the drag coefficient of the turbulence-generating grid.
