Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 08, 2021 - November 10, 2021
The effect of roughness pitch ratio for a wall-bounded shear flow has been investigated based on spatial averaging operation of the Reynolds equation for a channel flow. The roughness pitch ratio was PR =1, 2, 4, 8 and 16.The velocity field was measured with 2-D PIV system. The Reynolds number based on the channel height was 2500. The spatially averaged streamwise mean velocity profiles of PR = 4, 8 and 16 were defected compared to those of PR =1 and 2 on a rough wall side. The spatially averaged shear stress profiles for all roughness pitch ratios can be represented as a liner function, and the slope of each linear function varied depending on the local skin friction coefficient. The profile of the spatially averaged Reynolds stresses takes a maximum value at the roughness pitch ratio of 8. The peak value of the dispersive stresses increases with the roughness pitch ratio.
