CHARACTERISTICS OF COMPOUND OPEN CHANNEL FLOW DUE TO SUCTION OPERATION AT THE TIP OF FLOOD PLAIN

Abstract

 In this study, the characteristics of the flow field associated with the suction operation in a compound open channel with a suction operation at the tip of flood plain are investigated by measuring the flow velocity and visualization. The fluorescent dye injection method was used for flow visualization, and PTV was used for flow velocity measurement. From the flow visualization, it was found that the spatiotemporal concentration at the tip of the flood plain of the longitudinal vortex structure was changed to intermittent formation by the suction operation. In the average flow velocity distribution, it was clarified that the oblique upward flow disappeared by the suction operation, and the swirling flow paired in the clockwise direction and the unti-clockwise direction also disappeared. In the turbulence intensity distribution, it was found that the value with suction operation was lower than that with no suction operation. In the Reynolds stress distribution, it was clarified that the phase of the distribution is reversed depending on the presence or absence of suction operation. It was speculated that the intermittentness of this longitudinal vortex structure was the cause of the change in the flow field.