2024 Volume 80 Issue 16 Article ID: 23-16168
In this study, the characteristics of the flow field associated with the suction operation of the longitudinal ridge element in an open channel with the longitudinal ridge element installed on the bottom wall were investigated by flow velocity measurement and flow visualization. From the flow velocity measurement results, it was clarified that the remarkable upward flow and paired swirling flow disappeared by the suction operation, and the primary velocity distribution on the longitudinal ridge element became uniform in the transverse direction. In addition, the horizontal Reynolds stress (-uw) is reduced by the suction operation, and the positive and negative phases of the distribution are reversed. Furthermore, in the horizontal turbulence energy generation term (-uw(dU/dy)) distribution, it was clarified that a suction operation produces a negative value on the longitudinal ridge element. It is speculated that the characteristics of the above flow velocity measurement results are caused by the intermittent and small-scale longutudinal vortex structure on the longitudinal ridge element due to the suction operation.
