JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.23, sa.3, ss.637-644, 2008 (SCI-Expanded)
In this study, the effects of the longitudinal-groove roughness elements (placed on the outer surface of the pipe) on the drag force acting on the pipe were experimentally investigated and compared with uniform sand roughness. The experimental results have indicated that the drag force exerted by the flow on a pipe increases as the distance between the canal bottom and the pipe and the height of roughness elements increases and it decreases as the distance between two successive longitudinal-groove roughness elements decreases. The experiments have also shown that there is some difference between the drag forces corresponding to longitudinal-grove roughness elements and uniform sand roughness elements for the same height.