Laboratory study of the temporal evolution of channel bed topography in presence of two rows of inclined-vertical piers in a sharp 180-degree bend

Abstract

ABSTRACT This paper is aimed to investigate the temporal variation of scour depths and bed topography in the presence of a group of six vertical and inclined piers placed in a 180-degree bend flume. For this purpose, a series of tests were performed in a test flume provided by Hydraulics Laboratory of Persian Gulf University, Bushehr, Iran. The piers were placed at the angle of 60-degree of the bent flume. The flume was 1 m wide and the ratio of curvature to the width of 2 and has two straight sections at its upstream and downstream with 6.5 m and 5.1 m length, respectively. The results showed the temporal evolution of scour depth was decreased with the passage of time. The location of the maximum scour depth was time dependent so that as the experiment progressed, it moved from the vicinity of the inner bank to the middle of the flume and eventually to the outer bank. Also, the inception of the scour holes near the inner bank and outer bank was different. However, this difference was decreased during the test progress.