Experimental study on turbulent characteristics of flow over sand rippled bed*

In this paper the turbulent characteristics of flow in the open channel with a rippled bed were measured systematically in laboratory flume with an acoustic Doppler velocimeter (ADV) and observed by flow visualization with water dyeing. Based on the high-frequency turbulence signal collected, statistic parameters of turbulent characteristics of the open channel flow were calculated, compared and analyzed, the results of which reveals the significant influence of sand ripple on turbulent structure of flow over it.