Erosion occuring on the clay mixture base under the effect of propeller jet flow

Objective: In this study, the scour problem on the seabed under the effect of propeller jets was investigated at the cohesive base and the test results were compared with the scour depths on the cohesionless base. Materials and Methods: In the study, a laboratory tank with a length of 3.2 m, a width of 1.5 m and a height of 1 m was constructed. Cohesionless quartz sand and cohesive kaolinite clay were used to simulate the seabed. In the experiment, the propeller height (G) and propeller diameter (Dp) were chosen as 0.06m. In the experiments, the scour depths were measured with an Acoustic Doppler Velocimeter (ADVP). Results: This study consists of 3 main parts. Firstly, the scour behavior of the cohesionless sand base and then the clay-sand mixture base containing 5% and 10% clay were investigated. At the end of the experiment, only sand base and mixed base profiles containing different percentages of clay were compared. It was concluded that as the clay ratio increased, the scour depth decreased. Conclusion: The scour depth was significantly reduced when different proportions of clay were added to the base, and in some cases no secondary scour was formed. It was determined that there was a decrease of approximately half the scour depth of the experiments containing sand and 10% clay Key Words: Clay-sand mixture, Cohesive material, Propeller jet, Scouring