Author(s): Xiaofeng Liu
Linked Author(s):
Keywords: Scour protection; Sediment transport; CFD; Immersed boundary method
Abstract: Scour protections with ripraps are porous which allows turbulent flow penetration. One of the consequences of the penetrating turbulent flow is the possible erosion of fine particles blow the scour protection. The gradual removal of sediment from the base could cause dislodge and sinkage of riprap rocks which could eventually lead to the failure of the scour protection. To fully understand this penetration-erosion-failure process and for better design, it is important to quantify the flow field inside the scour protection. In previous work, we have approximated the riprap rocks as spheres with similar sizes. In this paper, a novel method toward physical and realistic simulations with real rocks is presented. Riprap rocks are digitized using a 3D laser scanner. These rocks were randomly selected. Collision detection and rigid body dynamics algorithms are then used to mimic the rock dumping process. The resulting spatial arrangement of the rocks forming the scour protection is physically correct. When the spatial configuration of riprap particles is available, it is represented in the computational fluid dynamics (CFD) model using a new immersed boundary method (IBM). This approach is only feasible for limited number of large particles. Simulation examples will be given to demonstrate the new method. The strength and weakness of the method will also be discussed.
Year: 2013