Numerical and experimental investigation on longitudinal drift motion of a novel regular tetrahedron closure device in casting process

Abstract

A novel prefabricated rapid closure device is proposed to plug dike breaches through a simplified dam structured by different types of closure devices. The experiments show that, however, the closure device will be affected by the flow of water and moves longitudinally in the process of falling. This would adversely affect the arrangement of the devices and construction of stable dams. Hence, a three-dimensional (3D) calculation model is established based on computational fluid dynamics (CFD) methodology to investigate the displacements, forces and velocities of this kind of closure device in water. Having established the consistency of numerical simulations and the model test data, the device underwater movements are investigated for various water depths, current velocities and device weights. Numerical predictions and model test observations suggest that the longitudinal translation travelled by the closure device nonlinearly goes up with the increment of water depth and current velocity as well as the reduction of device mass. For the closure devices with same penetration depth underwater, its horizontal displacement in shallower water is greater than that in deeper water. For the conditions of water depth greater than 2.5 m, the flow velocity greater than 2 m/s and the device mass less than 2.13 t, the longitudinal drift of plugging device cannot be underrated.