Numerical Investigation of Water Entry Problem of Pounders with Different Geometric Shapes and Drop Heights for Dynamic Compaction of the Seabed

Abstract

The water entry problem of three-dimensional pounders with different geometric shapes of cube, cylinder, sphere, pyramid, and cone was numerically simulated by the commercial software Abaqus, and the effects of pounder shape and drop height from the free surface of water on deepwater displacement and velocity as well as pinch-off time and depth were investigated. An explicit dynamic analysis method was employed to model fluid-structure interactions using a Coupled Eulerian-Lagrangian (CEL) formulation. The simulation results are verified by showing the computed shape of the air cavity, displacement of sphere, pinch-off time, and depth which all agreed with the experimental results. The results reveal that the drag force of water has the highest and lowest effect on cubical and conical pounders, respectively. Increasing the pounder drop height up to the critical height leads to increased pounder velocity while impacting the model bed and more than the critical drop height has a reverse effect on pounder impact velocity. Pinch-off time is a very weak function of pounder impact velocity; but pinch-off depth increases linearly with increased impact velocity.

Simplified Procedure for Capacity Check of Historic Monolithic Glass Windows under Soft-Body Collision/Bird-Strike

“…The four input parameters for Us-Up EOS, according to Equation ( 5), were set as proposed in References [5,56,[58][59][60]; that, is c 0 = 1480 m/s, s f = 0, and Γ 0 = 0. While the Us-Up EOS is primarily used for shock simulations, studies from the literature proved its applicability (with herein reported input values) also for water-impact configurations under low-velocity collisions [61,62]. Finally, the material density was set as ρ 0 = 938 kg/m 3 .…”

Numerical and experimental investigation on the oblique water entry of cylinder

“…Besides these, the boundary element method, 26 constrained interpolation profile (CIP) method, 27 the arbitrary Lagrange–Euler (ALE) method, 28 , 29 and lattice Boltzmann method (LBM) 30 are all used for numerical simulation of water entry. Coupled Euler–Lagrange (CEL) analysis is another method to deal with the water entry problem, 31 , 32 which is effective and beneficial. Ahmadzadeh et al 33 adopted CEL method to simulate a free-falling sphere impacting the free surface of water.…”

“…In this article, based on the settings of CEL method, 31 – 34 with consideration of the influence of air content in water, an improved CEL method is proposed to simulate water entry of the cylinder. Besides, the water entry experiments of the cylinder are carried out.…”