Comparison between numerical analysis and the levitation mass method measurement test of a spherical structure early impacting water

Abstract

In order to precisely measure water impact loads of a spherical structure vertically dropping onto a calm water surface, a new validity check of the analysis using the levitation mass method experiment is proposed. The main feature of levitation mass method experiment is to obtain a better estimation of early water impact loads through the application of Doppler effect. Experimental results of different heights are verified based on the Assessment Index and are in comparison with the classical experimental data for validation purpose. It shows that the levitation mass method measurement is useful and effective to obtain the water impact loads for the crashworthiness analysis. Besides, early water impact hydrodynamic behaviors are simulated based on the nonlinear explicit finite element method, together with application of a multi-material arbitrary Lagrangian-Eulerian solver. A penalty coupling algorithm is utilized to realize fluid-structure interaction between the spherical body and fluids. Convergence studies are performed to construct the proper finite element model by the comparison with experimental results, where mesh sensitivity, contact stiffness, and time-step size parametric studies are thoroughly investigated. The comparisons between experimental and numerical results show good consistency by the prediction of the water impact coefficients on the structure.

Optimization of a land vehicle suspension subjected to a buried charge explosion

“…The penalty coupling behaves like a spring-damping system and the magnitude of this penalty force is calculated proportionally to the penetration, penetration rate and spring stiffness. 53 The leakage control parameters have been chosen so that there is no leakage of the fluid through the structure.…”

Experimental Study on the Mitigation Effect of Polyurethane Foam Densities on the Cylindrical Objects Entering Water at High Velocity

“…The polyurethane material model with the same density as the test was used for simulation. Key parameters [11][12][13] are shown in table 1. Polymer density is 1.2 g/cm 3 , E is young's modulus, P0 is atmospheric pressure, ∅ is the ratio of foam density and polymer density, γ0 is the initial volume strain of foam, which is general 0.…”

Surveying the effects of concave obstacles with different edge walls on hollow glycerin droplet impacting using the volume of fluid approach

“…5 Scientists experimented to see how a hollow droplet interacts with the surface and the morphology of its behaviors. 6 Scientists computed the solidification of hollow droplets on the surface at varied impact velocities and shell thicknesses. 7 The influence of glycerin and diesel hollow droplets with varied dynamic contact angles was numerically simulated by the researcher.…”