Unsteady cavitation around submerged and water-exit projectiles under the effect of the free surface: A numerical study

Nguyen, Van-Tu; Phan, Thanh-Hoang; Duy, Trong-Nguyen; Park, Warn-Gyu

doi:10.1016/j.oceaneng.2022.112368

Cited by 17 publications

(2 citation statements)

References 26 publications

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“…Bhalla et al [15] employed the fictitious domain method to simulate the water exit problem for a free-falling wedge and cylinder. Nguyen et al [16] used the Navier-Stokes model for three-phase flows and studied the exit process of projectiles and the collapse of a cavity containing entrained water under the effect of the free surface. Moshari et al [17] developed a finite volume discretization to determine the nonlinear free surface deformation during the water exit of a circular cylinder, while Murea et al [18] solved a dynamic fluidstructure problem using the Navier-Stokes equations to compute the free surface force.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Investigation of Cavity Structure Forced Water Exit from Calm Water at Constant Lifting Velocity

Zan

Ding

et al. 2023

JMSE

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In marine engineering, the installation of structures inevitably involves the process of water exit. This paper studies the vertical force, the shape of the free surface, and the evolution of the water entrained in a cavity in the process of lifting a structure, so as to provide guidance for practical engineering operations. Using a 1:8 experimental model, this paper derives the governing equations based on the Reynolds-averaged Navier–Stokes approach and uses the volume of fluid method to capture the shape change of the free surface. The vertical forces obtained at different lifting speeds are found to be in good agreement with the results of previous model tests. The results show that the numerical simulation method and mesh generation described in this paper can simulate the changes in the physical quantities associated with the structure in the process of water exit. The vertical force on the structure increases nonlinearly as the lifting speed rises, and the maximum lifting speed is conservatively estimated to be 0.034 m/s using the Det Norske Veritas recommended method. The maximum vertical force occurs as the whole structure leaves the water. The water entrained in the structure is mainly located at the sides and bottom. The lifting velocity plays an important role in the water exit process. The water exit force first increases and then decreases to a stable value as the lifting velocity increases, while the maximum water exit force increases nonlinearly.

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Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Investigation of Cavity Structure Forced Water Exit from Calm Water at Constant Lifting Velocity

Zan

Ding

et al. 2023

JMSE

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“…Zhang et al [11] numerically analyzed the problem of a cylinder exiting water and concluded that collapse of the cavity leads to pressure fluctuations on the wall of the cylinder as well as in the surrounding water. Nguyen et al [12] conducted numerical simulations of the process of a projectile exiting water to examine the characteristics of growth, shedding, and collapse of the cavity under the influence of the free surface. Gao et al [13,14] used a model of the improved, delayed detached eddy simulation (IDDES) to study the structure of cavitation-induced flow, the structure of the vortex on the wall, and the loading characteristics of vehicles during their exit from water, with a focus on analyzing the mechanism of evolution of cavitation-induced flows.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Characteristics of an Underwater Ventilated Vehicle Exiting Water in an Environment with Scattered Ice Floes

Zhang,

Lin,

et al. 2023

JMSE

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The presence of ice floes on the water surface has a significant impact on the complex hydrodynamic process of submersible ventilated vehicles exiting the water. In this paper, we propose numerical simulations based on computational fluid dynamics to investigate the process of a ventilated vehicle exiting water in an ice-water mixture. The Schnerr–Sauer model is used to describe the cavitation, while the turbulence is solved by using the k-ω shear stress transport (SST) model. We also introduce the contact coupling method to simulate the rigid collision between the vehicle and the ice floe. We calculated and analyzed the process of the vehicle exiting the water under three conditions: ice-free conditions and in the presence of regularly shaped and irregularly shaped ice floes. The findings indicate that the ice floes contributed to the rapid fragmentation of the water plume to induce the premature collapse of the ventilated cavity and alter its form of collapse. The presence of ice floes intensified the evolution of the flow field close to the vehicle, and their flipping led to a significant volume of splashing water that could have led to the localized secondary closure of the cavity. Moreover, the collision between the vehicle and the ice floes caused pressure pulsations on the surface of the former, with a more pronounced effect observed on the head compared with the cylindrical section. While crossing the ice-water mixture, the vehicle was exposed to water jets formed by the flipping ice floes, which might have led to localized high pressure.

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Effects of axial launch spacing on cavitation interference and load characteristics during underwater salvo

Gao,

Shi,

et al. 2024

Applied Ocean Research

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Unsteady cavitation around submerged and water-exit projectiles under the effect of the free surface: A numerical study

Cited by 17 publications

References 26 publications

Experimental and Numerical Investigation of Cavity Structure Forced Water Exit from Calm Water at Constant Lifting Velocity

Experimental and Numerical Investigation of Cavity Structure Forced Water Exit from Calm Water at Constant Lifting Velocity

Dynamic Characteristics of an Underwater Ventilated Vehicle Exiting Water in an Environment with Scattered Ice Floes

Effects of axial launch spacing on cavitation interference and load characteristics during underwater salvo

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