An improved Kirkwood–Bethe model for calculating near-field shockwave propagation of underwater explosions

Jingxiao Zhang; Shushan Wang; Xiyu Jia; Yuan Gao; Feng Ma

doi:10.1063/5.0040224

Numerical modeling for compressible two-phase flows and application to near-field underwater explosions

Computers & Fluids ◽

10.1016/j.compfluid.2020.104805 ◽

2021 ◽

Vol 215 ◽

pp. 104805

Author(s):

Van-Tu Nguyen ◽

Thanh-Hoang Phan ◽

Trong-Nguyen Duy ◽

Warn-Gyu Park

Keyword(s):

Numerical Modeling ◽

Near Field ◽

Two Phase Flows ◽

Two Phase ◽

Underwater Explosions

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A Framework of Runge–Kutta, Discontinuous Galerkin, Level Set and Direct Ghost Fluid Methods for the Multi-Dimensional Simulation of Underwater Explosions

Fluids ◽

10.3390/fluids7010013 ◽

2021 ◽

Vol 7 (1) ◽

pp. 13

Author(s):

Nan Si ◽

Alan Brown

Keyword(s):

Discontinuous Galerkin ◽

Level Set ◽

Early Stage ◽

Near Field ◽

Early Time ◽

Inviscid Fluid ◽

Rarefaction Waves ◽

Material Interface ◽

Underwater Explosions ◽

Runge Kutta

This work describes the development of a hybrid framework of Runge–Kutta (RK), discontinuous Galerkin (DG), level set (LS) and direct ghost fluid (DGFM) methods for the simulation of near-field and early-time underwater explosions (UNDEX) in early-stage ship design. UNDEX problems provide a series of challenging issues to be solved. The multi-dimensional, multi-phase, compressible and inviscid fluid-governing equations must be solved numerically. The shock front in the solution field must be captured accurately while maintaining the total variation diminishing (TVD) properties. The interface between the explosive gas and water must be tracked without letting the numerical diffusion across the material interface lead to spurious pressure oscillations and thus the failure of the simulation. The non-reflecting boundary condition (NRBC) must effectively absorb the wave and prevent it from reflecting back into the fluid. Furthermore, the CFD solver must have the capability of dealing with fluid–structure interactions (FSI) where both the fluid and structural domains respond with significant deformation. These issues necessitate a hybrid model. In-house CFD solvers (UNDEXVT) are developed to test the applicability of this framework. In this development, code verification and validation are performed. Different methods of implementing non-reflecting boundary conditions (NRBCs) are compared. The simulation results of single and multi-dimensional cases that possess near-field and early-time UNDEX features—such as shock and rarefaction waves in the fluid, the explosion bubble, and the variation of its radius over time—are presented. Continuing research on two-way coupled FSI with large deformation is introduced, and together with a more complete description of the direct ghost fluid method (DGFM) in this framework will be described in subsequent papers.

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Response of Composite Cylinders Subjected to Near Field Underwater Explosions

Dynamic Behavior of Materials, Volume 1 - Conference Proceedings of the Society for Experimental Mechanics Series ◽

10.1007/978-3-319-41132-3_21 ◽

2016 ◽

pp. 153-157 ◽

Cited By ~ 1

Author(s):

E. Gauch ◽

J. LeBlanc ◽

C. Shillings ◽

A. Shukla

Keyword(s):

Near Field ◽

Underwater Explosions ◽

Composite Cylinders

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Protective effect of polymer coating on the circular steel plate response to near-field underwater explosions

Marine Structures ◽

10.1016/j.marstruc.2014.11.005 ◽

2015 ◽

Vol 40 ◽

pp. 247-266 ◽

Cited By ~ 7

Author(s):

Yong Chen ◽

Feng Chen ◽

Zhi Peng Du ◽

Yu Wang ◽

Peng Duo Zhao ◽

...

Keyword(s):

Protective Effect ◽

Polymer Coating ◽

Steel Plate ◽

Near Field ◽

Underwater Explosions

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Near-field scanning optical microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144644 ◽

1986 ◽

Vol 44 ◽

pp. 642-643

Author(s):

E. Betzig ◽

A. Harootunian ◽

M. Isaacson ◽

A. Lewis

Keyword(s):

Near Field ◽

Optical Microscope ◽

Visible Radiation ◽

Field Methods ◽

Optical Elements ◽

Optical Region ◽

Order Of Magnitude ◽

Nondestructive Imaging ◽

Scanning Optical Microscopy ◽

Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

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