Tuning control parameters of underwater vehicle to minimize the influence of internal solitary waves

Ocean Engineering, Journal Year: 2024, Volume and Issue: 310, P. 118681 - 118681

Published: July 10, 2024

Language: Английский

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Numerical investigation on the interaction between internal solitary wave and self-propelled submersible

Physics of Fluids, Journal Year: 2023, Volume and Issue: 35(10)

Published: Oct. 1, 2023

Internal solitary waves (ISWs) often seriously threaten the survivability of underwater submersible. Most existing investigations focus on interaction between ISWs and fixed or suspended submersibles. However, investigation self-propelled submersibles is still scarce, which a more realistic case in marine engineering. In this paper, three-dimensional numerical model for ISW submersible developed. Based extended Korteweg–de Vries (eKdV) theory, generated two-layer fluid wave tank by solving Navier–Stokes (N–S) equation. By introducing hydrodynamic loadings provided environment into standard operation equation submersible, six degrees-of-freedom motions can be obtained. The dynamic overset mesh technology adopted to simulate field. present validated comparing with experiment submerged cylinder environment. Using model, we compare effects fixed, suspended, discuss influences propulsive forces ISW–structure effects. results show that movements change remarkably surge, heave, pitch direction. Especially, high pierce surface reach large angle amplitude 36°, further 35% motion speed decrease initial propulsion

Language: Английский

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Numerical investigation on motion response and load characteristics of interaction between internal solitary wave and multi-unmanned underwater vehicles

Ocean Engineering, Journal Year: 2025, Volume and Issue: 320, P. 120156 - 120156

Published: Jan. 11, 2025

Language: Английский

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Experimental investigation of propagation evolution characteristics of internal solitary waves passing through downslope topography

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(3)

Published: March 1, 2024

In contrast to the extensive research on propagation evolution of internal solitary waves (ISWs) over continental shelf topography, few investigations have been conducted ISWs downslope topography. this experiment, characteristics passing a topography were investigated in an immiscible two-layer fluid system clearly capture waveform information. The main objective study was analyze with different incident amplitudes through Using particle image velocimetry technique, evolutionary (such as waveform, wave height, energy budget, and flow field) are investigated. According field analysis results, phase velocity near changes ISWs. Moreover, gradient distribution progressively becomes perpendicular right surface Furthermore, counterclockwise vortex gradually forms at upper vertex is influenced by varying water depth front significantly flat, back steeper than original waveform. Around tail wave, upward convex packet generated. trends height losses broadly consistent. loss related 20% higher rate for large-amplitude small-amplitude inflection point

Language: Английский

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Experimental Investigation on the Vertical Structure Characteristics of Internal Solitary Waves

Journal of Marine Science and Engineering, Journal Year: 2022, Volume and Issue: 10(8), P. 1045 - 1045

Published: July 29, 2022

An experimental investigation of the vertical structure characteristics internal solitary waves (ISWs) was systematically carried out in a large gravitationally stratified fluid flume. Four different stratifications were established, and basic elements ISWs measured by conductivity probe array. The distributions amplitude, characteristic frequency waveform two types under obtained, results compared with theoretical model. study shows that most structures amplitude agree those model, while there are some deviations for amplitudes. Neither two-layer model nor continuously can effectively describe variation at depths amplitude. For single small-amplitude ISW, first increases then decreases increasing depth. is largest depth maximum buoyancy frequency. an ISW relatively likely to be local minimum near where lies. In stratifications, sech2 function KdV theory waveforms well.

Language: Английский

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Analysis of the Differences in Internal Solitary Wave Characteristics Retrieved from Synthetic Aperture Radar Images under Different Background Environments in the Northern South China Sea

Remote Sensing, Journal Year: 2023, Volume and Issue: 15(14), P. 3624 - 3624

Published: July 20, 2023

Two internal solitary waves (ISWs) with very long fronts observed by synthetic aperture radar (SAR) images in the northern South China Sea (NSCS) are comparatively analyzed based on oceanic reanalysis data and Korteweg–de Vries (KdV) theory. The differences environmental parameters, wave half-width, amplitude of two ISW distinct environments studied. In presence a weak westward surface current approximately 0.05 m/s, values linear speed increase up to 0.056 retrieved amplitudes decrease 14 m. On contrary, for another background environment considering relatively strong eastward 0.2 there decreases 0.17 m/s increases 32 m amplitudes. However, results from both SAR observations commonly show that along reach their maximums at roughly 21°N toward southern sides, spite environments.

Language: Английский

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Impact of seepage flow on sediment resuspension by internal solitary waves: parameterization and mechanism

Journal of Oceanology and Limnology, Journal Year: 2022, Volume and Issue: 41(2), P. 444 - 457

Published: May 3, 2022

Language: Английский

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Strongly non-linear Boussinesq-type model of the dynamics of internal solitary waves propagating in a multilayer stratified fluid

Physics of Fluids, Journal Year: 2023, Volume and Issue: 35(7)

Published: July 1, 2023

We propose a system of first-order balance laws that describe the propagation internal solitary waves in multilayer stratified shallow water with non-hydrostatic pressure upper and lower layers. The construction this model is based on use additional variables, which make it possible to approximate Green–Naghdi-type dispersive equations by system. In Boussinesq approximation, governing allow one simulate non-linear waves, taking into account fine density stratification, weak velocity shear layers, uneven topography. obtain smooth steady-state soliton-like solutions proposed form symmetric non-symmetric mode-2 adjoining given constant flow. Numerical calculations generation large-amplitude are carried out using both equations. It established these models practically coincide. advantage simplicity numerical implementation significant reduction calculation time. show results simulation good agreement experimental data evolution tanks variable height.

Language: Английский

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Numerical study on the forces and moments on a bottom-mounted cylinder by internal solitary wave

Journal of Fluids and Structures, Journal Year: 2023, Volume and Issue: 121, P. 103952 - 103952

Published: July 19, 2023

Language: Английский

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Laboratory Studies of Internal Solitary Waves Propagating and Breaking over Submarine Canyons

Journal of Marine Science and Engineering, Journal Year: 2023, Volume and Issue: 11(2), P. 355 - 355

Published: Feb. 5, 2023

This paper carried out laboratory experiments to study evolution of internal solitary waves (ISWs) over submarine canyons with a combination PIV (particle image velocimetry) and PLIF (planar laser-induced fluorescence) techniques. Taking canyon angle θ collapse height ∆H as variables, Froude number Fr, head position, energy loss, vorticity field turbulence intensity when ISWs propagate the were analyzed. According Fr values, cases can be divided into three types: > 1.7 means complete hydraulic jump (IHJ); 1 < denotes wavy IHJ represents no IHJ. The greater angle, depth amplitude incident wave more easily generate IHJs, which lead in area. Among all cases, case showing an obvious bimodal distribution are smaller than cases. For IHJ, dissipation is not obvious, average turbulent performs “sharp unimodal distribution”. Complete last for long time cause violent mixing, largest its presents “gentle single peak” pattern. 180° conditions (no cases), less delivered reflected dissipated near terrain, so loss comparison other conditions. These findings will deepen our understanding mechanisms propagating canyons.

Language: Английский

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