A numerical study of the generation and propagation of internal solitary waves in the Luzon Strait

Oceanic observations from western Europe and the south-western Indian ocean have provided evidence of the generation of internal solitary waves due to an internal tidal beam impinging on the pycnocline from below – a process referred to as ‘local generation’ (as opposed to the more direct generation over topography). Here we present the first direct numerical simulations of such a generation process with a fully nonlinear non-hydrostatic model for an idealised configuration. We show that, depending on the parameters, different modes can be excited and we provide examples of internal solitary waves as first, second and third modes, trapped in the pycnocline. A criterion for the selection of a particular mode is put forward, in terms of phase speeds. In addition, another simpler geometrical criterion is presented to explain the selection of modes in a more intuitive way. Finally, results are discussed and compared with the configuration of the Bay of Biscay.

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Mooring observations of internal solitary waves in the deep basin west of Luzon Strait

Acta Oceanologica Sinica ◽

10.1007/s13131-014-0416-7 ◽

2014 ◽

Vol 33 (3) ◽

pp. 82-89 ◽

Cited By ~ 15

Author(s):

Xiaodong Huang ◽

Wei Zhao ◽

Jiwei Tian ◽

Qingxuan Yang

Keyword(s):

Solitary Waves ◽

Luzon Strait ◽

Internal Solitary Waves ◽

Deep Basin

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NONLINEAR OBLIQUE INTERACTION OF LARGE AMPLITUDE INTERNAL SOLITARY WAVES

Coastal Engineering Proceedings ◽

10.9753/icce.v33.waves.19 ◽

2012 ◽

Vol 1 (33) ◽

pp. 19

Author(s):

Keisuke Nakayama ◽

Taro Kakinuma ◽

Hidekazu Tsuji ◽

Masayuki Oikawa

Keyword(s):

Solitary Waves ◽

Water Waves ◽

Large Amplitude ◽

Numerical Study ◽

Incident Angle ◽

Resonant Interaction ◽

Internal Solitary Waves ◽

Weakly Nonlinear ◽

Wave Angle ◽

The One

Solitary waves are typical nonlinear long waves in the ocean. The two-dimensional interaction of solitary waves has been shown to be essentially different from the one-dimensional case and can be related to generation of large amplitude waves (including ‘freak waves’). Concerning surface-water waves, Miles (1977) theoretically analyzed interaction of three solitary waves, which is called “resonant interaction” because of the relation among parameters of each wave. Weakly-nonlinear numerical study (Funakoshi, 1980) and fully-nonlinear one (Tanaka, 1993) both clarified the formation of large amplitude wave due to the interaction (“stem” wave) at the wall and its dependency of incident angle. For the case of internal waves, analyses using weakly nonlinear model equation (ex. Tsuji and Oikawa, 2006) suggest also qualitatively similar result. Therefore, the aim of this study is to investigate the strongly nonlinear interaction of internal solitary waves; especially whether the resonant behavior is found or not. As a result, it is found that the amplified internal wave amplitude becomes about three times as much as the original amplitude. In contrast, a "stem" was not found to occur when the incident wave angle was more than the critical angle, which has been demonstrated in the previous studies.

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An Iterative Updating Method for Dynamic Responses of a Floating Platform Under Action of Internal Solitary Waves

Volume 1: Offshore Technology; Offshore Geotechnics ◽

10.1115/omae2019-96553 ◽

2019 ◽

Author(s):

Wang Junrong ◽

Du Junfeng ◽

Zhang Min ◽

Chang Anteng

Keyword(s):

South China Sea ◽

Solitary Waves ◽

South China ◽

Numerical Study ◽

Ocean Current ◽

Internal Solitary Waves ◽

Floating Structures ◽

Oil Companies ◽

China Sea ◽

Fluid Body

Abstract The internal solitary waves, have properties of two-way shear profile, significant velocity and acceleration, etc., which threaten the safety of deepwater floating systems in South China Sea (SCS), for the frequent occurrence and the high intensity of internal solitary waves in SCS. In recent years, offshore oil companies of China encountered many strong internal waves during its deepwater oil and gas exploration and development activities in South China Sea. However, the action mechanism of ISWs to floating structures is not understood clearly, and the internal solitary waves are classified as ocean current in API RP 2SK (3rd edition), therefore engineers ignore the velocity variance and long period “wave” characteristics in the design of floating structures. Furthermore, the offshore floating structures is oscillating under the action of environmental forces, due to the horizontal velocity of the platform is comparative to that of ISWs, thus fluid-body coupling is significant that one cannot analyse it by simply adding a specified ISW force time history to the floater. This paper proposes a new iterative updating method for ISW loading calculation considering the fluid-body coupling, and applied this method to a semi MODU, numerical study shows the iteration is efficient and the result is more reasonable compared to conventional method, and it is found that the maximal offset decreases significantly.

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