• Title/Summary/Keyword: nonlinear wave model

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Control of complex distillation configuration (복합 증류계의 제어)

  • 한명완;박선원
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.742-748
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    • 1993
  • The dynamics and control of two complex column configurations (sidestream column with stripper; prcfractionater/sidestream column configuration), which are multivariable interacting and nonlinear, have been studied. A new control scheme developed by Hanand Park(1993) to deal with the nonlinear and multivariable nature of distillation processes has been applied to these complex distillation configurations. The control scheme incorporates a nonlinear wave model into a generic model control framework. An observer based on the nonlinear wave model is used to determine the profile positions of distillation column sections. The control scheme enables tight control of the profile position of each column section that leads to fast stabilization of product compositions.

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Prediction of Wave-Induced Current Using Time-Dependent Wave Model (쌍곡선형 파랑모형을 이용한 해빈류 예측)

  • 김재중;이정만
    • Journal of Korean Port Research
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    • v.12 no.2
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    • pp.269-280
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    • 1998
  • A Wave-induced current model is developed in our study and this model is composed with wave transform model and current model. Two types of wave model are used in our study one is Copeland(1985) type which is applied in the offshore region and the other is Watanabe and Maruyama(1984) type which is applied in the surf zone. The depth-integrated and time-averaged governing equation of an unsteady nonlinear form is used in the wave induced current model. Lateral mixing radiation stresses surface and bottom stresses are considered in our current model. Copeland’s(1976) is used as a surface friction formula. Numerical solutions are obtained by Leendertse scheme and compared with Noda’s(1974) experimental results for the uniform slope coastal region test and Nishimura & Naruyama’s (1985) experimental results and numerical simulation results for the detached breakwater. The results from our wave model and wave model and wave-induced current model show good agreements with the others and also show nonlinear effects around the detached breakwater. The model in this study can be applied in the surf zone considering the friction stresses.

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Nonlinear Effects on a Ship Motion and Wave Load (비선형성(非線型性)을 고려(考慮)한 규칙파중(規則波中) 선체응답(船體應答)에 관(關)한 연구(硏究))

  • J.H.,Hwang;Y.J.,Kim;J.Y.,Kim;I.G.,Oh
    • Bulletin of the Society of Naval Architects of Korea
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    • v.22 no.3
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    • pp.1-8
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    • 1985
  • In this paper, the motion response and wave load of a container ship are treated by a nonlinear motion theory, which is similar to that used by Yamamoto et. al.[1]. This paper deals with the vertical motion response in oblique waves and the effect of the Smith correction in buoyancy force calculation. In the present computation, for S-175 container ship model our result also shows that the ratio of the motion peak to peak value to the wave height decreases as the wave height increases, which was obtained earlier by Yamamoto et.al.[3]. On the other hand the nondimensional midship bending moment increases as the wave height increases. These nonlinear effects are dominant near the resonance frequency, and depend on the hull form and forward speed. However, it is found that these nonlinear effects are significant for tanker model.

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Shoaling and Breaking Characteristics of Fully Nonlinear Boussinesq Model (완전비선형 Boussinesq 모형의 천수 및 쇄파 특성)

  • YOON JONG-TAE;PARK SEUNG-MIN
    • Journal of Ocean Engineering and Technology
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    • v.19 no.2 s.63
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    • pp.29-33
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    • 2005
  • The accuracy of predicting wave transformation in the nearshore is very important to wave hydrodynamics, sediment transport, and design of coastal structures. Numerical experiments are conducted to identify the shoaling and breaking characteristics of a fully nonlinear Boussinesq equation-based model. Simulated shoaling showed good agreement with the Shouto's formula, and the results of the breaking experiment agreed well with experimented data, over several beach profile.

Deep Water Wave Model for the East Sea (東海에서의 파랑추산을 위한 심해파랑모형에 대한 연구)

  • Yoon, Jong-Tae
    • Journal of Ocean Engineering and Technology
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    • v.13 no.2 s.32
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    • pp.116-128
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    • 1999
  • A deep water wave prediction model applicable to the East Sea is presnted. This model incorporates rediative transter of energy specrum, atmospheric input form the wind, nonlinear interaction, and energy dissipation by white capping. The propagation scheme by Gadd shows satisfactory results and the characteristics of the nonlinear interaction is simulated well by discrete interaction approximatiion. The application of the model to the sea around the Korean Peninsula shows reasonable agreement with the observation.

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DEVELOPMENT OF A NEW MODEL FOR NONLINEAR-DISPERSIVE WAVES OVER ARBITRARY DEPTHS

  • Nadaoka, Kazuo
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1998.09a
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    • pp.5-11
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    • 1998
  • Wave nonlinearity and dispersivity have mutually counteracting effects on the wave evolution process; i.e., the former makes the wave profile steeper, while the latter milder. Therefore to describe evolution of nonlinear water waves under general condition such as nonlinear random waves over arbitrary depths, both the wave nonlinearity and dispersivity must be properly taken into account in the wave modeling. (omitted)

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Development of Multidirectional Nonlinear Numerical Wave Tank by Naoe-FOAM-SJTU Solver

  • Cao, Hong-Jian;Wan, De-Cheng
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.1
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    • pp.14-24
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    • 2015
  • A three-dimensional multidirectional nonlinear numerical wave tank (NWT) based on the Navier-Stokes equations and the Finite Volume Method (FVM) is developed by using the two-phase hydrodynamic flow solver naoe-FOAM-SJTU based on the open source toolbox OpenFOAM. The free surface is capturing with the Volume Of Fluids (VOF). The directional wave including Stokes wave, solitary wave and nonlinear wave are simulated and verified. The multi-directional waves are also simulated with particular wave spectral such as JONSWAP and wave directional spreading function. The obtained numerical results show the capability of the solver to generate different type of multidirectional nonlinear waves accurately. Meanwhile, it implies that the presented NWT can easily extend to model the wave-structures interactions, which will be great help to the offshore structures design.

Development of Multidirectional Nonlinear Numerical Wave Tank by Naoe-FOAM-SJTU Solver

  • Cao, Hong-Jian;Wan, De-Cheng
    • International Journal of Ocean System Engineering
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    • v.4 no.1
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    • pp.49-56
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    • 2014
  • A three-dimensional multidirectional nonlinear numerical wave tank (NWT) based on the Navier-Stokes equations and the Finite Volume Method (FVM) is developed by using the two-phase hydrodynamic flow solver naoe-FOAM-SJTU based on the open source toolbox OpenFOAM. The free surface is capturing with the Volume Of Fluids (VOF). The directional wave including Stokes wave, solitary wave and nonlinear wave are simulated and verified. The multi-directional waves are also simulated with particular wave spectral such as JONSWAP and wave directional spreading function. The obtained numerical results show the capability of the solver to generate different type of multidirectional nonlinear waves accurately. Meanwhile, it implies that the presented NWT can easily extend to model the wave-structures interactions, which will be great help to the offshore structures design.

On Long Wave Induced by a Sub-sea Landslide Using a 2D Numerical Wave Tank

  • Koo, Weon-Cheol;Kim, Moo-Hyun
    • Journal of Ocean Engineering and Technology
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    • v.21 no.5
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    • pp.1-8
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    • 2007
  • A long wave induced by a Gaussian-shape submarine landslide is simulated by a 2D fully nonlinear numerical wave tank (NWT). The NWT is based on the boundary element method and the mixed Eulerian/Lagrangian approach. Using the NWT, physical characteristics of land-slide tsunami, including wave generation, propagation, particle kinematics, hydrodynamic pressure, run-up and depression, are simulated for the early stage of long wave generation and propagation. Various sliding mass heights are applied to the developed model for a systematic sensitivity analysis. In particular, the fully nonlinear NWT results are compared with linear results (exact body-boundary conditions with linear free-surface conditions) to identify the nonlinear effects in the respective cases.