Interaction of Fixed Cylinder With Waves Through Weakly Coupled FNPT and Lagrangian Navier-Stokes

2019 ◽  
Author(s):  
Shagun Agarwal ◽  
Venkatachalam Sriram ◽  
K. Murali
Keyword(s):  
Hybrid Approach ◽  
Wave Structure ◽  
Breaking Waves ◽  
Theory Model ◽  
Navier Stokes ◽  
Rankine Source ◽  
Weakly Coupled ◽  
Mesh Less ◽  
Wave Structure Interaction ◽  
Fixed Cylinder

Abstract This paper presents a 2D/3D hybrid numerical model for studying the interaction of non-breaking waves with cylindrical structure. The work combines the strengths of mesh-based and particle-based methods, where the wave propagation is solved using 2D mesh-based potential theory model and the interaction with the structure is solved using 3D particle-based Navier-Stokes model. The paper presents the formulation of the two models and the weak-coupling methodology, along with recent improvements in the 3D MLPG_R (Mesh-less Petrov-Galerkin based on Rankine source solution) particle based method. The numerical results from interaction of fixed cylinder with solitary and focussed waves are compared with experimental data. The work demonstrates a significant reduction in simulation time for wave-structure interaction problems achieved using this hybrid approach without compromising on accuracy.

Computational and Experimental Simulation of Nonbreaking and Breaking Waves for the Investigation of Structural Loads and Motions

2006 ◽  
Author(s):  
Gu¨nther F. Clauss ◽  
Robert Stu¨ck ◽  
Florian Stempinski ◽  
Christian E. Schmittner
Keyword(s):  
Data Transfer ◽  
Stokes Equations ◽  
Wave Structure ◽  
Breaking Waves ◽  
Experimental Simulation ◽  
Navier Stokes ◽  
Wave Crest ◽  
Breaking Wave ◽  
Simulation Code ◽  
Wave Trains

For the analysis of loads and motions of marine structures in harsh seaways precise information about the hydrodynamics of waves is required. While the surface motion of waves can easily be measured in physical wave tanks other critical characteristics such as the instantaneous particle velocity and acceleration as well as the pressure field, especially under the wave crest are difficult and time-consuming to obtain. Therefore a new method is presented to approximate the wave potential of a given instantaneous wave contour. Numerical methods — so called numerical wave tanks (NWTs) — are developed to provide the desired insight into wave hydrodynamics. A potential theory method based on the Finite Element method (Pot/FE), a RANSE (Reynolds-Averaged Navier-Stokes Equations) method applying VOF (Volume of Fluid) and a combination of both is utilized for the simulation of different model wave trains. The coupling of both CFD (computational fluid dynamics) solvers is a useful approach to benefit from the advantages of the two different methods: The Pot/FE solver WAVETUB (wave simulation code developed at Technical University Berlin) allows a very fast and accurate simulation of the propagation of nonbreaking waves while the RANSE/VOF solver has the capability of simulating breaking waves. Two different breaking criteria for the detection of wave breaking are implemented in WAVETUB for triggering the automated coupling process by data transfer at the interface. It is shown that an efficient method for the simulation of breaking wave trains including wave-structure interaction in 2D and 3D is established by the coupling of both CFD codes. All results are discussed in detail.

Scaled Boundary FEM Solution of 2D Steady Incompressible Viscous Flows

2008 ◽  
Author(s):  
Longbin Tao ◽  
Hao Song
Keyword(s):  
Viscous Flow ◽  
Wave Structure ◽  
Viscous Flows ◽  
Navier Stokes ◽  
Fluid Structure Interactions ◽  
Structure Interaction ◽  
Constant Vorticity ◽  
Incompressible Viscous Flows ◽  
Engineering Problems ◽  
Wave Structure Interaction

In this paper, the scaled boundary finite-element method (SBFEM) proposed for wave-structure interaction [Tao et al, 2007] is extended to solve two-dimensional (2D) steady incompressible viscous flows governed by the Navier-Stokes (N-S) equations. The present SBFEM scheme is validated against existing analytical solutions of the 2D viscous flow with a constant vorticity. Comparisons clearly demonstrate the excellent accuracy and computational efficiency associated with the present SBFEM. Such superiority in significantly outperforming its counterparts in currently available CFD software ensures a great potential of direct application of the present method to many engineering problems. As a crucial step in expanding the application of the SBFEM, further extension of the SBFEM to to solve viscous flow of variable vorticity or even more complex viscous fluid-structure interactions will be a welcome development.

scholarly journals Numerical investigation of the three-dimensional velocity fields induced by wave-structure interaction

2019 ◽  
Vol 24 ◽  
pp. 02011
Author(s):  
Giovanni Cannata ◽  
Francesco Gallerano ◽  
Federica Palleschi ◽  
Chiara Petrelli ◽  
Luca Barsi
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Wave Structure ◽  
Integral Form ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Structure Interaction ◽  
Wave Trains ◽  
Hydrodynamic Effects ◽  
Wave Structure Interaction

Submerged shore-parallel breakwaters for coastal defence are a good compromise between the need to mitigate the effects of waves on the coast and the ambition to ensure the preservation of the landscape and water quality. In this work we simulate, in a fully three-dimensional form, the hydrodynamic effects induced by submerged breakwaters on incident wave trains with different wave height. The proposed three-dimensional non-hydrostatic finite-volume model is based on an integral form of the Navier-Stokes equations in σ-coordinates and is able to simulate the shocks in the numerical solution related to the wave breaking. The obtained numerical results show that the hydrodynamic phenomena produced by wave-structure interaction have features of three-dimensionality (undertow), that are locally important, and emphasize the need to use a non-hydrostatic fully-three-dimensional approach.

SPH Method Applications for Coastal Wave Breaking and Wave-Structure Interaction

2012 ◽  
Vol 256-259 ◽  
pp. 1990-1993
Author(s):  
Zhi Gang Bai ◽  
Jun Zhao
Keyword(s):  
Wave Breaking ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Wave Structure ◽  
Navier Stokes ◽  
Sph Method ◽  
Structure Interaction ◽  
Promising Tool ◽  
Sph Model ◽  
Wave Structure Interaction

The Smoothed Particle Hydrodynamics (SPH) method is a mesh-free Lagrangian approach which is capable of tracking the large deformations of the free surface with good accuracy. A three-dimensional SPH model was proposed to simulate the wave–structure interaction (WSI), in which a weakly compressible SPH model was introduced to investigate the wave breaking and coastal structure. To validate the SPH numerical model, three different types of wave breaking, namely, spilling, plunging and surging breaking were successfully simulated. The computations were compared with the experimental data and a good agreement was observed. The hydrodynamics model of interaction between wave and structure was established according to Navier-Stokes equations in SPH style. And the model was used in simulating the interaction between wave and a series of new type breakwaters. It is proven to be a promising tool and able to provide reliable prediction on the wave-structure interaction in coastal engineering.

scholarly journals Progress in Coupling Potential Wave Models and Two-Phase Solvers With the SWENSE Methodology

2018 ◽  
Author(s):  
Zhaobin Li ◽  
Benjamin Bouscasse ◽  
Lionel Gentaz ◽  
Guillaume Ducrozet ◽  
Pierre Ferrant
Keyword(s):  
Potential Theory ◽  
Stokes Equations ◽  
Wave Structure ◽  
Navier Stokes ◽  
Computational Domain ◽  
Two Phase ◽  
Structure Interaction ◽  
Wave Models ◽  
Coupling Potential ◽  
Wave Structure Interaction

This paper presents the recent developments of the Spectral Wave Explicit Navier-Stokes Equations (SWENSE) method to extend its range of application to two-phase VOF solvers. The SWENSE method solves the wave-structure interaction problem by coupling potential theory and the Navier-Stokes (NS) equations. It evaluates the incident wave solution by wave models based on potential theory in the entire computational domain, leaving only the perturbation caused by the structure and the influence of the viscosity to be solved with CFD. The method was proven in previous studies to be accurate and efficient for wave-structure interaction problems, but it was derived for single-phase NS solvers only. The present study extends the SWENSE method by proposing a novel formulation which is convenient to implement in two-phase NS solvers. A customized SWENSE solver is developed with the open source CFD package Open-FOAM. An improvement in accuracy and stability is observed in wave simulations compared with conventional two-phase VOF solvers. The horizontal force on a vertical cylinder in regular waves is also calculated. First results show a good agreement with the experiment on the first harmonic component.

scholarly journals Numerical Investigation on the Collision between a Solitary Wave and a Moving Cylinder

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2167
Author(s):  
Emir Taha Eren ◽  
Mahdi Tabatabaei Malazi ◽  
Galip Temir
Keyword(s):  
Solitary Wave ◽  
Numerical Simulations ◽  
Surface Displacement ◽  
Wave Structure ◽  
Hydrodynamic Forces ◽  
Numerical Results ◽  
Navier Stokes ◽  
Moving Cylinder ◽  
Mesh Method ◽  
Wave Structure Interaction

A 2-D numerical wave tank (NWT) was applied for solving the interaction between a solitary wave and a moving circular cylinder. The cylinder was placed at various positions from the tank bed floor. The cylinder can move at a constant horizontal velocity towards the solitary wave. The collision between a solitary wave and a moving cylinder is investigated at various conditions. A total of fifteen cases were studied. Ten different numerical simulations were used, including five submergence depths and two different moving velocities. The other five different numerical simulations were studied when the cylinder was unmoved in the NWT for comparing wave-structure interaction results between the moving and unmoved cylinders. The numerical results were obtained by calculating Reynolds-Averaged Navier-Stokes (RANS) equations and the volume of fluid (VOF) equations. Two different codes (User-Define-Function-UDF) were used for the generation of a solitary wave by moving a wave paddle and traveling cylinder in the NWT. The dynamic mesh method was applied for recreating mesh. First, the ability of CFD codes to generate a solitary wave by using wave paddle movement and the hydrodynamic forces of a moving cylinder were validated by numerical results. Further, the free-surface elevation and hydrodynamic forces were considered at various conditions. The numerical results show that moving cylinder velocity and the space between the cylinder and the tank bed floor have significant effects on surface displacement and hydrodynamic forces.

Wave-Structure Interaction of Focussed Waves With REEF3D

2016 ◽  
Author(s):  
Hans Bihs ◽  
Mayilvahanan Alagan Chella ◽  
Arun Kamath ◽  
Øivind A. Arnsten
Keyword(s):  
Free Surface ◽  
Level Set ◽  
Wave Structure ◽  
High Order ◽  
Navier Stokes ◽  
Numerical Wave Tank ◽  
Wave Tank ◽  
Structure Interaction ◽  
Numerical Wave ◽  
Wave Structure Interaction

For the stability of offshore structures, such as offshore wind foundations, extreme wave conditions need to be taken into account. Waves from extreme events can become critical from design perspective. In a numerical wave tank, extreme waves can be generated through focussed waves. Here, linear waves are generated from a wave spectrum. The wave crests of the generated waves coincide at a pre-selected location and time. In order to test the generated waves, the time series of the free surface elevation are compared with experimental benchmark cases. The numerically simulated free surface shows good agreement with the measurements from experiments. In further computations, the wave impact of the focussed waves on a vertical circular cylinder is investigated. The focussed wave generation is implemented in the numerical wave tank module of REEF3D, which has been extensively and successfully tested for various wave hydrodynamics and wave-structure interaction problems in particular and for free surface flows in general. The open-source CFD code REEF3D solves the three-dimensional Navier-Stokes equations on a staggered Cartesian grid. Solid boundaries are taken into account with the ghost cell immersed boundary method. For the discretization of the convection terms of the momentum equations, the conservative finite difference version of the fifth-order WENO (weighted essentially non-oscillatory) scheme is used. For temporal treatment, the third-order TVD (total variation diminishing) Runge-Kutta scheme is employed. For the pressure, the projection method is used. The free surface flow is solved as two-phase fluid system. For the interface capturing, the level set method is selected. The level set function can be discretized with high-order differencing schemes. This makes it the appropriate solution for wave propagation problems based on Navier-Stokes solvers, which requires high-order numerical methods to avoid artificial wave damping. The numerical model is fully parallelized based on the domain decomposition, using MPI (message passing interface) for internode communication.

Image-clustering analysis of the wave–structure interaction processes under breaking and non-breaking waves

2021 ◽  
Vol 33 (10) ◽  
pp. 105121
Author(s):  
Sara Mizar Formentin ◽  
Maria Gabriella Gaeta ◽  
Roberto De Vecchis ◽  
Massimo Guerrero ◽  
Barbara Zanuttigh
Keyword(s):  
Clustering Analysis ◽  
Wave Structure ◽  
Breaking Waves ◽  
Image Clustering ◽  
Structure Interaction ◽  
Interaction Processes ◽  
Wave Structure Interaction

scholarly journals Investigation of a Stochastic Inverse Method to Estimate an External Force: Applications to a Wave-Structure Interaction

2012 ◽  
Vol 2012 ◽  
pp. 1-25 ◽  
Author(s):  
S. L. Han ◽  
Takeshi Kinoshita
Keyword(s):  
External Force ◽  
Inverse Method ◽  
Inverse Function ◽  
Wave Structure ◽  
Dynamic Responses ◽  
Structure Interaction ◽  
External Forces ◽  
Interaction Problem ◽  
Wave Structure Interaction

The determination of an external force is a very important task for the purpose of control, monitoring, and analysis of damages on structural system. This paper studies a stochastic inverse method that can be used for determining external forces acting on a nonlinear vibrating system. For the purpose of estimation, a stochastic inverse function is formulated to link an unknown external force to an observable quantity. The external force is then estimated from measurements of dynamic responses through the formulated stochastic inverse model. The applicability of the proposed method was verified with numerical examples and laboratory tests concerning the wave-structure interaction problem. The results showed that the proposed method is reliable to estimate the external force acting on a nonlinear system.

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