Validation and Verification of CE/SE Method Based Courant Number Insensitive Transient Viscous Flow Solver

This paper compares numerical and experimental results in the study of the resonance phenomenon which appears between two side-by-side fixed barges for different sea-states. Simulations were performed using SWENSE (Spectral Wave Explicit Navier-Stokes Equations) approach and results are compared with experimental data on two fixed barges with different headings and bilges. Numerical results, obtained using the SWENSE approach, are able to predict both the frequency and the magnitude of the RAO functions.

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A Hybrid Viscous/Potential Flow Method for the Prediction of the Performance of Podded and Ducted Propellers

10.5957/pss-2009-01 ◽

2009 ◽

Author(s):

Spyros A. Kinnas ◽

Shu-Hao Chang ◽

Yi-Hsiang Yu ◽

Lei He

Keyword(s):

Viscous Flow ◽

Lattice Method ◽

Viscous Potential Flow ◽

Flow Solver ◽

Vortex Lattice Method ◽

Ducted Propeller ◽

Hybrid Numerical Method ◽

Convergence Study ◽

Effective Wake ◽

Ducted Propellers

This paper presents the analysis of the performance for podded and ducted propellers using a hybrid numerical method, which couples a vortex lattice method (MPUF-3A) for the unsteady analysis of propellers and a viscous flow solver (NS-3X or FLUENT) for the prediction of the viscous flow around propulsors and the drag force on the pod and duct surfaces. The time averaged propeller force distributions are considered as source terms (body force) in the momentum equations of NS-3X and FLUENT. The effects of viscosity on the effective wake and on the performance of the propeller blade, as well as on the predicted pod and duct forces, are assessed. The convergence study of circulation distributions with number of lattices is reported in the ducted propeller case. Finally, the prediction of the performance for podded propellers (both single pull-type and twin-type) and ducted propellers from the present method is validated against existing experimental data.

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Generation of Regular and Irregular Waves in Navier-Stokes CFD Solvers by Matching With the Nonlinear Potential Wave Solution at the Boundaries

Volume 2: CFD and FSI ◽

10.1115/omae2018-78077 ◽

2018 ◽

Author(s):

Youngmyung Choi ◽

Benjamin Bouscasse ◽

Sopheak Seng ◽

Guillaume Ducrozet ◽

Lionel Gentaz ◽

...

Keyword(s):

Viscous Flow ◽

Open Source ◽

Cfd Simulation ◽

Irregular Waves ◽

Navier Stokes ◽

Wave Fields ◽

Flow Solver ◽

Nonlinear Potential ◽

Simulation Parameters ◽

2D And 3D

The capability of wave generation and absorption in a viscous flow solver becomes important for achieving realistic simulations in naval and offshore fields. This study presents an efficient generation of nonlinear wave fields in the viscous flow solver by using a nonlinear potential solver called higher-order spectral method (HOS). The advantages of using a fully nonlinear potential solver for the generation of irregular waves are discussed. In particular, it is shown that the proposed method allows the CFD simulation to start at the time and over the space of interest, retrieved from the potential flow solution. The viscous flow solver is based on the open source library OpenFOAM. The potential solvers used to generate waves are the open source solvers HOS-Ocean and HOS-NWT (Numerical Wave Tank). Several simulation parameters in the CFD solver are investigated in the present study. A HOS wrapper program is newly developed to regenerate wave fields in the viscous flow solver. The wrapper program is validated with OpenFOAM for 2D and 3D regular and irregular waves using relaxation zones. Finally, the extreme waves corresponding to the 1000 year return period condition in the Gulf of Mexico are simulated with the viscous flow solver and the wave elevation is compared with the experiments.

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