Numerical and Experimental Study of the Flow Around Two Ship Sections Side-by-Side

This paper reports calculations of three dimensional (3D) unsteady cross flow over two ship sections in close proximity and compares the results with measurements. The ship sections have different breadth and draft, and represent typical situations in a ship-to-ship marine operation in a cross current. The behavior of the vortex-shedding around the two different ship hull sections is investigated numerically by CFD methods and experiments. For the two sections, simulations are done for several Reynolds numbers by using the dynamic Smagorinsky Large Eddy Simulation (LES) turbulence model. Finally the cross flow past the ship sections in side-by-side position is simulated and vortex interaction between the sections is found by using the software (Ansys) FLUENT. The numerical predictions are compared with PIV results taken in a circulating water tunnel.

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Investigation of the Flow Around Two Interacting Ship-Like Sections

Journal of Fluids Engineering ◽

10.1115/1.4028876 ◽

2015 ◽

Vol 137 (4) ◽

Cited By ~ 2

Author(s):

Tufan Arslan ◽

Bjørnar Pettersen ◽

Helge I. Andersson

Keyword(s):

Vortex Shedding ◽

Particle Image ◽

Three Dimensional ◽

Cross Flow ◽

Eddy Simulation ◽

Image Velocimetry ◽

Large Eddy ◽

Close Proximity ◽

Computational Fluid Dynamics Cfd ◽

Cross Current

This paper reports calculations of three-dimensional (3D) unsteady cross flow over two ship sections in close proximity and compares the results with measurements. The ship sections have different breadth and draft conditions which represent typical situations in a ship-to-ship marine operation in a cross current. The behavior of the vortex-shedding around the two different ship hull sections is investigated numerically by computational fluid dynamics (CFD) methods. For the two sections, simulations are done for Reynolds number Re = 68,000, Froude number Fr = 0.25, and Re = 6800, Fr = 0.025 by using the dynamic Smagorinsky large eddy simulation (LES) turbulence model. The simulations are performed by using the software ansysfluent and the numerical results are compared with particle image velocimetry (PIV) results taken from the literature. The hydrodynamic forces acting on the two ship sections are predicted by numerical simulations and interaction effects between the two ships are evaluated.

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Large Eddy Simulation of Cross Flow in Pipe Junction

Volume 2: CFD and FSI ◽

10.1115/omae2018-77751 ◽

2018 ◽

Author(s):

Jiajun Chen ◽

Yue Sun ◽

Hang Zhang ◽

Dakui Feng ◽

Zhiguo Zhang

Keyword(s):

Large Eddy Simulation ◽

Stokes Equations ◽

Numerical Study ◽

Three Dimensional ◽

Cross Flow ◽

Exciting Force ◽

Navier Stokes ◽

Pipe Network ◽

Eddy Simulation ◽

Large Eddy

Mixing in pipe junctions can play an important role in exciting force and distribution of flow in pipe network. This paper investigated the cross pipe junction and proposed an improved plan, Y-shaped pipe junction. The numerical study of a three-dimensional pipe junction was performed for calculation and improved understanding of flow feature in pipe. The filtered Navier–Stokes equations were used to perform the large-eddy simulation of the unsteady incompressible flow in pipe. From the analysis of these results, it clearly appears that the vortex strength and velocity non-uniformity of centerline, can be reduced by Y-shaped junction. The Y-shaped junction not only has better flow characteristic, but also reduces head loss and exciting force. The results of the three-dimensional improvement analysis of junction can be used in the design of pipe network for industry.

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Three-dimensional study of separated flow over a square cylinder by large eddy simulation

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1243/095441005x30207 ◽

2005 ◽

Vol 219 (3) ◽

pp. 225-234 ◽

Cited By ~ 6

Author(s):

M Farhadi ◽

M Rahnama

Keyword(s):

Large Eddy Simulation ◽

Three Dimensional ◽

Separated Flow ◽

Reynolds Numbers ◽

Square Cylinder ◽

Mean Flow ◽

Central Difference ◽

Eddy Simulation ◽

Flow Parameters ◽

Large Eddy

Large eddy simulation of flow over a square cylinder in a channel is performed at Reynolds numbers of 22 000 and 21 400. The selective structure function (SSF) modelling of the subgrid-scale stress terms is used and the convective terms are discretized using quadratic upstream interpolation for convective kinematics (QUICK) and central difference (CD) schemes. A series of time-averaged velocities, turbulent stresses, and some global flow parameters such as lift and drag coefficients and their fluctuations are computed and compared with experimental data. The suitability of SSF model has been shown by comparing the computed mean flow velocities and turbulent quantities with experiments. Results show negligible variation in the flow parameters for the two Reynolds numbers used in the present computations. It was observed that both QUICK and CD schemes are capable of obtaining results close to those of the experiments with some minor differences.

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3-D Numerical Simulation of Flow Around a Rectangular Cylinder

Volume 2: Symposia, Parts A, B, and C ◽

10.1115/fedsm2003-45624 ◽

2003 ◽

Author(s):

Akira Rokugou ◽

Atsushi Okajima ◽

Takanori Isogawa

Keyword(s):

Three Dimensional ◽

Time History ◽

Reynolds Numbers ◽

Eddy Simulation ◽

Eddy Viscosity Model ◽

Side Ratio ◽

Rectangular Cylinder ◽

Large Eddy ◽

History Of ◽

Rectangular Cylinders

Three-dimensional numerical simulations of the flow around rectangular cylinders with depth-to-height ratios (side ratio) of 3 and 6 at various Reynolds numbers were carried out using the Large eddy simulation (LES), which employs the Smagorinsky eddy-viscosity model, a type of subgrid scale (SGS) model. Computed results compared well with experimental ones. The irregular fluctuation of aerodynamic forces can be simulated. The time history of the lift force corresponded well to the variation of flow pattern.

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Application of Large Eddy Simulation to Flow Past a Circular Cylinder

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2829099 ◽

1997 ◽

Vol 119 (4) ◽

pp. 219-225 ◽

Cited By ~ 33

Author(s):

X. Lu ◽

C. Dalton ◽

J. Zhang

Keyword(s):

Circular Cylinder ◽

Large Eddy Simulation ◽

Stokes Equations ◽

Three Dimensional ◽

Reynolds Numbers ◽

Scale Model ◽

Step Method ◽

Fractional Step Method ◽

Eddy Simulation ◽

Large Eddy

A steady approach flow around a circular cylinder is investigated by using a large eddy simulation (LES) with the Smagorinsky subgrid-scale model. A second-order accurate in time fractional-step method and a combined finite-difference/spectral approximation are employed to solve the filtered three-dimensional incompressible Navier-Stokes equations. To demonstrate the viability and accuracy of the method, we present results at Reynolds numbers of 100, 3 × 103, 2 × 104, and 4.42 × 104. At Re = 100, the physical flow is two-dimensional and the calculation is done without use of the LES method. For the higher values of Re, the flow in the wake is three-dimensional and turbulent and the LES method is necessary to describe the flow accurately. Calculated values of lift and drag coefficients and Strouhal number are in good agreement with the experimentally determined values at all of the Reynolds numbers for which calculation was done.

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