scholarly journals Numerical Study on the Temporal Discretization Schemes in Two-Phase Wave Simulation

2019 ◽  
Author(s):  
Young Jun Kim ◽  
Benjamin Bouscasse ◽  
Sopheak Seng ◽  
David Le Touze
Keyword(s):  
Viscous Flow ◽  
Numerical Study ◽  
Second Order ◽  
Linear Wave ◽  
Two Dimensional ◽  
Discretization Scheme ◽  
Two Phase ◽  
Flow Solver ◽  
Temporal Discretization ◽  
Discretization Schemes

Abstract The generation and propagation of waves in a viscous flow solver are indispensable part of naval computational fluid dynamic (CFD) applications. This paper presents numerical simulations of two-dimensional wave propagation in the framework of two-phase finite volume method (FVM) with different temporal discretization schemes. Implicit Euler, Crank-Nicolson (CN) and second-order backward temporal discretization schemes are compared by using viscous flow solver based on the open source library OpenFOAM. The combinations of each temporal discretization scheme and explicit limiter are used for the formulation of the Volume Of Fluid (VOF) field convection equation. A new formulation using the second-order backward temporal discretization scheme with explicit limiter are investigated. Two-dimensional periodic domains are considered to compare different time-stepping methods. Also, five different refinement levels of meshes are used to study the convergence properties of each method. The non-linear wave is generated with stream function wave theory using ‘foamStar’, which is a specialized OpenFOAM library package developed by Bureau Veritas in collaboration with École Centrale de Nantes.

Numerical study of air-water two-phase flow in a two-dimensional vertical helical channel

2019 ◽  
Vol 52 (1) ◽  
pp. 015501
Author(s):  
Shirin Najafizadeh ◽  
Afshin Ahmadi Nadooshan ◽  
Morteza Bayareh
Keyword(s):  
Two Phase Flow ◽  
Numerical Study ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Helical Channel

A NUMERICAL STUDY OF TWO-PHASE FLOW USING A TWO-DIMENSIONAL TWO-FLUID MODEL

2004 ◽  
Vol 45 (10) ◽  
pp. 1049-1066 ◽  
Author(s):  
Moon-Sun Chung ◽  
Seung-Kyung Pak ◽  
Keun-Shik Chang
Keyword(s):  
Two Phase Flow ◽  
Numerical Study ◽  
Fluid Model ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Two Fluid Model ◽  
Two Fluid

Numerical study of two-dimensional viscous flow over dams

2003 ◽  
Vol 7 (3) ◽  
pp. 234-240
Author(s):  
Li-Bing Wang ◽  
Yu-Lu Liu ◽  
Min-Jie Tu
Keyword(s):  
Viscous Flow ◽  
Numerical Study ◽  
Two Dimensional

Propeller Effect on 3D Flow at the Stern Hull of a LNG Carrier Using Finite Volume Method

2014 ◽  
Vol 554 ◽  
pp. 566-570
Author(s):  
Mehdi Nakisa ◽  
Adi Maimun Abdul Malik ◽  
Yasser M. Ahmed ◽  
Sverre Steen ◽  
Fatemeh Behrouzi ◽  
...  
Keyword(s):  
Viscous Flow ◽  
Finite Volume ◽  
Cfd Simulation ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Computational Domain ◽  
Two Phase ◽  
Sst Turbulence Model

Numerical study and RANS simulations have been applied to investigate the incompressible free surface flow around the stern hull of Liquefied Natural Gas (LNG) ship affected by working propeller behind of her. Experimental works are carried out using LNG ship model in Marine Teknologi Center (MTC) of Univrsiti Teknologi Malaysia (UTM) to verify the computational fluid dynamic (CFD) results. Ansys-CFX 14.0 based on viscous flow finite volume code using the two-phase Eulerian–Eulerian fluid approach and shear stress transport (SST) turbulence model have been used in this study. A tetrahedral unstructured combined with prism grid were used with the viscous flow code for meshing the computational domain of water surface around it. CFD simulation has been verified using available experimental results. Finally, the flow structure, streamlines, velocity and pressure distribution around stern hull and propeller zone are discussed and analysed.

A Numerical Study of Unsteady Natural Convection in a Rectangular Enclosure: Transition From Laminar to Turbulent Flow

2010 ◽  
Author(s):  
K. M. Akyuzlu ◽  
M. Chidurala
Keyword(s):  
Mathematical Model ◽  
Finite Difference ◽  
Turbulent Flow ◽  
Numerical Study ◽  
Second Order ◽  
Working Fluid ◽  
Two Dimensional ◽  
Rectangular Enclosure ◽  
Circulation Patterns ◽  
Vertical Walls

A two-dimensional, mathematical model is adopted to investigate the development of buoyancy driven circulation patterns and temperature stratification inside a rectangular enclosure. One of the vertical walls of the enclosure is kept at a higher temperature then the opposing vertical wall. The top and the bottom of the enclosure are assumed insulated. The physics based mathematical model for this problem consists of conservation of mass, momentum (two-dimensional, unsteady Navier-Stokes equations for turbulent compressible flows), and energy equations for the enclosed fluid subjected to appropriate boundary conditions. A standard two equation turbulence model is used to model the turbulent flow in the enclosure. The compressibility of the working fluid is represented by an ideal gas relation. The conservation equations are discretized using an implicit finite difference technique which employs second order accurate central differencing for spatial derivatives and second order (based on Taylor expansion) finite differencing for time derivatives. The linearized finite difference equations are solved using a Coupled Modified Strongly Implicit Procedure (CMSIP) for the unknowns of the problem. Numerical experiments were then carried out to simulate the development of the buoyancy driven circulation patterns inside rectangular enclosures (with aspects ratios 0.5, 1 and 1.5) filled with a compressible fluid (Pr = 0.72). Experiments were repeated for various wall temperature differences which corresponded to Rayleigh numbers between 104 and 106. Changes in unsteady circulation patterns, temperature contours, and vertical and horizontal velocity profiles were predicted while the flow inside the enclosure transferred from laminar to turbulent flow due to the sudden temperature change imposed on the vertical walls of the enclosure. Only the results of the enclosure with aspect ratio one is presented in this paper. These results indicate that this transition is characterized by unicellular circulation patterns breaking up in to multicellular formations and increase in the values of the predicted wall heat fluxes and Nusselt number as flow becomes turbulent.

Numerical Calculation of the Viscous Hydrodynamic Forces on a KVLCC Hull Sailing Along Channel Bank

2012 ◽  
Author(s):  
Peng-yu Lou ◽  
Zao-Jian Zou
Keyword(s):  
Viscous Flow ◽  
Numerical Study ◽  
Lateral Force ◽  
Hydrodynamic Forces ◽  
Practical Significance ◽  
Flow Solver ◽  
Viscous Hydrodynamic ◽  
Unsteady Rans ◽  
And Control ◽  
Yaw Moment

In restricted waters, ships often need to navigate along banks of the waterways. In such case, the hydrodynamic lateral force and yaw moment acting on the ships will be induced due to the asymmetric flow about the ship hull. Accurately predicting these force and moment is of practical significance to ensure a safe navigation and can provide some guidance on correct manoeuvring and control of ships in restricted waters. In the present paper, to study the bank effects on the hydrodynamic forces acting on a ship manoeuvring in restricted waters, the viscous flow around an unappended ship sailing in a straight course along the channel bank and simultaneously undergoing sway motion is numerically simulated by using a CFD-based viscous flow solver. The steady and unsteady RANS equations in conjunction with a RNG k-ε turbulence model are solved by using the dynamic mesh technique and UDF (User-Defined Function). Numerical study is conducted for a KVLCC model. The hydrodynamic lateral force and yaw moment acting on the hull are calculated at different ship-to-bank distance and different water depth. By comparing the numerical results, the effects of ship-to-bank distance on the hydrodynamic forces are analyzed.

scholarly journals Numerical Modeling of Transcritical and Supercritical Fuel Injections Using a Multi-Component Two-Phase Flow Model

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5676
Author(s):  
Bittagowdanahalli Manjegowda Ningegowda ◽  
Faniry Nadia Zazaravaka Rahantamialisoa ◽  
Adrian Pandal ◽  
Hrvoje Jasak ◽  
Hong Geun Im ◽  
...  
Keyword(s):  
Transport Model ◽  
Numerical Study ◽  
Chamber Pressure ◽  
Reacting Flow ◽  
Mixing Processes ◽  
Two Phase ◽  
Flow Solver ◽  
Cubic Equation ◽  
Real Fluid ◽  
Quantitative Analyses

In the present numerical study, implicit large eddy simulations (LES) of non-reacting multi-components mixing processes of cryogenic nitrogen and n-dodecane fuel injections under transcritical and supercritical conditions are carried out, using a modified reacting flow solver, originally available in the open source software OpenFOAM®. To this end, the Peng-Robinson (PR) cubic equation of state (EOS) is considered and the solver is modified to account for the real-fluid thermodynamics. At high pressure conditions, the variable transport properties such as dynamic viscosity and thermal conductivity are accurately computed using the Chung transport model. To deal with the multicomponent species mixing, molar averaged homogeneous classical mixing rules are used. For the velocity-pressure coupling, a PIMPLE based compressible algorithm is employed. For both cryogenic and non-cryogenic fuel injections, qualitative and quantitative analyses are performed, and the results show significant effects of the chamber pressure on the mixing processes and entrainment rates. The capability of the proposed numerical model to handle multicomponent species mixing with real-fluid thermophysical properties is demonstrated, in both supercritical and transcritical regimes.

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