China
Africa
Explore chapters and articles related to this topic
Validation study for a heaving sphere in waves
Published in C. Guedes Soares, Developments in Renewable Energies Offshore, 2020
The CFD solver used for the simulations, OpenFOAM, is an open source library that numerically solves a wide range of problems in fluid dynamics from laminar to turbulent flows, with single and multi-phases. The governing equation is based on continuity and Reynolds averaged Navier-Stokes equation. The Volume of Fluid (VOF) method is used to model fluid as one continuum of mixed properties. Finite Volume Method (FVM) is used to discretize the governing equations. Pressure-velocity coupling is obtained through the PIMPLE algorithm. Mesh morphing technique is used to accommodate the dynamic simulations. For modeling turbulence, the stable version of SST k-ω turbulence model is used. The stable version of the model is used to avoid turbulence related instability and subsequent wave dissipation. The waves are generated using flap type wave generator and Stokes second order wave formulation is used. Further detail regarding the solver can be found in the paper by Jasak (2009).
An investigation into the effect of the Hull Vane on the ship resistance in OpenFOAM
Published in Petar Georgiev, C. Guedes Soares, Sustainable Development and Innovations in Marine Technologies, 2019
C. Celik, D.B. Danisman, P. Kaklis, S. Khan
OpenFOAM is an open source library which is written in C ++ language. It has an extensive capacity to carry out different kind of fluid dynamics problems such as laminar, turbulent, multiphase flows. In this study, 3-D, incompressible, unsteady Navier-Stokes equations are solved by applying the finite volume method in order to calculate the resistance components of the ship model. The vector notation of the governing equations of the flow are given below; Newman (2018) () ∇V=0, () ∂V∂t+(V∇)V=−1ρ∇p+ν∇2V+1ρF,
CFD modelling of near-field dam break flow
Published in Jean-Pierre Tournier, Tony Bennett, Johanne Bibeau, Sustainable and Safe Dams Around the World, 2019
S. Esmaeeli Mohsenabadi, M. Mohammadian, I. Nistor, H. Kheirkhah Gildeh
Flood flows have been studied by using numerical models during the past years and CFD has become one of the most beneficial tools in water resources engineering in both academia and industry. To simulate dam break flows in this study, the OpenFOAM model was used. OpenFOAM (OPEN Field Operation And Manipulation) is an open-source computational fluid dynamics model written in C++ which has been used in hydraulic engineering problems more frequently in past years (Shaheed et al., 2018; Kheirkhah et al. a, 2015; Kheirkhah et al. b, 2014; Kheirkhah et al. c, 2014). OpenFOAM model has the feature of being open-source for changes and developments, and new ideas can be contributed by users to help in extending the software features. Simulation of flow fields using various numerical schemes and turbulence models are possible within the model. The model also has the capability of parallel processing. Two types of application are available with this model: solvers that designed to solve a specific fluid mechanics problem, and utilities which are used to perform data manipulation. OpenFOAM uses the FVM and includes various numerical schemes that are implemented for both time and space integrations. For further information about how to use and program OpenFOAM, see (OpenCFD, 2015). The solver used in this study is interFoam, which is mostly used for incompressible free surface turbulent flows.
Energy buffer mechanism for heat transfer enhancement in grooved channel cooling with flow intermittency
Published in Numerical Heat Transfer, Part A: Applications, 2023
Zhihan Zhang, Yujie Tang, Qiang Zhang, Zhaoguang Wang
The present work numerically investigates the thermal performance of laminar intermittent flow in a channel with triangular grooves at different close time ratios. The open source computational fluid dynamics (CFD) code OpenFOAM is employed. The numerical solver is validated against classic analytical solution and experimental data previously published. The enhancement in heat transfer at various close time ratios is reported for the same time-averaged Reynolds number (Rem = 100) and intermittency frequency (Strouhal number St = 0.2). The dynamic evolution of vortical flow structures is discussed in detail, and an energy buffer mechanism by cavity vortices during the flow intermittency is illustrated. The novelty of the present work is that the proposed energy buffer mechanism elucidates the necessity of incorporating surface structures in unsteady flow to achieve effective heat transfer enhancement and that the adopted flow intermittency exhibits more design flexibilities and potentials in the time domain for thermal performance improvement than regular pulsation patterns.
SIMPLE adjoint message passing
Published in Optimization Methods and Software, 2018
OpenFOAM is a complex C++ simulation code that extensively uses advanced features such as polymorphism, function macros, templates and operator overloading. This level of complexity makes the application of state-of-the-art source code transformation AD tools only feasible on very limited numerical kernels, but not on the whole package. A discrete adjoint version of OpenFOAM using operator overloading was developed by applying dco/c++. Prior work includes the introduction of checkpointing [29] and AMPI used without symbolically differentiated linear solvers [30]. In the following, we mainly focus on the solution of the incompressible Navier–Stokes equations in the context of topology optimization, but a wide variety of other solvers (e.g. compressible Navier–Stokes, Euler flow, optimization of unsteady flow [27]) and utilities (meshing, pre-processing, post-processing) exist and are also usable within the discrete adjoint OpenFOAM framework. Also shape optimization, i.e. displacement of the surface nodes of the geometry to optimize for a chosen objective, can be achieved using the same techniques. Second and higher derivatives can also be computed within the framework but are not covered in this paper.
A study of long wave run-ups on a bi-linear beach slope induced by solitary and transient-focused wave group
Published in Coastal Engineering Journal, 2019
Haeng Sik Ko, Patrick J. Lynett
The OpenFOAM is an open-source Computational Fluid Dynamics (CFD) software, and consists of C++ libraries and codes that is used for creating applications including solvers or utilities (Weller et al., 1998). Solvers are each designed to solve a specific problem in continuum mechanics, and utilities are designed to perform tasks that involve data manipulation. The package distribution enables us to use numerous solvers and utilities and to write our own solver that is suitable for our desired problem, but a solid knowledge of physics and programming is needed. In this study, the interFoam solver is used, which is the solver for multiphase problems with incompressible fluids.