131 research outputs found
Application of FDS and firefoam in large eddy simulations of a turbulent buoyant helium plume
Large eddy simulations are conducted in the near-field region of a large turbulent buoyant helium plume. Such plumes are of relevance for fire safety research due to the similar flow features as in the buoyant (smoke) plumes above the fire source. The transient and mean flow dynamics are discussed with and without the use of a Smagorinsky-type subgrid scale (SGS) model. For this purpose, two different computational fluid dynamics (CFD) packages are used. Small-scale structures, formed at the edge of the plume inlet due to a baroclinic and gravitational mechanism and subject to flow instabilities, interact with large-scale features of the flow, resulting in a puffing cycle. This puffing cycle is recovered in the simulations. In general, the LES calculations reproduce the main features of the turbulent plume. Mean velocity results compare well with the experimental data. The mass fractions are overpredicted on the centerline though, and higher on the domain
Numerical simulation of an array of heaving floating point absorber wave energy converters using OpenFOAM
In this paper we use the CFD toolbox OpenFOAM to perform numerical
simulations of multiple floating point absorber Wave Energy Converters (WECs) in a
numerical wave basin. The two-phase Navier-Stokes fluid solver is coupled with a motion
solver to simulate the wave-induced rigid body heave motion. The key of this paper is
to extend numerical simulations of a single WEC unit to multiple WECs and to tackle the issues of
modelling individual floating objects close to each other in an array lay-out. The developed
numerical model is validated with laboratory experiments for free decay tests and for
a regular wave train using two or five WECs in the array. For all the simulations presented, a good
agreement is found between the numerical and experimental results for the WECs’ heave
motions, the surge forces on the WECs and the perturbed wave field. As a result, our coupled
CFD–motion solver proofs to be a suitable and accurate toolbox for the study of
wave-structure interaction problems of multiple floating bodies in an array configuration
Towards the numerical simulation of 5 Floating Point Absorber Wave Energy Converters installed in a line array using OpenFOAM
In this paper we use the CFD toolbox OpenFOAM to
perform numerical simulations of multiple floating point
absorber Wave Energy Converters (WECs) in a numerical wave
basin. The two-phase Navier-Stokes fluid solver is coupled with a
motion solver to simulate the wave-induced rigid body heave
motion. The purpose of this paper is twofold. The first objective
is to extend numerical simulations of a single WEC unit to
multiple WECs and to tackle the issues of modelling individual
floating objects close to each other in an array layout. The second
objective aims to include all the physical processes (e.g. friction
forces) observed during experimental model tests in the
numerical simulations. The achievements are verified by
validating the numerical model with laboratory experiments for
free decay and regular wave tests using a line array of two and
five WECs. For all the simulations presented, a good agreement
is found between the numerical and experimental results for the
WECs’ heave motions, the surge forces on the WECs and the
perturbed wave field. As a result, our coupled CFD–motion
solver proves to be a suitable and accurate toolbox for the study
of wave-structure interaction problems of WEC arrays.location: Cork, Irelandstatus: publishe
Verification of the accuracy of CFD simulations in small-scale tunnel and atrium fire configurations
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