4|
Szabó et al.
Period. Polytech. Civ. Eng.
natural frequency and the
damping values are in good
agreement. The applicability of TMD during construction
stages was also proved, which is practically meaningful.
4 Aerodynamics of the bridge deck
The aerodynamic parameters were simulated by utilizing
open-source code OpenFOAM (version 9). The Komárom
Bridge deck section was considered both at construction
stage and after competition with the additional elements,
such
as the asphalt layer, curbs and handrails installed.
The computational domain used in the two-dimensional
simulations can be seen in Fig. 8. The domain sizes were
determined based on recommendations found in literature
in order to keep blockage ratio low.
In Reynolds-averaged models (RANS), the Navier-
Stokes equation together with the continuity equation are
averaged over time (denoted with overbar), resulting in
averaged equations according to Eqs. (3) and (4).
t i
j j i
i
j j i
j i j
u u u
p
u
u u
1
' '
(3)
i i
u 0
(4)
The averaging leads to new unknowns (
u u
i j
' '
), which are
referred to as the Reynolds-stresses due to velocity fluctua-
tions. In order to close the equations, turbulence models are
needed to introduce. The widely used
k–
ε equation turbu-
lence model was selected due to its simplicity and low com-
putational demand. Despite the fact, that vortex shedding
problem can best be handled by the computationally more
costly
turbulence models, e.g., LES,
k–
ε model can still
be used for fully developed turbulence around bluff bod-
ies [8]. Unsteady simulations were used in accordance with
the unsteady nature of the vortex shedding phenomenon.
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