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| Titel |
Adaptive moving finite volume scheme for flood inundation modeling under dry and complex topography |
| VerfasserIn |
F. Zhou, G. Chen |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250059347
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| Zusammenfassung |
| To assess and alleviate the risk of flood inundation on local scale, the use of numerical
models with high accuracy, spatial resolution, and efficiency is crucial for the reliability of the
solutions to provide the forecasts and early-warnings of flood inundation at large or
meso-scales. Different with traditional numerical models on fixed meshes, an adaptive
moving finite volume scheme on moving meshes is proposed for flood inundation modeling
under dry and complex topography, this scheme aims to improve the predictive
accuracy, spatial resolution, and computational efficiency as well as the satisfaction of
well-balanced positivity preserving properties. The crucial feature of our scheme is to move
fixed number of unstructured triangular meshes adaptively for approximating the
time-variant patterns of flow variables and then to update flow variables through PDEs
discretization on new meshes. At each time step of simulation, this scheme consists of
three parts, giving in time n for instance: (1) adaptive mesh movement equation for
adapting vertex from xij(n, v) to xij(n,v+1) where v is the iteration step, this equation
can be transferred as Euler-Lagrange onesË--
(ÏË-x) = 0, in which the monitor
function Ï is determined by the solution and the gradient of solution; (2) geometrical
conservative interpolation for remapping flow variables from Ui(n, v) to Ui(n,v+1),
when ||xij(n,v+1)-xij(n, v)||-¤10-6 or v=5, then set xij(n, +-):= xij(n,v+1) and
Uj(n, +-):= Uj(n,v+1), and (3) HLL-based PDEs discretization for updating flow
variables from Ui(n,+-) to Ui(n+1,0), the treatments of bed slope source terms
and wet-dry interface are based on second-order reconstruction of Audusse et al.,
(2004) and Audusse and Bristeau (2005). Two analytical and two experimental
test cases were performed to verify the advantages of the proposed scheme over
non-adaptive methods. The results revealed two attractive features: (i) this scheme could
achieve high-accuracy and high-resolution shock-capturing of dam-break inundation
over dry and complex topography with computational cost as lower as possible;
(ii) this scheme could improve the capability of SWEs to handle non-hydrostatic
pressure problem by achieving streamwise meshes parallel with the spatial distribution
of time-variant streamlines. Therefore, adaptive moving finite volume scheme on
unstructured triangular meshes could be one of efficient and reliable choices for
simulating complex flow in flood inundation over dry and irregular topography. |
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