Numerical simulation of a flow over and through porous layers of large porosity
نویسندگان
چکیده
In this talk we present a continuum model and numerical results for transient flows over and through porous media. First, we briefly discuss the derivation of the model and present an algorithm for its numerical treatment. Subsequently, we present results from direct numerical simulations for developing flows over porous layers of large porosity. Due to the steep velocity gradients across the interface between the porous layer and the clear fluid, a KelvinHelmholtz instability is onset that leads to the formation of a vortex-shedding shear layer after sufficient time. Important characteristics of this layer such as growth rate, selfsimilarity and statistics of the fluctuating velocities are discussed. Finally, we present results from a parametric study with respect to the porosity of the medium. This study has potential applications in the simulation of forest fire spread, in which the vegetation is modeled as a continuum porous medium. Keywords— Porous media, Kelvin-Helmholtz instability, shear layers, flow over vegetation.
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