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arXiv · 1903.03521

The transport and deposition of heavy particles in complex terrain: insights from an Eulerian model for large eddy simulation

Scott T. Salesky·Marco G. Giometto·Marcelo Chamecki·Michael Lehning·Marc B. Parlange
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Abstract

The transport and deposition of heavy particles over complex surface topography by turbulent fluid flow is an important problem in a number of disciplines, including sediment and snow transport, ecology and plant pathology, aeolian processes, and geomorphology. This article presents a framework to simulate the transport and deposition of heavy particles over complex surfaces using the large eddy simulation (LES) technique. An immersed boundary LES code is coupled with an Eulerian particle code that solves the advection-diffusion equation for the resolved particle concentration field. The mass conservation equation for the particle phase is discretized in a finite volume framework using a Cartesian cut cell method that reshapes finite volume cells intersected by the immersed boundary surface and conserves mass accurately. The proposed numerical model is compared with data from wind tunnel experiments of heavy particle deposition over topography and is found to have good agreement with observed deposition patterns. An LES case study of snow deposition over idealized topography leads to several new insights. Particle inertia leads to relative velocities between the particles and fluid in regions of mean flow acceleration, thereby enhancing deposition on the windward side of obstacles and suppressing deposition on the leeward side. In addition, it is found that the mean components of particle inertia are a factor of 6 or more larger than the turbulent components, indicating that the enhancement/suppression of deposition by topography can be modeled in terms of mean flow quantities.

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Scott T. Salesky, Marco G. Giometto, Marcelo Chamecki, Michael Lehning, Marc B. Parlange. 2019-03-08. The transport and deposition of heavy particles in complex terrain: insights from an Eulerian model for large eddy simulation. https://arxiv.org/abs/1903.03521

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