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arXiv · 2207.07210

High-resolution large-eddy simulations of simplified urban flows

Marco Atzori·Pablo Torres·Alvaro Vidal·Soledad Le Clainche·Sergio Hoyas·Ricardo Vinuesa
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Abstract

High-fidelity large-eddy simulations of the flow around two rectangular obstacles are carried out at a Reynolds number of 10,000 based on the free-stream velocity and the obstacle height. The incoming flow is a developed turbulent boundary layer. Mean-velocity components, turbulence fluctuations, and the terms of the turbulent-kinetic-energy budget are analyzed for three flow regimes: skimming flow, wake interference, and isolated roughness. Three regions are identified where the flow undergoes the most significant changes: the first obstacle's wake, the region in front of the second obstacle, and that around the second obstacle. In the skimming-flow case, turbulence activity in the cavity between the obstacles is limited and mainly occurs in a small region in front of the second obstacle. In the wake-interference case, there is a strong interaction between the free-stream flow that penetrates the cavity and the wake of the first obstacle. This interaction results in more intense turbulent fluctuations between the obstacles. In the isolated-roughness case, the wake of the first obstacle is in good agreement with that of an isolated obstacle. Separation bubbles with strong turbulent fluctuations appear around the second obstacle.

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Marco Atzori, Pablo Torres, Alvaro Vidal, Soledad Le Clainche, Sergio Hoyas, Ricardo Vinuesa. 2022-07-14. High-resolution large-eddy simulations of simplified urban flows. https://arxiv.org/abs/2207.07210

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