Study on windbreak performance of tree canopy by numerical simulation method

Abstract

When airflow fly over trees, a shelter area will be generated at downstream area, and wind speed in the region will be reduced correspondingly. In order to analyze the windbreak performance of tree canopy, porous media method and additional source term are explored to simulate by computational fluid dynamics. Based on the given method, windbreak performance of trees with different canopy porosity, canopy shapes and distances between trees is investigated in detail, and characteristics of wind flow on the downstream of tree are shown. Results showed that small canopy porosity does not always mean good performance of windbreak, especially for the lower part. Canopy shapes only affect wind speed in the wake range. In these regions, windbreak performance of tree depends on the thickness of canopy. When distance is beyond 3H (H is the height of tree), wind speed becomes uniform at the downstream of tree and spacing can be equivalent to the porosity. But, for the region close to tree, trees with spacing cannot provide effective windshield. These simulations of tree canopy windbreak performance are conducted. All the results of the new model show better canopy flow characteristics through the field.

Advances in CFD Modeling of Urban Wind Applied to Aerial Mobility

“…The standard k − model is inefficient when solving complex three-dimensional flows, such as the one arising in urban environments, due to the onset of strong pressure gradients and flow separation [23]. As an alternative, many authors prefer the realizable k − model [24], which makes some of the closure coefficients become functions of strain rate and rotation rate. In this way, it allows for a consideration of the impact of the flow rate of deformation; thus, it is more flexible.…”

Feasibility analysis using a porous media model to simulate the wind protection effect of windbreak forests

“…The porous media model reduces the modeling and computational complexity in the numerical simulation of vegetation wind protection effectiveness. (Jian et al, 2018; Osama & Saud, 2021), and the plant's canopy is usually considered a porous medium with a given porosity (Taleb & Mays, 2021). A drag source term representing momentum depletion was added to the Navier ‐ Stokes equation to characterize the flow resistance provided by the canopy to simulate the effect of porous structure on the free‐flow characteristics.…”

The design of tall windbreak panels: Design issues and a case study

“…1(b)), in agriculture for production protection ( Fig. Windbreaks can be manmade structures, but trees can also be used (4). 1(d) and (e)) (1), and generally to change local environmental conditions and improve leaving, production and environmental conditions (2) (3).…”

“…1(d) and (e)) (1), and generally to change local environmental conditions and improve leaving, production and environmental conditions (2) (3). Windbreaks can be manmade structures, but trees can also be used (4). The effect on wind flow is complex and depends on several parameters, the land geometry, the height of the windbreak, and the material used, which can be porous and can partially permit the wind to pass through to reduce the wind force.…”