Wind tunnel simulation of the wind-breaking effect of “climbing plant－fence” composite sand barriers with different permeabilities

To explore new treatment technology measures for enclosed areas affected by wind erosion, wind tunnel simulation experiments were conducted to determine the wind protection effect of the “climbing plant-fence” composite sand barrier with different porosities (β). Experiments were conducted under 6, 8, and 10 m·s⁻¹ net wind conditions using model A (fence, β: 96%～98%) with four composite sand barriers: Model B (non-leafy stage, β: 59%～64%), model C (non-leafy stage, β: 50%～55%), model D (leafy stage, β: 40%～45%), model E (leafy stage, β: 30%～35%). The results show that: 1) The flow field structure of composite sand barriers of different types showed a “decrease - increase - decrease” trend, and there was a wind shadow deceleration zone on the leeward side of the barrier. The flow field structure in front and behind the fence was consistent with the no deceleration zones. 2) For different wind speeds, the average near-surface wind protection effectiveness of composite sand barriers in the non-leafy stage (models B and C) reached the lowest at a wind speed of 10 m·s⁻¹, at 18.55% and 18.38%, respectively. The leafy stage composite sand barriers (models D and E) had the lowest effectiveness at a wind speed of 6 m·s⁻¹ at 44.03% and 45.42%, respectively. The wind protection effect of composite sand barriers in the leafy stage increased with increasing wind speed. The wind protection effect of composite sand barriers during the non-leafy stage decreased with increasing wind speed. 3) The combination showed that wind protection can be achieved when the barrier is 59% to 64% permeable. Composite sand barriers provided better wind protection than did fences. Wind protection at the leafy stage of the barrier was better than that at the non-leafy stage. Within the measurable range, the protective distance was 0.6H～15H (H: height of the sand barrier, 1H = 15 cm) and 0H～15H for the composite sand barriers in the non-leafy and leafy stages, respectively. The effectiveness of composite sand barriers against wind was inversely proportional to the degree of permeability. Therefore, the “climbing plant-fence” composite sand barrier can improve the protection of the enclosed area and reduce the loss of surface material by wind action.