Wind machines are increasingly used to mitigate spring frost damage in agricultural sectors. Complementing quasi-3D temperature measurements to quantify the warming effects of wind machines (Dai et al., 2023), this study develops a numerical model to quantify warming effects on air and plant tissues and resolve the dynamic interplay between turbulent rotating plumes and canopy structure. We implement an integrated model in a large-eddy simulation and validate the model against field observations. Simulation results show remarkable agreement with the air mixing and warming effects observed during wind machine operation in Dai et al. (2023). Simulation results reveal significant air and leaf warming near the wind machine due to direct jet-mixing. Beyond 20 m from the machine (3–4 rotor diameters), while wind velocities drop rapidly, the warming is sustained and gradually decreases over distance. This sustained warming, without direct jet mixing, likely results from the advection of jet-entrained warm air. The warming extends 150 m upstream and 550 m downstream, influenced by the background wind. This difference is attributed to the interaction between the machine-induced jet and the background wind, forming convergence patterns when jets oppose the wind and extended warming plumes in wave-like patterns when jets align with the wind. Cross-stream warming symmetrically extends about 250 m. Within these warming regions, leaf temperatures closely follow air temperatures due to strong turbulent heat exchanges. Outside the warming zone, radiative cooling prevails, bringing the leaf–air temperature difference back to approximately 1 degree. These findings collectively give new insights into interactions between the induced warming plumes and air flows within the canopy and provide a useful tool to optimize operational wind machine deployment. This integrated model uniquely provides a full, multi-process representation of outdoor reality with respect to wind machine operation in orchards.

中文翻译：

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集成大涡模拟，用于模拟果园冠层风力机引起的植物组织变暖


风力机越来越多地用于减轻农业部门的春季霜冻损害。为了补充准 3D 温度测量以量化风力机的变暖效应（Dai 等人，2023），本研究开发了一个数值模型来量化对空气和植物组织的变暖效应，并解决湍流旋转羽流和冠层结构之间的动态相互作用。我们在大涡模拟中实现了集成模型，并根据现场观察验证了模型。模拟结果显示与 Dai 等人在风力机运行期间观察到的空气混合和升温效应显着一致。 （2023）。模拟结果表明，由于直接喷射混合，风力机附近的空气和叶片明显变暖。距离机器 20 m（3-4 个转子直径）之外，虽然风速迅速下降，但变暖现象持续存在，并随着距离的增加逐渐减弱。这种持续变暖，没有直接喷射混合，可能是由喷射夹带的暖空气的平流造成的。受背景风影响，变暖范围向上游延伸150 m，向下游延伸550 m。这种差异归因于机器引起的射流和背景风之间的相互作用，当射流逆风时形成汇聚模式，当射流与风对齐时形成波状模式的扩展变暖羽流。横流增温对称延伸约250 m。在这些变暖的地区，由于强烈的湍流热交换，叶子温度紧随气温变化。在变暖区之外，辐射冷却盛行，使叶片与空气的温差恢复到大约 1 度。 这些发现共同为引起变暖的羽流与冠层内气流之间的相互作用提供了新的见解，并为优化运行风力机部署提供了有用的工具。这种集成模型独特地提供了有关果园风力机运行的室外现实的完整、多过程表示。