A 3D fluid model has been developed to simulate streamer discharges in unsteady airflow. The model couples the drift–diffusion equation for charged particles, the Navier–Stokes equations for air, the Poisson’s equation for the electric field, and the Helmholtz equation for photoionization. It allows us to study electrical discharges at different timescales defined by light and heavy particles and to investigate the effects of unsteady airflow. The model treats the time integration in an implicit manner to allow longer time steps, which makes the simulation of long-duration discharges feasible. Moreover, the model uses an unstructured mesh allowing the calculation around solid bodies with complex geometries, and uses adaptive mesh refinement to lower the computation time. The validity and accuracy of the model has been verified by comparing its results with published results, which compares simulations in steady air from six different streamer codes. Our results are consistent and among the most accurate in terms of charge conservation. In order to investigate the influence of wind on streamer discharges, we present results from simulation of a long-duration discharge, in which two successive positive streamers are initiated from a positive polarity electrode in presence of a transverse airflow. This simulation shows that the impact of airflow on positive streamers is driven by the ions, and therefore the airflow effects are seen in ions timescale. Interestingly, we observe that the positive streamer channel, while tilting in the direction of the wind, remains attached to the surface of the electrode. The subsequent positive streamer emerges from the charges remaining from the initial streamer, which have been moved over the electrode surface toward the trailing edge. This mechanism shows and explains the clear tilting of the successive positive streamers in the direction of the wind.

已经开发了 3D 流体模型来模拟不稳定气流中的流注放电。该模型耦合了带电粒子的漂移-扩散方程、空气的 Navier-Stokes 方程、电场的泊松方程和光电离的亥姆霍兹方程。它使我们能够研究由轻粒子和重粒子定义的不同时间尺度的放电，并研究不稳定气流的影响。该模型以隐式方式处理时间积分以允许更长的时间步长，这使得长时间放电的模拟变得可行。此外，该模型使用非结构化网格，允许围绕具有复杂几何形状的实体进行计算，并使用自适应网格细化来降低计算时间。该模型的有效性和准确性已通过将其结果与已发表的结果进行比较来验证，该结果比较了来自六种不同拖缆代码的稳定空气中的模拟。我们的结果是一致的，并且在电荷守恒方面是最准确的。为了研究风对流光放电的影响，我们提供了长时间放电模拟的结果，其中两个连续的正流光在横向气流的存在下从正极性电极开始。该模拟表明气流对正流光的影响是由离子驱动的，因此气流效应在离子时间尺度上可见。有趣的是，我们观察到正流光通道在向风的方向倾斜时，仍然附着在电极表面。随后的正流注从初始流注剩余的电荷中出现，这些电荷已经在电极表面上朝后缘移动。这种机制显示并解释了连续的正飘带在风向上的明显倾斜。