free-air flow

例句：

1. 1. The wind carries the scent of the forest into our free-air flow.
   风把森林的香味带到我们的自由空气流动中。
2. 2. The free-air flow helps to cool down the room.
   自由空气流动有助于冷却房间。
3. 3. In a free-air flow, the particles move in random directions.
   在自由空气流动中，粒子以随机方向移动。