引导气流 meaning in English

steering current
steering flow

The brakes are cooled by ram air lead in by a light composite duct
由轻量化材料制成的导管引导气流以冷却刹车。
Mean 500 hpa geopotential height for july 2002 . the red arrow shows the direction of the steering flow for tropical cyclones
二零零二年七月500百帕斯卡的平均位势高度，红色箭咀为热带气旋引导气流的方向。
Mean 500 hpa geopotential height for the months of july from 1961 to 1990 . the red arrow shows the direction of the steering flow for tropical cyclones
一九六一至一九九零年七月份500百帕斯卡的平均位势高度，红色箭咀为热带气旋引导气流的方向。
However , in july 2002 , the subtropical ridge did not extend to southern china and the steering flow over the northwest pacific had a more northerly direction than usual . as a result , the tropical cyclones in the region were carried northwards and did not enter the south china sea (
但今年同期副热带高压脊并没有西伸至华南，使西北太平洋上引导气流的方向比正常偏北，在该区的热带气旋因此偏向北移，而不向西进入南海（