"Cooling Fan Manufacturer" flow from the "base" hidden level "blades" into and filled in the "outlet" of the cavity, when accumulated to a certain extent it will exceed the normal atmospheric pressure outside the body cavity, so he formed "wind. "Cooling Fan Manufacturer" narrow rear end of the front generous "cavity" will force the internal airflow towards the rear end of a broader movement of the cavity, constantly "mutual squeeze" the air last only from a small slit (ie, "the wind Office ") in the" leak "out. "Cooling Fan Manufacturer" After continuous operation for some time, this structure can be gradually increased air pressure, resorted to vent air gap faster flow.