suction from ambient
 

Dear All,

I have a case where Ihave a small fan in a pipe and I do know the flow rate when the "system" is in still ambient air and entrains the flow from the ambient. But what happens if it was placed outside and there would be a wind speed approaching the inlet of the pipe. Would the flow rate change? and if so how could I include it in my calculation? Thanks in advance. Regards Soren