Urgent answer attempt version 1.0


Hi Adrian,
I think you have to look at the area of the duct too. A 4" distance would be a decent amount of space for a 3" diameter tube to flow through, but a 6" tube would be closer to the back wall than it is wide. Look at the space between the end of the port and the back wall as an exit orifice. Say your port was 4" away and 4" in diameter. That is a 50 sq inches of orifice between the end of the duct and the wall. The port has an area of 12.5 so you have some room. A 6" port would have an area of almost 30 so it might start to see 50 inches as a restriction. I don't know enough to go deeper into this and I am sure there are issues created by the velocities, masses and elasticities involved that I cannot figure, but you can see where I am going with this.

Thomas


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