I am just another dummie and have a problem. Would be happy, if anyone could help me out. The task is to design a system of ai flow of 200 km/h in a 2,5 - 4 m wide tube (vertical). That specific project is related to my hobby, and my knowledge accordign to physics is minimal. What I would like to get from you is some kind of formula with wat I can calculate the needed measures of ventilator giveing generated wind speed, , rotation speed, diameter(or smth) and mat be the width and angle of blades. In short: How to design the ventilator knowing only wanted air speed, diameter and rpm-s? Is it even possible?

Viljar

This sounds like an application for a very large fan. 200 km/hr in a 4m dia. duct is approx 1.5 million CFM (cubic feet per minute). In order to design any ventilator / fan you will also need the pressure requirement. There are classical design methods for designing fans (text by Eck) both axial and centrifugal. Is what you are trying to make a windtunnel? Sounds like with such a large volume you'd want to design an axial flow fan. The text by Eck should be able to help you out. Its titled Fans; design and operation of centrifugal, axial-flow, and cross flow fans by Bruno Eck. I believe it may be out of print though. Your best bet might be to call some large axial fan manufacturers.

good luck

[v_h_memar]

Hi dear sam
I am looking for Fans by Eck but I do not find it up to now. do you have this book ? I need to a graph in this book. please help me if you can
thanks.
v.memar