Hi all, We are trying to build a venturi and I have got a couple of questions. I am not an engineer actually, and I am working together with 2 mechanical engineers who graduated and forgot everything long time ago :) We are trying to build this venturi to collect hazelnuts from the ground. I don't think we have built the best we can do, so I thought maybe you guys can help me. The hosepipe has to have at least 100mm crossection and 10 meters length. This is the only "must" we have. You can check out the drawing and understand it better. The hosepipe is the one on the right side. The fan is blowing from the bottom pipe and forces the air goes left which eventually creates a pressure difference. How can I do the math of this thing? I thought of giving an angle to the bottom pipe, because I think air loses its speed when it has an exact "T" shape. Some ideas? I would be grateful if you help me. I don't think I could explain very well; but hope you will understand.