Forge burner orifice issues

[Awalker]

That is interesting. Essentially it is a venturi, so it is the same theory. The one thing I notice about all the "venturi" burners is that they only use half of the venturi. That is they only use the bell reducer half and not the exit taper. I have found a couple of venturi calculators online, but none that will let me play without a credit card! So I would like to do some pressure calculations to see what the best design would be on paper. From what I have seen the inlet side needs to have an angle of 60*ish then the outlet side should be 30*ish. It would be interesting to build a few different designs and play with a water manometer, or a flow table (like in the carburetor shops) to see what designs producer what pressures in the inlet, the vena contracta, and the outlet of the burner to have some real data on what burner is the best.

[MooseRidge]

Possibly, you can find something on this site....

Free online Mechanical Engineering calculators: Fluid Flow calculators, Hydraulic Calculators, Pressure and stress calculator

[Candidquality]

Might be able to use some of the information on pulse jet design. Obviously we don't want explosion, but some of the same principals apply.

[Zsartell]

I've built more than a few Pulse Jets and have found that even a poorly designed venturi can make or break an engines ability to even run. The better the venturi, the better the flow and the better the engine will run. It's the same basic idea.

You might get a kick out of this:

Large Pulse Jet Engine Attached To Go-Kart = Crazy Video - Metacafe