Oblique jet exit

[Sparweb]

I'm thrashing about for a way to deal with a "jet" that emerges from a plate at an oblique angle. The air flow is conducted to the manifold with hoses and fittings with an ID of about 0.28". It then arrives at a tube that is welded to a flat plate at a 15 degree angle. The exhaust hole is now elliptical. Normally one would expect a jet like this to be attached tangent to the radius of the turbine, but not this time!
The jet of air impinges on an axial-flow turbine. I am sort-of reverse-engineering the turbine, which I can handle, but the flow coefficient at this port keeps coming out >1! The objective of the project is to insert a flow restriction in the air supply line to keep the turbine from overspeeding.

Thanks in advance for the help you can provide. Please bear in mind that I'm a structural eng, so I'm full of stupid questions.

In case you want some more numbers, P=75-80 psi, D=0.28", rho=0.20 lbm/ft^3.


STF

 

[martindup]

SparWeb,
Your problem sounds like something I studied in post grad flow dynamics. It is all a haze but this is what I remember. It was about the effects of a nozzle spraying fluid tangently into static fluid. It was solved using the Navier-Stokes relations. Theoreticly if you were to ease down on the simplifying of the N-S relations to account for a non-tangently flow intrusion and a non static fluid being sprayed into you will solve the problem. But solving the simple tangently and static problem was a hairy affair so you might be bussy with your problem on that route for the next couple of years. I would suggest getting someone in the know with CFD-simulation and turbine blades and pay them to simulate the thing. A couple of universities all over the world has some project running on CFD simulations of turbine blades.
Martin

 

[Sparweb]

Since the first post, I've had time to dig into the thing further, and the exit to the nozzle isn't the biggest problem we face. The economics just tipped the other way.

Thanks anyway!


STF