Water flow through a cone questions?

[allblowdup]

I have a cone that has an opening 6.125 15" long and an exit of 3.100. The center lines of the inlet and outlet are not the same and the outlet is at a 15 deg upswept angle. I have been trying to come up with the best shape that I can in order to move water through this at inlet speeds of 90 mph. The only things that can't be changed are the angle of the nozzle,the inlet and oulet sizes, and the center line of the inlet/outlet.

 

[allblowdup]

The origanol design.

 

[btrueblood]

Is that a 2-D model? It seems to be missing the swirl component due to the 15 degree flow angle change.

 

[btrueblood]

FWIW, you are on the right path, using gentler flow transitions to try and keep the flow as smooth as possible. You might consider turning vanes to reduce the inevitable swirl. Both ideas don't require CFD to envision.

 

[allblowdup]

Thanks, Ya its just a 2d model. The cone is round. It is a jet boat race nozzle. The pressure applied to the inlet side is fixed(roughly 200 psi). What I am using is just a simple cfd program that I don't think really can show much detail.

 

[racookpe1978]

Good shape - it looks clean and more efficient at speeding up and re-directing flow.

OK, so the inlet must be circular and at its present position, orientation (perpendicular to the CL) and diameter. Your re-design is much smoother and better, but you still have an inflection point in the middle.

Can you begin the inflection point of new curved "top" of your 2d figure so the bend begins right at the inlet itself?

 

[allblowdup]

I can although infront of the inlet is outlet of the pump. If i start the inflextion there I will have a sharp change of direction at that point. I figured a longer sweeping curve would be better. I will try it and see what happens. Thanks

 

[allblowdup]

Tried it but really didn't see much change. Another idea I have is if I was to have the last three inches of the oulet go from being oval to round. This would allow me to get a gentle curve without having to have the secondary curve closer to the inlet. I not sure if there are issues having an orfice go from oval to round.

 

[btrueblood]

"not sure if there are issues having an orfice go from oval to round. "

You need to look at the wall profiles along both axes of the oval. Any steep/rapid expansion can cause separation.