hydro nozzle

[MVIDSMITH]

I am in college in a cnc class and have the availability of a lathe, shaper, welders and cnc milling machines. I have constructed a small crossflow turbine and now need a nozzle design. can anyone help. the wheel is 2.35 inches wide, 12.27 inches in diameter made of .25 steel plate  and has 18 blades cut from 1/5 sections of 4 " steel pipe.

  i  will be attaching a picture soon.

Mark

[Nando]

The nozzle ( tongue) that a standard Crossflow is hydro dynamic (like an airplane wing) that is difficult to make.

There are other arrangements to accomplish the same thing but not in continuous basis, instead the flow is controlled in steps, like 1 / 4, 1 / 3, 1 / 2, 3 / 4.

The width of the cross flow is small, so let me ask, what is the power that you are generating ?.

Also, are you having problems with the water volume and need to adjust the volume due to water level restrictions ?.

Inform and may be we could offer different solutions to your problem.

Regards

Nando

[MVIDSMITH]

this is the hydro honda turbine. I have a constant volume of water in a 2 inch pipe that doesn t fluctuate much through out the year because it is spring fed. I am looking for a fixed design for now and will probably move to something more complex later. Right now; if you ll pardon the pun; this is my first project and iam just getting my feet wet.

mark

[Nando]

The nozzle design depends on the water volume and the width and the radius of the turbine.

Also, the head of the water source to determine the water velocity that gives the area of the Nozzle.

I am including a sketch of the Nozzle dimensions and a photo of a plaster of Paris form to make a small Nozzle with fiber glass epoxy.

So supply the info I may be able to assist you.

Regards

Nando

[Nando]

Please explain what is a Hydro Honda turbine.

The drawing I included needs to be defined for your turbine once you inform water and head values.

Regards

Nando

[Vtbsr]

Hello nando, I was looking at your plaster mould and i had a question. It looks like you have extended the final point of the plaster to far, as compaired to the drawing that looks like the standard nozzel for a crossflow. I thought you wanted a smooth arc right into the outside dia. of the crossflow. I think the 2" penstock for this project will be undersized for the width ,he must have a head of 50 to 100 ft. Need more info

[Nando]

The nozzle is about like the schematic with the exception that the edge of the tongue is as close as possible to the radius of the turbine.

It may be that the photo does not show the whole "affair" and the angle and white color is "fooling" you.

The drawing says 1/8" clearance and that is wrong, it should be as close as possible to reduce the water losses, We have obtained 1/32 or better.

There is another consideration that has to be paid careful attention, the necking of the nozzle to the exit Nozzle area should be with greater area than the Nozzle area to maintain maximum water velocity.

The Nozzle area is defined by the inside edge of the Nozzle (next to the Turbine) as shown in the drawing as the straight line of the Nozzle and the Neck width and length of the Nozzle, and the skirt (tongue) always kept, as close as, possible to the radius of the turbine.

I hope that this helps.

Nando