High speed water through an orfice question?
High speed water through an orfice question?
(OP)
Trying to decide on a nozzle design. Right now we are using a 650 hp engine to move 4000 gal/min through an orfice that is 3.080 in Dia. Rough pressures are variable but are in the 200-250 area. The nozzle I have right now is 14" long and tapers down from the pump outlet od of 7" to the 3.080. It is in a racing jet boat so we are using the exhaust stream for propulsiom. My question is I can have the inside of the 14" long tapered nozzle smooth or I can cut rounded grooves in it with the direction of flow. The pump is a combination axial/centrifical design and does have a straightning ssytem on its outlet although the water is still spinning somewhat upon exit.
Mark
Mark





RE: High speed water through an orfice question?
If water swirl is an issue for you then I would try a cross set of vanes in it and then just try it out or rig up a small test version.
Not sure what exactly you're trying to achieve or modify / improve though.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: High speed water through an orfice question?
RE: High speed water through an orfice question?
Have you ever thought about using standard piping components? Type "pipe reducer 16.9" into google images - there isn't a 7" version but there is 8" and 6". Also you can buy formed elbows long radius and just cut to whatever angle you want. Weld it up then grind off the internal weld bead? They come in all sorts of metals.
Reducer is maybe a little short, but is smooth radius.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: High speed water through an orfice question?
http://services.eng.uts.edu.au/~phuoc/docs/writing...
The Ornel pump units were powering jet boats way back when Adam was a boy, worth doing some research on the Ornel jet pump boats, from memory the pump units may have been called "Squid"
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: High speed water through an orfice question?
RE: High speed water through an orfice question?
Regards, Ray
RE: High speed water through an orfice question?
Ted
RE: High speed water through an orfice question?
I guess another way of looking at it would be.
Having a divergent cone 14" long with the large end 7" and the small end being 3.100" would the cone be more effecient at moving water through it at 200 psi inlet pressure with a smooth inner surface or with a grooved surface in the direction of flow. Both having a swirl factor to the flow.
RE: High speed water through an orfice question?
Ted
RE: High speed water through an orfice question?