Most efficient convergent nozzle

[T C]

I want to know what's the most efficient type convergent nozzle available now at present. I means what's the shape that is most efficient for a convergent nozzle. By efficiency, I want to mean that the inlet velocity to throat velocity ratio will be as close as possible to the throat area to inlet area ratio.

 

[russ_watters]

I want to know what's the most efficient type convergent nozzle available now at present. I means what's the shape that is most efficient for a convergent nozzle. By efficiency, I want to mean that the inlet velocity to throat velocity ratio will be as close as possible to the throat area to inlet area ratio.

Wellllll...for incompressible flow, all nozzles must meet that criteria due to conservation of mass (continuity).

And for compressible flow, the velocity ratio and area ratio are by definition unchained.

So the question doesn't make a lot of sense to me, but for most of your questions the answer of a De Laval nozzle should suffice.

It would probably be better, though, to specify what you are trying to do - what fluid and conditions you are looking for, entering and leaving, and engineer your device from there.

 

[jim hardy]

This book has a good chapter on how to design them for steam using a Mollier chart.

I suppose the principles would apply to other compressible fluids.

Another good reference for steam, but harder to find, would be Salisbury's classic

https://www.amazon.com/dp/B0042GKXMI/?tag=pfamazon01-20

old jim

 

[cjl]

Convergent nozzles tend to be pretty efficient, though if you're running a compressible fluid with a high(ish) mach number, your velocity ratios and area ratios won't match due to compressibility effects. What's your application and why are you so concerned with nozzle efficiency?

 

[jim hardy]

If you're measuring flow
in my plant , for feedwater flow we used a converging-diverging Venturi tube made to ASME standards.

To best of my memory It had a discharge coefficient of 0.995 so was pretty doggone 'efficient' .
That measurement we used to calculate the reactor's power production so we wanted it accurate - even applied corrections for local gravity.

See ASME's book "Fluid Meters"
https://www.asme.org/products/books/fluid-meters-theory-application-sixth

here's an overview ,
ftp://ftp.unicauca.edu.co/Facultades/FIET/DEIC/Materias/Instrumentacion%20Industrial/Instrument_Engineers__Handbook_-_Process_Measurement_and_Analysis/Instrument%20Engineers'%20Handbook%20-%20Process%20Measurement%20and%20Analysis/1083ch2_29.pdf

in my circles that ASME book is "The Bible": .

 

[JBA]

ASME configuration nozzles are extremely efficient i.e.>.99% of the theoretical flow for gases. The below document has both nozzle configuration dimensions and a discussion related to their accuracy.

http://www.fmcltd.uk.com/flow-nozzle-asme-ptc6.php

 

[jim hardy]

The below document has both nozzle configuration dimensions and a discussion related to their accuracy.

What a great reference !
Thanks !

 

[T C]

Thanks to everybody for their contributions.