Finally ... Project about to get started

racketmotorman · Post by **racketmotorman** » Sat Apr 14, 2007 11:15 pm

Hi Dennis
Lots of variables in turbine design :-((
.... so the final throat area of your NGV set will probably be found by trial and error .
If the area is too large you'll need to run the engine "hotter" to compensate , if the area is too small you can send the engine into surge , it has to be somewhere in the middle so that the compressor flows in an efficient range .
Just what size will depend on component efficiency (comp and turb), mass flow , turbine blade width , T I T 's , etc that you wish to run .
But could be more than comp wheel outlet area (perhaps 10% more) , but please be very careful how you measure this area and exactly where it is in relation to the turbine wheels inlet tips , radial distance will change "things" .
The best way to be certain is to draw the NGV set to scale on paper and measure the actual flow area at the NGV throats , thicknesses of vanes will influence angles and flows .

Please reread some of my earlier emails :-))

Cheers
John

Rossco · Post by **Rossco** » Sun Apr 15, 2007 12:15 am

Hi Guy's
John, Dennis and others interested.
If you can come up with some dims i would like to draw up these in Pro-E if i that would help.
I can measure volume, areas, CG and countless other things that i havnt played with yet, such as mechanical stress analysis.
Its about as close as i can afford to building a turbine, so i would be happy to give some input.

Rossco

Ash Powers · Post by **Ash Powers** » Tue Apr 17, 2007 5:21 pm

Rossco,

I'd be more than happy to take you up on this. I put together a spreadsheet some time ago to calculate the required NGV throat area for my current T04 GT build and have only been able to calculate the throat area of the actual NGV with some degree of guesswork given that the vanes are coming in at an angle and the thickness of the vanes at the throat area is different because of this.

IF you are interested, let me know - I can send over the dimensions of everything.

Bounce · Post by **Bounce** » Tue Apr 17, 2007 8:31 pm

Thanks to you guys above

@racket: Almost made a "little" mistake by confusing + and - 10% to comp.
Thanks for the correction. Will do a corrected concept now.

@rossco: Would surely be interesting to see how everything behaves...
Just tell me what dimensions you need and you'll have them as soon as I measured them/figured them out.

@ash: I would for sure be happy to have a little look at the dimensions of your GT. I'll be making the NGV a little other than yours, but having the dimensions of a running turbine would surely help me figureing out the approximate dimensions.

Can't wait for friday to come spending a few hours in the workshop again.

So long, Regards Dennis

Rossco · Post by **Rossco** » Thu Apr 19, 2007 8:30 am

Hey,
Bounce, Send me what you have now, and i can start on it. I am no expert whatsoever on turbines, so your going to probably have to explain a lot along the way. "how everything behaves" is probably a little optimistic! I can only draw up a 3d version, which is then capable of being measured in any way that you can think of with the program. How it behaves is up to you im afraid! Your understanding, design and build.

Ash, sure, send it through! As usual i will have to work out how to do up the compressor wheel... this is a real tricky spot, as i cannot find any good info or design drawings for them. So far, i have drawn them straight of the top of my head, with a little help from a drawing or two.
If you could take some set distance photo's from a couple of different angles it would be good. As well as any known/measureable dims. I could work it out from there.

Send it to the email add. set here, or give me a yell on any of the messenger progs, also listed here.

Rossco

Bounce · Post by **Bounce** » Thu Apr 19, 2007 2:12 pm

Hi Rossco

I'm not that good at drawing, but will post some dimensions and stuff here as work progresses. Still have to calculate and work out a few things.

Bounce · Post by **Bounce** » Sat Aug 04, 2007 3:29 pm

So finally I found time to build on and post something...

The compressorplate together with the tools I used making it (a little blurry)

Look down on the stator plate. One of the vanes is a little bit ugly/damaged due to a lazy builder, but should be ok

Compressorwheel inserted

Turbine section in early state of building

All in all nothing off the rail, but the best I could achieve with the tools I have at hand

So long, regards Dennis....

Johansson · Post by **Johansson** » Sat Aug 04, 2007 7:39 pm

Did you make that diffusor with nothing but a rusty iron file? Nice work anyway.

Damnit, we have more projects going on here in the turbine forum than the trumpet guys over at the valveless forum! Respect!

//Anders

Bounce · Post by **Bounce** » Sun Aug 05, 2007 2:05 pm

Hi Johansson

I used the lathe to make the basic style and the used an iron saw and file to bring it into shape. Had cost me several sawing blades and the file was brand new before using it. Seems that SS is quite tough or at least tougher than the crap a normal hobbyist can buy in Germany ;)

So long, (hopefully) more to come soon, Dennis

Ash Powers · Post by **Ash Powers** » Sun Aug 05, 2007 4:34 pm

Dennis,

Excellent work! Nice to see the quality of work you are putting into these bits. :)

I've been working a lot lately on a turbine calculator spreadsheet for use with my TV94 turbofan project and have come a LONG ways with it. I pretty much have the entire document completed, covering all of the design parameters for the diffuser, NGV, freepower stage, and a ducted fan output analysis. I'm not sure where you stand on your NGV calculations, but I could probably be of some assistance to you there. If you want to send over the info on your compressor wheel and turbine wheel, I will be able to give some input.

Here's a screenshot:

Bounce · Post by **Bounce** » Tue Dec 25, 2007 7:22 pm

After a quite long time I finally came to build a few new parts...
Nothing spectacular though, but another step to finishing the project hopefully within the next year...

CC inner and outer wall, almost finished

NGV plate half finished

NGV with guiding vane plan inserted

CC outer wall fitted to NGV

Quite a way to go, but the next update is (as I hope ;) ) to come soon.
Seems like it's going to be a quite heavy and, because of the reverse flow setup, big engine, but until it works properly weight and space are of secondary interest to me ;)

Regards, Dennis

Ash Powers · Post by **Ash Powers** » Fri Dec 28, 2007 1:14 pm

Hi Dennis,

Coming along nice and smooth. I'm really looking forward to seeing your build of the PAL-based design. Keep up the good work!

-Ash

www.pulse-jets.com

Finally ... Project about to get started

Theory engine

Sounds like I've got a plan now

Dimentions

Dims

long, long ago...

little update...