Kelly W

My Feedback: (2)

Hi Guys,

A good friend of mine is looking at building a UT-160 turbine from plans with an Albisser wheel/NGV set.

http://www.ut160.de.tl/Home.htm?PHPS...71ada20ac5a228

The effort and complexities in building a turbine are very well known here, so what I'm looking for is a little feedback on the design. As in, what kind of thrust does it really produce, any improvements justified in the design, how long will the chamber last, etc, etc? Please reply, or PM me if you like, with whatever feedback have so I can pass it on. Who knows, I may even be interested going old-school and getting my hands dirty again if it works out for him!

Thanks,
Kelly

chrigui

i'm building two of these...

see here

http://www.toflyrc.com/Forum/tm.asp?m=213212


regard's
Christian

www.webalice.it/jetflydemoteam

chrigui

New diffuser

Kelly W

My Feedback: (2)

Wow Christian, you do very nice work.

It looks like you are experimenting with 2-stage vs. helical diffusers. Is the engine based on a helical diffuser or is that your own work, since the one on the CNC looks like a 2-stage? Interesting that the floor of the primary vanes is flat, where is use to be a small taper on the KJ's and all the derivatives I've taken apart over the years. The diffuser and combustion chamber design share a number of features with engines I've seen apart before.

When do you expect to be running it? Any time soon?

Kelly

chrigui

many...thx..

i hope to finish the engine aroun christmas...i'm very busy at work with cnc machine

Christian
www.webalice.it/jetflydemoteam

LN-JET

I guess what you call helical diffusor is what the Germans call Vollkeil ( full wedge) diffusor.
The last version of the UT has this design. I got the drawings at Jetpower, and have spent some time comparing them to other
engines. The trumpet shape of the burners is somewhat unusual, and he has gone through much work to make tools to crimp the tubes
to the rear chamber wall, where others just solder or weld.
The lubrication tubes to front and rear bearing looks a bit old fashion, like early KJ.
The injectors are front mounted, like the Graupner G-booster. May be service friendlier?
It seems like Ulrich has no background in turbomachinery, but have just used available sources and formulas, and his mechanic common sense to construct
this engine. Maybe that is good enough? At least he has decent CAD skills.
At the rate chruigi is producing parts, we will soon know how well it goes!
And by the number of compressor wheels, I hope one of them will be put on a long term full power test?:-)

Lars

Wayne22

My Feedback: (2)

Does that mean that the rebuild is done???

****

Other than the diffuser, it looks pretty conventional...does it offer any advantages over what is already availalbe??

chrigui

i have not "crimp" the tube like design...and i weld the tube with "spot welder" in my factory

chrigui

i don't know if i will made front injector or rear injector...
i think that 2 lubrication tube (one in front of compressor bearing and one in front of the turbine bearing) is
not a bad idea...but require little work than one tube in front of compressor bearing

Kelly W

My Feedback: (2)

Wrong friend Wayne, its Watkinson this time...

Theoretically speaking, the helical diffuser simplifies the airflow, eliminating the losses associated with the exit off the primary vanes and the entry into the secondary vanes. For example, this is one reason why a P-70 sounds different that a P-80, even though they are remarkably similar engine designs. This style of diffuser also allows the air flow to follow a larger radius as it changes from radial to axial, which must pay back in terms of efficiency as well. Next time you have a chance to look at a KJ style 2-stage diffuser, just consider how fast the air is moving and how incredibly small that radius is...

Kelly

Kelly W

My Feedback: (2)

Christian

If I decide to go for it as well (aw man, that was way too quick to reach this stage of thought...), since you clearly have the resources I wonder if you'd be interested in manufacturing a chamber or two? Yours look fantastic! Are they all stainless, or partially inconel sheet? What material spec does the design call for?

This isn't an offer, but keep it in mind...


Oh, one more question... What's the maximum diameter of the engine overall? I'm curious if it could be shoe horned into a HotSpot? [>:]
Kelly

chrigui

kelly...

now i build the turbine like a prototype and i made 2 or 3 chamber for test...(i don't know if they work well or not) and i
made then in stainless 0.5mm thickness..but if they work well i made in inconel steel
the compressor are garrett 024
the flame tube are in inconel...

I think that the turbine will run good to help you with spare part...(i must work on other diffuser for Urlich Thiel...but i had a car accident and the work was delayed)

the diametere is the same of P80 jetcat or all kj66

Ulrich Thiel

Hi Christian,
I'll be happy that you are thinking at my diffusor system!

Regards Uli

chrigui

ola...Uli...

i have 5axis cnc very busy (is the machine most used in factory)
i have the Anticorodal aluminium ...very strong to made the diffuser

Ulrich Thiel

Hi Chris,

I can see that you would like to use my outer cone with a inner one. I told you that doesen't work.
I'f got a new design for that.

What do you think? When can I get the diffusor system?

chrigui

Yes i remember i must to modify....i use your cone and i made a little cut around border to open or close the diameter...(like other my engine)
If you have no time to wait i can ship my diffuser but is not finished because i will finish it during assembly...

Ulrich Thiel

I have time. I'm busy with my L 39.
But I need the diffusor to complette my next UT160-ZA for this L39. I think I need it by the end of November.
Is this possible?
For the lubrication of the bearings: You can also use one pipe to the front bearing. In this case you should increase the airflow in the tunnel.
I have drilled 3 holes with a dia of 2 mm in the diffusor and the tunnel like the enclosed pictures.
Otherwise the endbearing wil be to hot.

LN-JET

Hallo herr Thiel!
Nice to have the designer himself on the forum.
I bought a set of your plans at JetPower08, and they look very nice.
I also have a set of plans from A. Kittelberger, and I am trying to decide which one to make.
What exactly is the thought behind the conical outlet of the sticks?


Lars

Ulrich Thiel

Hi Lars,

the conical outlet decrease the airspeed at the outlet of the sticks. The flame will be stabilized at that point.
This is important for the high acceleration rates of the modern turbines.
If you can live with moderate acceleration rates it is not necessary.
I visited A. Kittelberger in Hamburg and we have spoken about that point.
The disign of the holes ist the same like the design from A. Kittelberger.
The chamber works very well.

Uli

chrigui

i hope to try for the end of november to built 2 diffuser

ps..what is the problem about your cone? the exaust diameter is 64,2mm...the lenght is 26mm

Ulrich Thiel

I have made a mistake as I roll the end to the dia 64 mm. There is a bevel from the tool that I use.
The turbine is pumping with this cone. I think there is delamination of the airflow at this edge.
I don't know the exact reason for that, but it's defenatly from this cone. Another one works perfect.

chrigui

Is this different diameter?

Ulrich Thiel

Yes,
you have this on the inside, too.

chrigui

i try to "repair" your cone

Gerald Rutten

Hi, I also have seen both drawings and both are looking very interesting. Just out of curriosity, when Jesus Artes enlarged the compressor for the JG100 design they enlarged the shaft from 14.5mm to 16.5mm as I also made on my KJ mod., maybe overkill, I don't know how to calculate kritical resonance rpm which was the case for the modification. Now I noticed that Alfred's engine also has a thicker shaft but the UT engine has a thickness of only 14.5mm while still using the larger impeller. I reckon this was calculated and is safe to use?

Rgds,
Gerald

My JG100 rotor;