RE: GR130
 

Here as promised the pictures from the turbinwheels....
Easy to see the huge differences

Best regards Lukacs

RE: GR130
 

Great the RCU forum is back alive together with the pictures<div>
</div><div>Regards</div><div>Lukacs
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</div><div>
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RE: GR130
 

I had some progress. I turned the needles as in the Kittelbergers design and measured the flow. Not easy to measure always some water spilled over...cool in every syring is the same amount of water :) if it's not spilled over

here the pics

RE: GR130
 

As a next, I tried to add an O- ring for the diffusor cover. But that's not working because the gas can is to short. So I tried to create a sealing ring out of silicone. After some tests I got it to work as requested.
The assembling of the cover for the diffusor is important otherwise the compressor will touch the compressor cover
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RE: GR130
 

Who can help me with the connection of the GlowPlug on the Hornet Projet ECU.there are 3 cables coming out of the box: RED / YELLOW /BLACKThe Black and Red are probably for the starter Motor. The Yellow for the Glowplug... But where do I have to connect the ground for the Plug?Thanks for your answersRegards Lukacs

RE: GR130
 

yellow = glow plug
red-black = starter motor

RE: GR130
 

Hey Crhrigui Thank you. That's what I wrote...But where do I have to connect the ground for the Glowplug? Regards Lukacs

RE: GR130
 

One of two wire connected to starter must to be connect to turbine "ground/common" also.

it's the red wire

RE: GR130
 

connection

RE: GR130
 

Hi Chrigui
Thank you for your great help, appreciate that!

Attached two new pics...

1. Assembled and almost ready! And 2. sh... happens. I bored the holes at the wrong position. Maybe I can fix it with a ring out of POM with some silicone. Or does someone else has a goo idea?


Best regards Lukacs

RE: GR130
 

do you must to fix egt sensor? or you must to fill hole?

RE: GR130
 

Hi Chrigui
sadly I bored all mounting holes wrong [X(]

So I going to try to create a ring from POM (Polyacetal) and put some silicone on it and try to cover the holes with this ring and then I will mount on this ring the EGT Sensor too

Regards Lukacs

RE: GR130
 

you can fill with a screw, or with castolin or silver solder

RE: GR130
 

Well a screw is not so good because under the hole is the flow of the air coming out from the diffusor......and that will create lot of turbulence

But Silver solder maybe a good idea...Will try that on an other old can

regards Lukacs

RE: GR130
 

Hi Lucaks, I had something similar in the past, fitting a new diffuser with different hole pattern. With a scissor I cut 4 5x5mm plates of 0,3mm ss sheet and simply spotwelded them carrefully over the holes, works for more than 6 years on my old KJ66's. You can always make a new casing later on.

Rgds,
Gerald

RE: GR130
 

Hi Gerald,
We recently did a CFD on the GR180 comp/diffusor. Graph Above.
The sharp dropoff is where the system chokes.
Andre

RE: GR130
 

Hi Andre
That sounds very interesting? Can you write a little more to your documentation?
Regards Lukacs

RE: GR130
 

Hi Lukacs,
This work was done as part of a project I support for our local university mechanical engineering dept.
This work was part of a Msc students study. We instrumented an engine to verify the CFD prediction vs real measurements.
The results proved that the methods and software used was indeed very accurate.
Another student designed a new compressor for an improved pressure ratio vs massflow.
Its about 75mm dia with TT presure of 4.4.
(We know that 6 is possible with 400N - 600N in a 110mm dia case.
This was achieved in the USA for UAV using a mixed flow compressor.)
This has been manufactured and is about to be tested in an engine together with an optimised diffusor.
The next step is an improved combustor using CFD and test rig work.
We also have a student working on an improved turbine wheel and NGV.
Results have been very good despite the lack of funding from Government.
Fiddling with micro turbines is a very good source of experience for young engineers I found.
My reward is to see some progress in my own obsession with these wonderfull toys of ours.
Andre

RE: GR130
 

Hi Andre
Poahh, amazing! Thank you for sharing. Is it possible to get access to these documentations?
Or can you place some pictures?
Regards Lukacs

RE: GR130
 

Hi Lucacs,
Most of the docs are long and detailed with math and engineer speak. But I took this screenshot of the solid model of the first compressor and diffusor they came up with.
We hope to have it running in a few weeks.
BRG
Andre

RE: GR130
 

very nice work!

RE: GR130
 

Very nice work what your students are doing, Andre!

I became a fan of spot welding. Thank you Gerald for your hint

Regards Lukacs

RE: GR130
 

Attached some picture of my test bench

Regards Lukacs

RE: GR130
 

Hi Andre, very nice work, very honored you used my engine for these calculations. I just do some trial and error and see how it goes ha ha ha! Not sure although how to read you file. I see the choke intruduced when increasing mass flow while I understood that happens when I decrease (restrict) mass flow, hence increase total pressure up to a stage where the diffuser stalls. How should I interpret your graphs?

Best regards,
Gerald

RE: GR130
 

Hi Lukacs, nice test bench. Good you solved the mis-aligned holes issue.

Rgds,
Gerald