11/127 manned flight engine.

[racket]

Hi Scott

Yep , you're spot on , I found the unit had been set to maximum , duh :-( ..............I must have accidently set it whilst reinstaling the engine .

24 V pump testing on the cards for today , just a single pump unit should surfice , I'll hook it up to the 24V starter pack , I do have a 24V PWM unit, from the 12/118 development, that I could use , I'll see what I can come up with :-)

Cheers
John

[racket]

Hi Scott

Now we've got some guts in the pump , its screaming a bit , but she'll flow 7,800 ml/min through the injectors at 80 psi supply pressure , previously with 2 X 044 pumps I could only get 4,300ml/min at 76 psi with the dump closed , with the single pump on 24V theres still more to give as the dump wasn't closed ..............LOL, or even close to closed :-)

Another test run in order methinks

Cheers
John

[slittlewing]

Excellent, fingers crossed for your next run then!! 😈
Hope fuel is cheaper in aus than it is here at the moment 😂 fuelling jet engines got expensive quickly haha!!

Cheers
Scott

[racket]

Hi Scott

Yep , fuel prices are up :-(

Petrol was at $AU2.02 the other day when I filled the test stand tank , thats ~1.13 Pounds per litre .

LOL..............I'll have to be quicker with the testing ;-)

Cheers
John

[wannabebuilderuk]

Mar 17, 2022 17:37:41 GMT -5 racket said:

Hi Scott

Yep , fuel prices are up :-(

Petrol was at $AU2.02 the other day when I filled the test stand tank , thats ~1.13 Pounds per litre .

LOL..............I'll have to be quicker with the testing ;-)

Cheers
John

Currently ~£1.60/litre for petrol here in Scotland, up to £1.80 for motorway stations

[racket]

OUCH !!!

[slittlewing]

Haha yeah £1.70ish at a branded fuel station near me and £1.60 at supermarkets. Annoyingly kero (home heating fuel) was 44p a litre this time last year and is now £1.10 🤦‍♂️I’m sure this spike will pass though.. given enough time!

Cheers

Scott

[racket]

Hi Guys

Full throttle test this afternoon , things got a bit "heated", it ain't gunna be pretty when I open her up :-(

youtu.be/-FcRNtsDZ30

youtu.be/kjFFjNbsC-I

Cheers
John

[andym]

Nice work John.... was that about 250lbs.... going to be epic with the afterburner  

[racket]

Hi Andy

I think the afterburner trials will be a while away , things don't look good when I examined the turb wheel , bits missing , I think I came up against some "limits" :-(

Thrust was good , but I don't know if I'll get that 250 lbs with the current setup , its as though the turbine stage runs into a power production problem once past a 2 Bar P2 , its requiring temperature rise rather than pressure drop to produce power .

At least the fuel supply issue is sorted :-)

Thankfully I have a spare turbine wheel to use , but I'll need to have a re evaluation of a few things , hopefully the flametube has performed OK , it'll be interesting to see what it looks like tomorrow .

There'll need to be several more viewings of the videos and some number crunching .

Cheers
John

[praendy2203]

Hi John,

I think there is more damaged than the turbine wheel.

Something happend to the cc, or the vaporizers.
The temps are too high after 3 Bar peak reached until shut down.
The gauges say good bye, so the tubes are molten.

Maybe the turbine wheel is too much "opened"
for producing torque for the comp wheel.

I hope you can fix it step by step😐

Andy

[slittlewing]

Hi John,

Unfortunate test, but I guess you knew you were sort of "playing with fire" based on the previous TOTs / testruns with small bursts at >2.5 P2!

Hope there is not too much damage and you find the problem, look forward to seeing your next steps to get the old girl at full power with cool temps

Cheers

Scott

[racket]

Hi Guys

She's pulled apart , some pics






















Flametube is OK and appears to be working nicely with combustion starting right at the front wall

Turbine wheel and NGV are a little worse for the experience

Exducer shroud has "accretions" which will hopefully be able to be easily removed and the part reused .

After having a chat to Andy M we came to the conclusion that maybe trialing a standard turb wheel without exducer clipping might be worthwhile even if flow is reduced just to see what the extra exducer angle/deflection has on performance .

At least I know whats required to be fixed , ................LOL, even if I don't really know how I'm going to achieve it

A classic case of over temp/speed with tips being thrown off .

Cheers
John

[pitciblackscotland]

Hi John,
you gave it the stick in the last vid Yeah the NGV is sick looking, do you have enough Inconel

Cheers,
Mark.

[racket]

Hi Mark

LOL.......I haven't even thought about the job of fixing the NGV , I'm still in the stage of trying to understand why the engine hits a "barrier" at ~2 Bar P2 .

The NGV outlet static pressures have made for some interesting number crunching , it appears as though I'm only getting an ~1.33 PR in the NGV , this is a lot lower than expected , so I've got some thinking to do .

The comp inlet static pressure gauge is indicating nearly a 20 Kpa - 2.9 psi pressure drop at 4:1 PR , that represents a pretty high flow speed into the comp wheel inducer , more calcs tomorrow to workout how much air and where its going , maybe a heap of it out the surge slot, don't know , but I'm having "fun??" exploring all the posibilities .

There was damage done , but I also gathered a lot of info , so taken all round , I think I'm ahead , especially with the flametube , if it survived that , it'll survive anything :-)

Sometimes we've just gotta be "adventurous" and take those extra steps even when we know they could be "unwise" ;-)

Cheers
John