T04 Turboshaft Build

[racket]

Parts are looking good :-)

[mitch]

Those swirls/vanes look pretty sweet

[thescreensavers]

Well Its been a while since I have posted, project is coming to an end and everything was successful.

Have hit 20PSI with 950ish EGTs but hose popped off and havent pushed it since, need it to survive until final presentation and RPM sensor is funky at the moment.



I have a 10k resistor pulling up the output of my Omron E3X-A11 sensor,  the value of the resistor might be too high, so going to try a 2.2k tomorrow which was a recommendation from Omron Techsupport.  I have tested the Arduino RPM reading with a function generator which matched the output of the sensor.

First Fire up, wires are a mess also fried my arduino(another story)... last minute wiring tons of fun! hah, had a rich start on this, turn on annotations for info.

www.youtube.com/watch?v=n3l67DDBJRw


We also tried to see how low we can get it to idle, got it to hit 0.65psi-0.75spsi at ~20k RPM. This either means too big of a combustor or good combustor performance, probably a bit of both  ,  EGT was rising, most likely due to bypass being mostly closed,

Oil temp sensor was not working here so why it reads negative, and RPM is accurate until 60k rpm but above it gets funky(repeatable),

Nothing gets red hot, hottest we found the outer liner to be was 250F where the flame front is.

www.youtube.com/watch?v=dCx6-dYR79Q


Ardiuno coding has been simple but frustrating but got it done, once its finished I will post it up for everyone.

Here is my Wiring Diagram.

www.dropbox.com/s/qj16oso0cw26ek9/ed2-ver2.pdf?dl=0

More later

[racket]

Hi

I'd be a tad concerned about your P2 reading at 0.65 psi at 20K , thats extremely low rpm and pressure for that sized rotor , generally temps would be very high as the engine struggles with low comp/turb efficiencies , did you try accelerating the engine from that low point ?

You can get into hung start territory at anything below ~3 psi P2 unless a warm engine and oil , its dangerous and potentially damaging to the engine to try very low P2 stuff , you're getting away with it because of your lowish TOTs and lack of backpressure , but you will get caught eventually , play safe and keep ~5 psi for an idle , temps will be lower.

Engine build is looking neat :-)

Cheers
John

[thescreensavers]

Dec 7, 2015 21:38:40 GMT -5 racket said:

Hi

I'd be a tad concerned about your P2 reading at 0.65 psi at 20K , thats extremely low rpm and pressure for that sized rotor , generally temps would be very high as the engine struggles with low comp/turb efficiencies , did you try accelerating the engine from that low point ?

You can get into hung start territory at anything below ~3 psi P2 unless a warm engine and oil , its dangerous and potentially damaging to the engine to try very low P2 stuff , you're getting away with it because of your lowish TOTs and lack of backpressure , but you will get caught eventually , play safe and keep ~5 psi for an idle , temps will be lower.

Engine build is looking neat :-)

Cheers
John

Thanks! Watch the second link we do some high speed/low speed stuff, we did a 1.44 psi to 15psi acceleration, sounded good.  

engine sounds good and has no issues running at 2-3psi, EGTs are ~900ish. The oil was warmed up and over 40psi. Youll hear me complain about the high EGT temps.. haha

This was just for fun playing around, the idle speed/run speed will be set with solenoids, so it will be completely controlled through arduino. 


Thanks for your concern I will make sure to have the idle speed/run speed run a bit higher psi.  But Since I do not have an RPM sensor for the free power and there is no load I do not want to spin it too fast for the "run solenoid" so the idle might get set low.