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New test and tune bench for Nano turbines from www.HAB.se

Old 12-10-2012, 12:28 AM
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Ian Davidson
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Default RE: New test and tune bench for Nano turbines from www.HAB.se


This is data from a stock Lambert T25 tested a couple of times during the year.

Kolibri T25 (exact same engine)
2650grams / 5.84lb @ 27C / 80F
2880grams / 6.34lb @ 10C /50F
3250grams / 7.16lb @ -3C /27F
Stock T25, or T25-HP ?

Old 12-10-2012, 12:41 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se


ORIGINAL: frema

Well i can say i knew it along that jetcat is fooling with the egt probe
i measure it too
they made a big mistake in the engine , but that is something different
i can understand that the t25 is much more powerfull because of the completely different chamber , but also the much bigger impellor and turbine
Martin did a very good job , and jetcat has a basic engine
thats how i see it
congrats on the testing , very nice.
ps, i tuned the juniors
2,3 kg is not bad heeee

Regards,
Martin.

Since 'Power = thrust x exhaust gas velocity'- and we're only measuring the thrust here, that alone is not enough to say one turbine is more powerful than another.I agree the exhaust gas velocity on all jets is so fast anyway that thrust is by far the most important factor to focus on, but it's only one component when it comes to 'Power'.

Could the thrust of the T25 and P20 be increased by slightly enlarging the diameter of the exit nozzle? This would decrease the exhaust gas velocity for sure, but would the thrust then not increase too?



Old 12-10-2012, 03:53 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

ORIGINAL: frema

Well i can say i knew it along that jetcat is fooling with the egt probe
i measure it too
Like the iPhone 4 signal loss issue when holding it "wrong", update the firmware to always show full signal = problem solved


ORIGINAL: frema

ps, i tuned the juniors
2,3 kg is not bad heeee

Regards,
Martin.
Is this from stock engines just adjusted or did you fit the larger compressor to these too?
Old 12-10-2012, 08:47 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

i put larger compressor in
Regards,
Martin
Old 12-10-2012, 11:30 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se


ORIGINAL: Ian Davidson


ORIGINAL: frema

Well i can say i knew it along that jetcat is fooling with the egt probe
i measure it too
they made a big mistake in the engine , but that is something different
i can understand that the t25 is much more powerfull because of the completely different chamber , but also the much bigger impellor and turbine
Martin did a very good job , and jetcat has a basic engine
thats how i see it
congrats on the testing , very nice.
ps, i tuned the juniors
2,3 kg is not bad heeee

Regards,
Martin.

Since 'Power = thrust x exhaust gas velocity'- and we're only measuring the thrust here, that alone is not enough to say one turbine is more powerful than another. I agree the exhaust gas velocity on all jets is so fast anyway that thrust is by far the most important factor to focus on, but it's only one component when it comes to 'Power'.

Could the thrust of the T25 and P20 be increased by slightly enlarging the diameter of the exit nozzle? This would decrease the exhaust gas velocity for sure, but would the thrust then not increase too?



I think it's the other way around. Smaller outlet will increase the power. Look at a fighter jet taking of, the tailcone is closed when throtteling up. I bet Frema has the correct answer :-)


Old 12-10-2012, 11:31 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se


ORIGINAL: frema

i put larger compressor in
Regards,
Martin
Cool. How much thrust did they make all stock?
Old 12-10-2012, 01:25 PM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

not much
all the jetjoe juniors i had , had only 1,3 kg
if you raized the temp ,with closing exhaust , then you get barrely get 1,5, not more
so this is an improvement for me, and i am realy happy about it
oke, its absolutely not the a t25 , but i dont have that turbine wheel , need 2 blades[]
Old 12-10-2012, 10:30 PM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se


ORIGINAL: frema

not much
all the jetjoe juniors i had , had only 1,3 kg
if you raized the temp ,with closing exhaust , then you get barrely get 1,5, not more
so this is an improvement for me, and i am realy happy about it
oke, its absolutely not the a t25 , but i dont have that turbine wheel , need 2 blades[]
Thats good progress and it sounds resonable as the Jr is a copy of the old Lambert T32 which also made around 1.5kg of thrust. In a year or two maybe we all say the Jr is a copy of the Frema hybrid ;-)
Old 12-11-2012, 01:20 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se


ORIGINAL: Henke Torphammar


I think it's the other way around. Smaller outlet will increase the power. Look at a fighter jet taking of, the tailcone is closed when throtteling up. I bet Frema has the correct answer :-)

A smaller diameter exhaust nozzle would cause the gasses to exit faster – i.e. the only way a fixed volume of gas can exit through a smaller aperture within the same timeframe, is if that gas is moving faster. If the power were to remain constant, then this increase in gas speed must come to the detrimental cost of thrust.
<o></o>
Just like a conventional propeller, Power = Thrust x Pitch-speed. If the Power remains constant, then for the Thrust to increase (by increasing the diameter of the propellor), the Pitch-speed must decrease (by decreasing thepitch of the propellor)

Everything in a gas-turbine is probably highly-balanced/matched though, so perhaps you can’t simply increase exhaust nozzle diameter without also changing something else, but nevertheless, the principle is right. :-)
<o></o>

Old 12-11-2012, 10:36 PM
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ORIGINAL: Ian Davidson

Just like a conventional propeller, Power = Thrust x Pitch-speed. If the Power remains constant, then for the Thrust to increase (by increasing the diameter of the propellor), the Pitch-speed must decrease (by decreasing the pitch of the propellor)
Yes, but a turbine doesn't make thrust as an EDF. You have to make the engine run well first. If you open up the tailcone pressure will drop, it's not obvious that the engine can produce power with less pressure. I'm not that deep in to it, but it seem if you close the cone pressure and temprature will rise and creating more power. You can how ever trade speed for static thrust by adding a thrust tube after the engine.
Old 12-11-2012, 11:57 PM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se


ORIGINAL: Ian Davidson

A smaller diameter exhaust nozzle would cause the gasses to exit faster – i.e. the only way a fixed volume of gas can exit through a smaller aperture within the same timeframe, is if that gas is moving faster. If the power were to remain constant, then this increase in gas speed must come to the detrimental cost of thrust.

thrust equals mass flow times velocity. At same mass flow by core engine, faster exhaust means always more thrust.

Gaspar
Old 12-12-2012, 12:47 PM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

Thrust equates to the mass of gas being displaced during a period of time (lets say 1 cubic metre per second).

But ‘Power’ is the product of this and the velocity at which that 1 cubicmetreof gas per second, is being propelled.

For example, to displace 1 cubicmetreof gas in one second through a drinking-straw requires far more power than to displace 1 cubicmetreof gas in one second through a drain-pipe, as the velocity of gas will be far higher.

In the video below, one guy is producing perhaps 80kg of thrust, but probably only 1500W of power, because thevelocityat which the gas is beingpropelledis so slow.

[youtube]http://www.youtube.com/watch?v=g3oUkyMae0c[/youtube]

<o></o>

Old 12-17-2012, 12:09 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

Hi Gaspar,

How far are you with completing your own Jets Munt nano-turbine ?
Any data available ?
I do believe you informed us at JetPower last year to come up with one having 3,5 kg of thrust ? Or did I misunderstand ?

Best,
Nicolas.
Old 12-17-2012, 07:39 AM
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ORIGINAL: SpiderJets

Hi Gaspar,

How far are you with completing your own Jets Munt nano-turbine ?
Any data available ?
I do believe you informed us at JetPower last year to come up with one having 3,5 kg of thrust ? Or did I misunderstand ?

Best,
Nicolas.
They showed it at Jetpower this year too. Not ready yet I was told, looked and felt the same as last year but they have bumped the thrust figure to 4kg. If they can make it P20 size/weight and put out 4kg of thrust at a resonable out door temprature it's in the game for the larger 90mm airplanes :-)

2:20->
[youtube]http://www.youtube.com/watch?v=vMa1USIlIic[/youtube]
Old 12-17-2012, 07:47 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

Wow! 60mm and 4kg - that looks very nice! Please put my name down for one!
Old 12-18-2012, 12:49 AM
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ORIGINAL: Ian Davidson

Wow! 60mm and 4kg - that looks very nice! Please put my name down for one!
We have yet to see it in action. Looks to have a larger inducer then the T25 Kolibri and a larger houseing so it should be possible. At jetpower 2011 I was told it should arrive before the flying season of 2012 and provide 3.5kg of thrust, which it did not. Either it's not prioritized or problems occurred. Looking forward to seeing it up and running.
Old 12-18-2012, 01:40 AM
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ORIGINAL: Henke Torphammar

ORIGINAL: Ian Davidson

Wow! 60mm and 4kg - that looks very nice! Please put my name down for one!
We have yet to see it in action. Looks to have a larger inducer then the T25 Kolibri and a larger houseing so it should be possible. At jetpower 2011 I was told it should arrive before the flying season of 2012 and provide 3.5kg of thrust, which it did not. Either it's not prioritized or problems occurred. Looking forward to seeing it up and running.

If it happens, it would be amazing, but like you say, let's wait and see. After all, I can claim to produce a 60mm turbine which outputs 5kg of thrust... unless someone wants to actually see it ;-)

Does anyone know what would happen were you to squirt nitrous-oxide into the induction of a jet engine? Could this yield short-term gains in thrust due to the extra oxygen?
<o></o>


Old 12-18-2012, 01:54 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

I think, not much would happen.
The ECU would restrict the max RPM anyway (in this case, by lowering the pump voltage and hence the amount of fuel feed).
Suppose there would not be a set maximum (hypothetically speaking), you would perhaps have higher RPMs, but most of all, a destructive exhaust temperature, causing rear BB failure.
If your objective would be a higher RPM, I think you'd better tweak the software to do so .

Perhaps injecting small amounts of water in the compressor (hence causing perhaps steam internally and higher thrust at same RPM), would serve your theoretical objective better.

Just my 2 c, and wild guess. I am not an engineer nor turbine expert, just some logical thinking.

Nicolas.
Old 12-18-2012, 08:41 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

hahaha
if you only knew what i know
you can do soooooo much more with nano turbines
lots more then the factories know
Old 12-23-2012, 03:17 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

We've tested the kerostart on the P20SX alot the past days. Focus has been on how hot it gets compared to gas start. Our tests show that it's much better then expected! We replicated the Ready2fly venom by monting a styrofoam stab in the same way as if fitted to the real venom and made several starts. It did work very well indeed, EPS is a great indicator of heat as it bubbles up directly. With the start sequence working as it should the stab was fine. It was even possible to hold your hand under the stab during the whole startup procidure.

We have not made the same static tests with the Kolibri and gas start as we have been flying that combo the whole summer with no problems.

Video will be up soon.

More testing useing FLIR later during the hollidays.

Old 12-23-2012, 03:47 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

Sorry for posting here, but this great threads seems to be accumulating some knowledgeable miniature turbine folk. :-)

My P20-SX has been out-of-action for a couple of weeks, as by accident I plugged a 4S (14.4V) battery into the ECU instead of the correct 2S (7.4V) battery. The ECU went bang (there was smoke!) and that was that. :-(One of the consequences after I blew-up the ECU, was that if you tried to power it up again, the starter motor would just spin without being instructed to by the transmitter.
<o></o>
I sent the ECU back to JetCat and they repaired/replaced it reporting that the PSU element had been fried. With the new/repaired ECU they returned however, although my P20-SX now trys to start normally, it fails with a “LOW RPM”. Please see the video below, it seems like either the RPM sensor is faulty, or the logic in the ECU which reads the RPM is faulty?<o></o>

Does anyone have any suggestions what I should check?

[youtube]http://www.youtube.com/watch?v=hARHQ_iuHy8[/youtube]
<o></o>



Old 12-23-2012, 04:45 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

oh thats easy
your starter is slipping
yo need to clean the oring or put new one in
Regards,
Martin.
Old 12-23-2012, 04:48 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

no rpm reading Ian
is the engine stuck? the rotor?
its defenatly the starter
Old 12-23-2012, 06:49 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

I always keep a can of break cleaner in my toolbox! It a great degreaser in a convenient spray can that solves the slipping oring problem. For these small engines the fuel fill cap is often close to the turbine and the smallest spill will ruin the day.

Make use to wait a good 15min before starting the engine so that the break cleaner evaporizes, else dooms day


Old 12-23-2012, 06:59 AM
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Default RE: New test and tune bench for Nano turbines from www.HAB.se

just what i always do

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