KJ66 Conversies
- Topicstarter Gerald Rutten
- Startdatum
first test i reach 98k ..trust 11,5kg 487°c
then compressor fail....
the photo show different type of aluminium wheel
then compressor fail....
the photo show different type of aluminium wheel
Ooops.....:schrik:
I assume thats a cast failure?? 98K is very low, did you experience some surge just before? Engine running cool and good before failure. Hope nothing more is damaged.
Rgds,
Gerald
I assume thats a cast failure?? 98K is very low, did you experience some surge just before? Engine running cool and good before failure. Hope nothing more is damaged.
Rgds,
Gerald
first accelleration ramp was very slow, no hot spot and other
no damage ...only big imbalance after failure
the compressor debris touched the diffuser under compressor...but no damage
only bearing to change.. (now is noisy)
i see that last compressor is made in dark aluminium look instead light about previous one
the egt was stable from idle to 98k from 450° to 550° in acceleration
no damage ...only big imbalance after failure
the compressor debris touched the diffuser under compressor...but no damage
only bearing to change.. (now is noisy)
i see that last compressor is made in dark aluminium look instead light about previous one
the egt was stable from idle to 98k from 450° to 550° in acceleration
today another test ext. temp. 2°c
Laatst bewerkt door een moderator:
kj 66
very beautiful.
but i hear your bearings a little bit.
That,s nog good for the lifetime of your bearings
.
very beautiful.
but i hear your bearings a little bit.
That,s nog good for the lifetime of your bearings
.
many thx
there was noisy bearing used in other test engine... need to change with news when engine will be ok... no imbalance when running
there was noisy bearing used in other test engine... need to change with news when engine will be ok... no imbalance when running
working on another two diffusors
frees machine
Mooi Hobby bankje
Nice hobby tool
Mooi Hobby bankje
Nice hobby tool
Laatst bewerkt:
one of 5x machine of factory
the diffuser is made simply in 3x mode
the diffuser is made simply in 3x mode
because other machines are busy
this geometry is simply to made ...3x is ok...to work (only 2 tools used)
if the diffusor should be 2 stage design 5x machine is very useful
this geometry is simply to made ...3x is ok...to work (only 2 tools used)
if the diffusor should be 2 stage design 5x machine is very useful
A
ahmed atta
Guest
Dear Gerald,
i'm in my way to manufacture my jet and i need your help to buy bearing and turbine 85 mm
i'm in my way to manufacture my jet and i need your help to buy bearing and turbine 85 mm
Hi Ahmed, I use these turbine wheels: JETMAX | PRODUCTS | Turbine Wheels
and these ballbearings:
GRW - high precision ball bearings | Ball Bearings for model building
Best regards,
Gerald
and these ballbearings:
GRW - high precision ball bearings | Ball Bearings for model building
Best regards,
Gerald
hello...nice work... in my opinion ut160 must to be modified in the diffusor and CC
like FREMA indications
like FREMA indications
A
ahmed atta
Guest
hello,
How could i choose the best impeller Diameter corresponded with tubine diameter ??
and what is the parameters changes with the diameter of both ?
thanks
How could i choose the best impeller Diameter corresponded with tubine diameter ??
and what is the parameters changes with the diameter of both ?
thanks
Hi Ahmed, I don't do any calculations, mostly trial and error....
That said, diameters of both wheels should be same in most cases and works fine. However, when having a good engine with efficient NGV/turbine combination we can increase impeller diameter to max 106% compared to turbine diameter. This wil give some increase in power for the same engine diameter/weight. (With different reaction turbine we can go even further but that only gives more torque to the shaft, no more direct power, good for turboprop engines)
Here some comparison for a typical 80N engine with 66mm turbine wheel:
66mm = 84N thrust @ 120K rpm
68mm = 96N
70mm = 108N
70mm turbine wheel:
70mm compressor 140N thrust @ 120K rpm
72mm = 160N
74mm = 180N
Data above gained via tests, not calculated.
Hope this helps?
Best regards,
Gerald
That said, diameters of both wheels should be same in most cases and works fine. However, when having a good engine with efficient NGV/turbine combination we can increase impeller diameter to max 106% compared to turbine diameter. This wil give some increase in power for the same engine diameter/weight. (With different reaction turbine we can go even further but that only gives more torque to the shaft, no more direct power, good for turboprop engines)
Here some comparison for a typical 80N engine with 66mm turbine wheel:
66mm = 84N thrust @ 120K rpm
68mm = 96N
70mm = 108N
70mm turbine wheel:
70mm compressor 140N thrust @ 120K rpm
72mm = 160N
74mm = 180N
Data above gained via tests, not calculated.
Hope this helps?
Best regards,
Gerald