Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Mar 26, 2021 7:52:19 GMT -5
Hi Everyone, I have finally make out time for my next turbine build and wish to to discus it here. I was interesting in Axial turbine but due to cost and other factors I have decided to go with radial turbine. check out this article on a mixed flow turbine. www.hindawi.com/journals/ijrm/2012/589720/ can a mixed flow Turbine oppose the axial force generated by a centrifugal compressor wheel in our engine? can someone easily upgrade his engine with ball bearing without issues? am taking my time to choose the best turbine wheel form my use. thanks.
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Post by racket on Mar 26, 2021 16:35:15 GMT -5
Hi Chuks
Nope , a mixed flow turbine wheel doesn't have any more disc than a radial .
Ball bearing upgrades are possible , but as Patty has found out with his engine , its not straight forward , you can wreck a number of parts getting things right .
The "best" wheel is the one I gave you a Link to in my PM reply .
Cheers John
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Mar 26, 2021 17:18:59 GMT -5
Hi Chuks Nope , a mixed flow turbine wheel doesn't have any more disc than a radial . Ball bearing upgrades are possible , but as Patty has found out with his engine , its not straight forward , you can wreck a number of parts getting things right . The "best" wheel is the one I gave you a Link to in my PM reply . Cheers John Thanks John will post some pics of compressor and turbine wheel. that link will be considered for another build maybe after this one.
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Mar 26, 2021 17:32:32 GMT -5
there is an old wise men quote: 'gas turbine gets its highest fuel efficiency at full throttle' now question for the wise men, is that applicable to variable diffuser and NGV gas turbines? or are they just varying different full throttle? I mean do they design the engine with different design parameters and just vary them?
my questions may sound a bit out of engineering terms but since its for the wise people they will have a way to understand.
thanks
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Post by racket on Mar 26, 2021 20:37:28 GMT -5
Hi Chuks
It depends on how the engine is designed, BUT ,..... you know I love BUTS ,...... but generally full throttle has the highest PR so more expansion , similar to a higher compression ratio piston engine , more expansion means more energy extraction and generally a better fuel efficiency.
BUT .....also theres a temp limit vs PR consideration , lotsa variable to consider .
Cheers John
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