confusion in specifying domain flow direction and results

ashwani.thakur · February 26, 2015, 01:59

hi,
i m doing a problem on steam flow across a rotor blade

at inlet i have used the flow direction as normal to boundary condition, but how can i provide an angle for steam flow at inlet ( picture attached)

also in results for velocity, i m getting a vortex or reversed flow kind of situation across fluid domain, is there something wrong or it is ok ( picture attached)

thankyou

ashwani.thakur · February 26, 2015, 02:01

domain picture

ghorrocks · February 26, 2015, 05:21

I see lots of major issues:

* You appear to be modelling the blade as a solid region. You do not need to do this unless you intend to model heat transfer in the blade. Most people model blades as a hollow in the fluid domain. Refer to the tutorials for how to set this up.
* Your top and bottom boundaries do not appear to be periodic boundaries. Refer to the tutorials for how to set this up.
* You will get massive separations if you run the device far from its design operating point. But only worry about this point after you have fixed up the other two points.

ashwani.thakur · February 27, 2015, 11:29

thanks for replying
i m actually doing heat transfer analysis with initial cond's:
total temp: 425 C, total pressure: 17 bars
outlet cond's: 14 bar ( static temp)

ghorrocks · February 28, 2015, 07:45

OK, if you are modelling heat transfer in the blade then model the blade as a solid body.

But the other two points still hold.

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February 26, 2015, 05:21		#3
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	I see lots of major issues: * You appear to be modelling the blade as a solid region. You do not need to do this unless you intend to model heat transfer in the blade. Most people model blades as a hollow in the fluid domain. Refer to the tutorials for how to set this up. * Your top and bottom boundaries do not appear to be periodic boundaries. Refer to the tutorials for how to set this up. * You will get massive separations if you run the device far from its design operating point. But only worry about this point after you have fixed up the other two points.

February 27, 2015, 11:29		#4
ashwani.thakur New Member ashwani Join Date: Feb 2015 Posts: 15 Rep Power: 11	thanks for replying i m actually doing heat transfer analysis with initial cond's: total temp: 425 C, total pressure: 17 bars outlet cond's: 14 bar ( static temp)

February 28, 2015, 07:45		#5
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	OK, if you are modelling heat transfer in the blade then model the blade as a solid body. But the other two points still hold.