what is the right pitch change option?

Red Ember · November 2, 2016, 15:07

Hi to all!
Can anybody give me advice what is correct choice for rotor-stator interface if rotor blades number is twice more than stator vanes one? I suppose the stage model is the right choice, but is there any differences between automatic, value and specified pitch angles options? May be any snake in the grass?

P.S. About task: 7-staged axial compressor, turbogrid mesh, steady-state case.
Using stage/automatic angles options, the only robust solution was yielded by massflow&temperature at inlet and static pressure at outlet combination, although the result is invalid - high pressure values (about *1.5) and low efficiency (about /1.5)...

Red Ember · November 14, 2016, 03:45

Specified pitch angles option leads to solver fail every time. Only automatic one works relatively well, I don't know why.
BC combination p*in - p out leads to solver fail, hence I have to use Gin - p out.
If I find out something else, I jot down a comment.

November 2, 2016, 15:07	what is the right pitch change option?	#1
Red Ember Member Alex Join Date: Feb 2016 Posts: 81 Rep Power: 10	Hi to all! Can anybody give me advice what is correct choice for rotor-stator interface if rotor blades number is twice more than stator vanes one? I suppose the stage model is the right choice, but is there any differences between automatic, value and specified pitch angles options? May be any snake in the grass? P.S. About task: 7-staged axial compressor, turbogrid mesh, steady-state case. Using stage/automatic angles options, the only robust solution was yielded by massflow&temperature at inlet and static pressure at outlet combination, although the result is invalid - high pressure values (about *1.5) and low efficiency (about /1.5)...

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November 14, 2016, 03:45		#2
Red Ember Member Alex Join Date: Feb 2016 Posts: 81 Rep Power: 10	Specified pitch angles option leads to solver fail every time. Only automatic one works relatively well, I don't know why. BC combination p*in - p out leads to solver fail, hence I have to use Gin - p out. If I find out something else, I jot down a comment.