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sivarama1 March 21, 2009 04:23

convergent_divergentnozzle
 
i am also simulating convergent and divergent nozzle,
1) In CFX-11,Two region of flows how should analysis actually,take
convergent and divergent nozzle (in convergent is subsonic and
divergent is supersonic)
1)subsonic
2)supersonic
in two region in single model (that means convergent and divergent
nozzle in a single geometry in that in that i will give boundary
condition inlet of convergent pressure 15 bar steam, throat of
pressure 8 bar outlet of 1 bar pressure)
i know inlet velocity of steam 856 m/s this is saturation steam.
How will analysis in CFX-11,as a hypercritical point of correct
results came,but i should verified in CFX-11 SOFTWARE analysis,please
let me know.
once again thankyou for replay.
,i am sending .rar file,please verify it,
in that CFX,and ICEM files.
Actually i done same process,but solution not converging
Geometry:combined of convergent and divergent nozzle.
Converging and diverging nozzle flow problem
My doubt,this model i was created in UNIGRAPHICS modeling
software,meshing ICEM CFD,
when ever i am giving analysis:at that time some problem is there
step2:Boundary condition
Fluid :Steam
mass flow rate:0.5 kg/s
at inlet of convergent nozzle:subsonic condition a)pressure=10
bar;Temperature:356 m/s
at outlet of Divergent nozzle :a)supersonic condition .
You told this type of settings and simulations given by tutorial 8
from ANSYS CFX release 11.0. in this different : inlet is supersonic
condition outlet also supersonic condition
but my point of view inlet is subsonic and outlet is supersonic condition
1)i was increased mesh size
2)That flow direction changed
3)Fluid:Dry steam taken
4)Same boundary conditions
But does not converging(up to 200 iterations converging),what i am
thinking know up to convergent portions was converged.after that it
is not converging,)
convergent nozzle:solution converging .
Divergent nozzle:solution not converging as per velocity plot.and pressure plot.
Actually pressure should drop and velocity should increases.but in
this condition;
1)convergent to throat :velocity increases and pressure droping
2)Throat to Divergent nozzle:Velocity not increasing and pressure not droping.
What is the problem. i am thinking Two solutions(means subsonic and
supersonic condition will not give in single solution) that is correct
or not,please verify that.
Thank you very much.
__________________
sivaramakrihnaiah


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