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Outlet Boundary Condition for the cone of a turbine

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Old   May 25, 2013, 06:22
Default Outlet Boundary Condition for the cone of a turbine
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Yaser
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hi dear friends

i'm modeling a cone (only) for the inlet of the turbine power, with ANSYS FLUENT 12. (the order of part: compressor+combustion chamber+cone+turbine)
i have the inlet mass flow rate, static pressure and static temperature, but have no data for the outlet of the cone.
if i choose the pressure outlet boundary condition, it ask me the pressure and back flow temperature, but i have no data about them.
T=640 C, P=95psi and mass flow rate is 80lb/s, Mach number is about 0.4.
please help me.

thank you.
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Old   May 26, 2013, 00:33
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Quote:
Originally Posted by Barzanoni View Post
hi dear friends

i'm modeling a cone (only) for the inlet of the turbine power, with ANSYS FLUENT 12. (the order of part: compressor+combustion chamber+cone+turbine)
i have the inlet mass flow rate, static pressure and static temperature, but have no data for the outlet of the cone.
if i choose the pressure outlet boundary condition, it ask me the pressure and back flow temperature, but i have no data about them.
T=640 C, P=95psi and mass flow rate is 80lb/s, Mach number is about 0.4.
please help me.

thank you.
Hi, Barzanoni. I have the same question as you.

I am doing my undergraduate thesis now. My modeling is simulating Fixed-Bed heterogeneous reaction. I need to set outlet boundary conditions, because I choose Eulerian Multiphase Model, I must select pressure-outlet for mixture and the gas phase and solid phase.

In tutorial of FLUENT, there is such an example which is about Eulerian Granular Flow and Heat Transfer. It suggest us choose the same temperature as inlet for both phases. But my problem involves reaction, until now, I have no idea about the species setting.

Hope to continue discuss with you.

Expect other people to join us.

All the best
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Old   May 26, 2013, 02:34
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Hi Liufeng

i think if the flow stream is supersonic, it is no matter that u set real value for pressure and temperature, and it is suficient to determine real order value. the below text is from Fluent tutorial:

Note: The momentum settings and temperature you input at the pressure outlet will be used only if flow enters the domain through this boundary. It is important to set reasonable values for these downstream scalar values, in case flow reversal occurs at some point during the calculation. (p 12-12, Fluent Tutorial Guide)

but, i'm not sure that this view are true for sub- and trasonic or for incomperesible flow????????????




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Old   June 11, 2013, 06:01
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do anybody have some idea about this?
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Old   June 11, 2013, 10:46
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if i choose the pressure outlet boundary condition, it ask me the pressure and back flow temperature, but i have no data about them.
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Regards,
New to ICEM CFD, try this document --> http://goo.gl/G2gkE
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Old   June 12, 2013, 01:32
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Hi Ali.

please explain more, what i do about temperature?
i try to set some value for these parameters, but, each value has lead to different result!!!!!

Thank you Ali for your attantion
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Old   June 12, 2013, 02:45
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As far as I understand you have a definite outlet e.g. a Boundary where no backflow occures. Hence you can set a Value that makes some sense, like 640C in your case.

This should be ok since you don't assume to have a mass flow over the outlet into your domain in the final state.


Greetz
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