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Fluid flow boundary integration

Posted 14 mars 2011, 06:37 UTC−4 5 Replies

Xsu
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Hi,
for 2-D axis, in order to find the volumetric flow rate, just perform integration across the boundary will generate [m^3/s]
I am now doing with 2-D, integration across the boundary will only generate [m^2/s]. Is there any method to find volumetric flow rate[m^3/s] in 2-D?

Thanks.
5 Replies Last Post 15 mars 2011, 11:18 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 14 mars 2011, 08:17 UTC−4
Hi

in 2D and 2D axi the integration over an edge is in 2D assumed over an area of by default 1[m] depth (slightly physics dependent, always check the main physics node for default depth ("d" or "thickness" values)

in 2D-axi you must multiply by 2*pi*r the "loop length" tis can be done ba COMSOL in Results post processing mode if you go to the advanced tab ana select integrate over volumes for 2D-axi. But you must specify it manually if you use "operator" or integration coupling variables

--
Good luck
Ivar
Hi in 2D and 2D axi the integration over an edge is in 2D assumed over an area of by default 1[m] depth (slightly physics dependent, always check the main physics node for default depth ("d" or "thickness" values) in 2D-axi you must multiply by 2*pi*r the "loop length" tis can be done ba COMSOL in Results post processing mode if you go to the advanced tab ana select integrate over volumes for 2D-axi. But you must specify it manually if you use "operator" or integration coupling variables -- Good luck Ivar
Xsu
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Posted: 1 decade ago 14 mars 2011, 10:13 UTC−4
Thanks Ivar for advice, for 2-D axis, similar integration can be found at tutorial-peristaltic pump. Quite nice the simulation.

However, for my case, I am applying 2-D where integration over the boundary will only create area flow rate [m^2/s].
Is there any possible we can have volume flow rate [m^3/s]?

Thanks and appreciate for advice.
Thanks Ivar for advice, for 2-D axis, similar integration can be found at tutorial-peristaltic pump. Quite nice the simulation. However, for my case, I am applying 2-D where integration over the boundary will only create area flow rate [m^2/s]. Is there any possible we can have volume flow rate [m^3/s]? Thanks and appreciate for advice.
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 15 mars 2011, 04:21 UTC−4
Hi

I believe its so if you multiply by the depth "z" direction, as an edge in 2D is a surface of a given depth (mostly by default 1[m]

--
Good luck
Ivar
Hi I believe its so if you multiply by the depth "z" direction, as an edge in 2D is a surface of a given depth (mostly by default 1[m] -- Good luck Ivar
Xsu
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Posted: 1 decade ago 15 mars 2011, 09:55 UTC−4
Hi Ivar,

I am trying with the Results post processing boundary integration mode but it only shows area flow rate when I select the inlet boundary. and surface integral is only applied to axisymmetric mode. Thus, I think the flow rate only applied to area flow rate in 2-D mode.
Hi Ivar, I am trying with the Results post processing boundary integration mode but it only shows area flow rate when I select the inlet boundary. and surface integral is only applied to axisymmetric mode. Thus, I think the flow rate only applied to area flow rate in 2-D mode.
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 15 mars 2011, 11:18 UTC−4
Hi

I'm somewhat confused now, it's difficult to understand correctly only with words.

Have you tried to make a simple example, that you can easily check by a simple analytical formula, then you ususlly arrive to better understand the relationship required, or missing

--
Good luck
Ivar
Hi I'm somewhat confused now, it's difficult to understand correctly only with words. Have you tried to make a simple example, that you can easily check by a simple analytical formula, then you ususlly arrive to better understand the relationship required, or missing -- Good luck Ivar

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