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CEL expression for calculating center of gravity (multi-phase flow)

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Old   October 4, 2016, 08:54
Default CEL expression for calculating center of gravity (multi-phase flow)
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Qiong-yao Wang
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Hello, everyone, I am now doing liquid sloshing in a closer tank with CFX. Multi-phase flow (air phase and water phase) is considered in my case. I want to obtain the time-history of the center of the gravity of liquid (water) during sloshing, using CEL expression. however, I don't know how to write the CEL expression. Could anyone help me? Thanks a lot.
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Old   October 4, 2016, 11:49
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Before you attempt to write the CEL expression, you must have the formulas of what you are trying to compute.

In the case of the center of gravity, what do you think the formulas should be ? You can express them in mathematical terms, or plain English.

Several here in the forum will be able help you to translate your formulas into CEL
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Old   October 12, 2016, 06:56
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Quote:
Originally Posted by Opaque View Post
Before you attempt to write the CEL expression, you must have the formulas of what you are trying to compute.

In the case of the center of gravity, what do you think the formulas should be ? You can express them in mathematical terms, or plain English.

Several here in the forum will be able help you to translate your formulas into CEL
Hello, Opaque.
Thanks for your replying. I attached the formulation, please check that.
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Old   October 12, 2016, 18:17
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You can get total liquid volume from volumeInt(liquid.volume fraction)@domain.

The sum over the mesh with a volume weighting is volumeInt(x*liquid.volume fraction)@domain

I will leave it up to you from there
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Old   October 14, 2016, 02:53
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Quote:
Originally Posted by ghorrocks View Post
You can get total liquid volume from volumeInt(liquid.volume fraction)@domain.

The sum over the mesh with a volume weighting is volumeInt(x*liquid.volume fraction)@domain

I will leave it up to you from there
Hi, ghorrocks.
Thanks for your help. Well, volumeInt(liquid.volume fraction)@domain can be used to calculate the total liquid volume, while, this is something wrong with volumeInt(x*liquid.volume fraction)@domain. Since, in the fist, 'x' is a disallowed argument, so I used 'xGlobal' to substitute it. In the second, CFX give me a hint that only arguments that consist of a single recognised variable name are supported by the solver. In your expression, there are two variable names, which are 'x' and 'liquid.volume fraction' , respectively. So please help me to how to figure it out. Thanks a lot.
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Old   October 15, 2016, 18:50
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Define a variable of q = x*liquid.volume fraction. Then volumeInt(q)@domain should work.
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Old   March 29, 2020, 08:55
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Dear hellowqy
Did you solve this problem? if yes, can you please share the details? I need it desperately.
Can anyone else help?
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