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Even with different superheat amount of vapor is same

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Old   March 7, 2020, 02:17
Default Even with different superheat amount of vapor is same
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hello,

I am simulating a film boiling phenomenon.

I am using following models:


Multi-phase: VOF
Scheme: Implicit
Turbulence: k-e
Methods: default
Controls: default
Phase change: Lee model (r = 0.1)



My Problem is: Very little difference (almost overlapping in graph) in amount of vapor generation even when degree of super-heat is increased by 45K.



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Old   March 7, 2020, 07:34
Default Pre-existing Vapor
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What's the fraction of vapor at the initialization? The model requires a positive vapor fraction at initial stage.
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Old   March 8, 2020, 00:41
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Quote:
Originally Posted by vinerm View Post
What's the fraction of vapor at the initialization?
At the initialization the fraction of vapor is zero.





Quote:
Originally Posted by vinerm View Post
The model requires a positive vapor fraction at initial stage.
Why so?
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Old   March 8, 2020, 04:29
Default EC model Implementation
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The way the model is implemented, it checks for the minimum value of both phases to determine the mass transfer. If vapor fraction is always zero, the mass transfer will never begin.
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