[Albert Lee]

Hi everyone!
I have used the VOF method to simulate the mass transfer from a liquid phase to vapor phase in a storage tank. The gravity level is zero.
[problem description] I have use udf files to load my mass transfer mechanism on Fluent, the mass transfer mechanism is Lee model as Fluent help files described. In my udf, I limited the mass transfer position to the interface. The capturing of interface with VOF method is good. The boundary condition is shown in the first figure. And the temperature distribution is show in the second figure.

physical model.pngtemperature distribution.png

Now I have some questions looking forward to your answers :
After I simulated for 8s, the temperature distribution is obviously unphysical. the temperature of the vapor phase (ullage) should be lower than that of liquid phase, and the temperature should distributed with
thermal stratification from the heat source to vapor phase, but the result is just the contrary! I really don't know how to solve it! The properities of fluids was set as the Fluent database given.
By the way, the mass transfer occured normally according my define in the udf flie. The vapor phase was set as ideal gas.

Is there some methods to solve the problem I confronted above? Thank you!

[vidyadhar]

Hello Albert Lee, I am also facing this problem. I am not sure if it may be rectified by using DEFINE_MASS_TRANSFER instead of DEFINE_SOURCE ?



Regards,
vidyadhar