Learning Forum

[Biborka Boga]

Hi. I am working on the simulation of liquid film flow in an inclined channel (35 degree compared to the horizontal position). I am modeling only a reduced segment of the channel (1.32 mm) using the mixture multiphase model.

The problem is that even along the modelled channel length, an uenxpected thinning of the liquid film has been observed (please find below).

 

Can you please offer me some hints why this considerable thinning of the liquid film can be observed?

Thank you very much in advance your response!

 

[SRP]

Hi,

Did you specify both the component of gravity based on the inclination?

Can you please share boundary condition, multiphase setting, and turbulence models use?

Thank you

Saurabh

 

[Biborka Boga]

First, thank you very much your feedback.:)

Please find below the specifications:

• laminar (viscous settings)
• I have defined g considering the inclination (i.e., angle) of the channel relative to the horizontal position, namely g for X: g*sin(angle) and for Y=-g*cos(alfa)
• Mixture mutiphase model

Regarding to the BC at the inlet I have had velocity inlet, and at the otlet pressure outlet. I have defined a symmetry BC, and wall BC (for the upper wall, sidewall, and bottom).

Thank you very much in advance your hints.

Although a certain thinning was expected, but not as much (as in the current simulation).

[Rob]

It's because it's a liquid so is flowing (accelerating) downwards.  With VOF there's an open channel boundary which avoids this issue, but that'll cause problems with the phase change model(s). 

[Biborka Boga]

Thank you very much your response! :) I totally agree with you regarding to the open channel BC (VOF), since I have applied it as a first approach.

I will try to find a solution. Thank you again for all!