Simcenter STAR-CCM+ How do I quantify the amount of mass in a fluid film?

If you have activated the fluid film model, you may want to know not just the thickness of the fluid film over time, but also the total amount of mass accumulated in the fluid film over time. This is often referred to as "Wall-Wetting."| 

I will describe two ways to evaluate the film mass over time:

• Summation Approach: 
  • Create a new User-defined field Function namely "Wall-Wetting"
  • Definition: $FluidFilmThickness*$Density*mag($$Area) 
  • Dimensions: Mass: 1 for the field function
  • Sum Report: "Wall-Wetting" field function on the Shell Interface
• Surface Integral Approach:
  • Create a new User-defined field Function namely "FilmMass"
  • Definition: $FluidFilmThickness*$Density
  • Dimensions: Mass: 1, Length: -2 for the field function
  • Surface Integral: "FilmMass" field function on the Shell Interface

To determine "wall-wetting", you can create a field function to determine the amount of mass in the fluid film in each cell. 



This field function can then be viewed in a scalar scene to see the mass accumulated locally in the fluid film over time. It can also be used in a summation report to determine the total accumulated mass in the fluid film over time. 


As seen in the above plots both approaches should result in identicaly results, it is only a choice of preference for the user.