Learning Forum

[Shuvam Paul]

I have simulated a hydraulic jump. There is a difference in water and ambient(air)temperature and as such there is heat transfer across the water-air interface. I have used VOF model and Standard K-epsilon model for the simulation. Energy Model is activated. Radiation is not considered. 

Is there any way to determine the total heat transfer rate across the water-air interface bounded between the two sections(vertical lines) as shown in figure below? Also, is there a way to determine heat flux across the same interface or average equivalent thermal conductivity or average heat transfer co-efficient at the interface.? Also I tried to determine heat flux across a point at the interface in CFD post. But it was shown as "Undefined". While the heat flux at any point at solid boundary could be easily determined. Why?

[Rob]

In Fluent the Heat Flux report is only available for meshed surfaces, ie not iso-surfaces etc. That's in part due to nonmeshed surfaces not having facet normals. You may be able to do something with a combination of a isosurfaces, surface transform and temperature data in Excel but it's going to be a little messy. 

[Shuvam Paul]

Thanks for your Reply ROB. 

I wanted to know if I can create an iso-surface with constant water colume fraction of say 0.7 , bounded by section1 and section 2 as shown in the above figure ? It would be of great help if I could do so.

[Rob]

You can. Create the isosurface of volume fraction and then have a look at isoclip.