Learning Forum

[mtobaben]

Hello everybody,

I am currently simulating a droplet flow inside a vessel.

As you can see in the picture attached, the droplets of the disperse phase rise up in the continuous phase due to

a density difference. The droplets are introduced into the vessel with a temperature of 286K, while the temperature

of the continuous phase is 296K. During the ascent there is a heat transfer between both phases.

I used a 2-dimensional, planar model and the VOF-method to do the simulation.

Now my question is the following: is there a possibility to determine the heat transfer or the heat transfer coefficient

between the phases?

Thank you a lot and best regards,

Max

[Rob]

You'll need to calculate/report the temperature on the bubbles & surface area and then back calculate the HTC. There isn't a geometric entity to do flux reporting on. I'd also suggest reading the background theory on the VOF model in the manuals. 

[mtobaben]

Hello,
I already read the manual in detail, but sometimes it is very hard to comprehend, what Ansys is calculating in the background.
The biggest issue is, that usually you use the heat tranfer coefficient combined with a surface area, which we do not have in
2-dimensional model.
I would be very grateful, if you could elaborate your approach.
Thanks a lot!

[Rob]

But we don't use a HTC to transfer energy, we use the gradients, properties etc.  HTC is a derived value that's used to allow a comparison of designs.