[andbe]

Dear CFD Online Forum,

I want to modell a serpentine heat exchanger in Ansys. Air will flow inside the pipe extracting heat from the surrounding grund.

The problem is that the pipe is over 400m long (going back and forth with lots of elbow turns) and it has a very small diameter (about 25mm) and wall thickness. The size of the problem is therefore too large to be modelled.

My plan is now to modell it using one of Fluents "Heat Exchanger Models". The problem is that you have to specify an auxiliary fluid with inlet temperature and velocity. Since I only have the solid ground around the serpentine pipe my question is; does anyone know if/how I could manage to describe my heat exchanger using this model? Do anyone have any other suggestions solving/simplifying this problem?

Any help would be very appriciated!