Reply To: Heat transfer at inlets

[Mark Owens]

Hi, There will be diffusion anywhere there is a temperature gradient.  The same applies to species transport with the diffusion determined by the species gradient.

We allow you to  turn it off for inlets because for low velocity inlets the diffusion can be greater than the advection and so you get more heat in than you really want.  Turning it off gives you more control over what is coming in. It would be unphysical to turn it off for an outlet. Nevertheless, for very low velocity inlets where the heat in (or species in) is critical, it is recommended not to use an inlet but a volumetric source.