Heat transfer problem in flow simulation

I got it, was a stupid fault, the inlet velocity of the water was way too high for the heat to be effectively transferred (it was only heating up by about .5 C).

Now it's working much better.

Ya you are right....it may either bcoz of inlet value or the non conformal meshes that may occur on the model if we are not meshing it properly..

When ever solving a flow problem may be thermal flow or internal flow think once or twice for choosing a crt boundary conditions...

And for thermal energy equation is mandatory...

Then choose a proper viscous model for your problem ...

If curve is diverging during iteration adjust the correntnumber ....

If still it is diverging the redefine the mesh and do the process again...

Enable plot while iteration that will be easy