residuals
 

I have a pipe with heat flux outside and I select for the picture 2 K-epsilon turbulence and the picture 1 Reynolds Stress Turbulence. wath do you think about the Residuals? are it good? or I nedd more iteration? when will I get the best solution? I am new with cfd.

Nusselt Number
 

I have a pipe with heat flux outside, I have a line of point inside the pipe with a fluid, I should have the temperature the pressure and de Nusselt Number, but for temperature and pressure I have normal result but in the case of Nusselt Number my values are always 0. anyone know what is happening? we can see the pictures.

To make sure which model ( k-epsilon or reynolds ) is proper, you need to evaluate by
1- a real case that exist and you can check some values, such as velocity and compare with the simulation.
2- or check some specific numbers such as drag coefficient in some place of the flow.
What is the reason that the continuity is not converged in the simulation?

I can check with the outlet and inlet of the temperature and pressure, or calculate the velocity.

with both I have good result of the pressure (inlet and outlet) but with both outlet temperarure changes 10 ºC-20 ºC which depends the model.

I do not have idea why the continuity is not converged in the simulation?

could you tell me something about Nusselt Number?