Reply To: Unstable total heat transfer rate and total mass flow rate

[w.u.maddumage]

Hi Rob,

I started a transient from the last steady state results of the 6M cell mesh. With adaptive time stepping, I ran around 4000 time steps, total flow time of the simulation = 0.04s. 

The total heat transfer rate graph is stable in the transient solution. But it shows a high error. The user energy source here is 2.6W. As you can see the graph deviates a lot from -2.6 W. 

I should note that the convergence of the solution is much better with the transient. With the steady state, I was not able to bring continuity residuals below 1e-3. But with the transient, every step reaches convergence within 2 to 5 iterations. 

Please let me know if you need more data on the transient results.