[Astropower]

Hello All;
I'm new to this forum.
I'm using Star-CCM to simulate a tube having a hot spot in the middle of it. water flow inside this tube as a coolant.
I'm asking about the stopping criteria.
Residuals seem to saturate after about 300 iterations, and I can achieve temperatures of hot water and the hot spot on the tube.
When I increase to iterations (with very saturated residuals still) to say 5000, temperature of the hot spot on the tube seem to increase noticeably.

So, how to judge the adequacy of the number of iterations, and which one is correct : the results with few (300) iterations or that with 5000 iterations

Thanks