In my transient CHT analysis, energy balance(IN + OUT heat flux = Absorbed heat flux) for 1 and 2 sec is very high.(total time - 10s, time step - 0.01 and, error threshold 0.01. Default time integration scheme is Implicit). For rest of the time period, error is respectable. I am trying to reduce mesh size and CFL for this. My question is that do i need to do mentioned general solution(reduce time step and mesh size) or reduced convergence limit for energy solver for this to reach the acceptable value for 1 and 2 sec or this usually occurs.  

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