convergence in transient runs
 

Hi, I've got a question concerning the convergence of the engergy equation in an single load step transient computation: ENTH is about 5e+02. I am calculating natural convection with 3.22. I use MARS for the temperature and decided to "bound" the solver by setting 0.01 and 1000 internal sweeps for temperature. Can anybody help me to converge the computation?