convergence problem
 

hi.
I have modeled a impingemnet jet for calculating heat transfer rate over a surface and pedestal.
first of all, i run the model in laminar mode without energy activitation.
the flow field generates correctly.
then i activated the viscous and energy mode and heat transfer.*
in another pc i run my problem in turbulent mode and heat tranfer is activated from the beginning of solution.**

in the case * i didnt gain good result for heat transfer.
in the case ** the flow field did not generate after 4500 iteration and alsothe residuals seem to be horizontal and the value of them is very higher than laminar mode..the continuity residual is higher of all.
what is the problem?
the geometry and mesh is the same for two cases.
what is the reason of not generating flow field after 4500 iteration ? why does residuals go horizontal in a high value