Solution divergence when energy equation is enable
 

Hi all,

I'm a new Fluent user. I'm running a reacting flow simulation with reactions disabled (cold flow). I started the simulation by solving the flow, species equations, k & epsilon. After the solution is stable; about 30000 + iterations, I turn on the energy equation. In about 100 iteration, the solution became divergence. I do a lot of trial & error by adjusting the under relaxation factor, but, it's not working..what should I do??:confused:

Please help me....thanks.