IR LED solidworks thermal simulation unexpected extreme low temperature problem

[seraph3333]

Hi,
In solidworks thermal simulation, I built up this following model:
Have 70 piece of IR LED arranged on a round 8-inch PCB, each LED is 11W.
Set the LED emissivity as 0.9, the material to be heater emissivity as 0.6
All body initial temperature as room temperature.
All face convection as 50W/m2.K
The thing is after steady state study, the thermal result shows extreme low temperature, such as -850C.

Not sure where did I set wrong, please help.

Thanks,
Hao

 

[FEA way]

Such problems are often caused by too coarse mesh, try refining it significantly. Also, make sure that the initial temperature is properly applied to the whole model.

 

[seraph3333]

Thank, FEA way.
But mesh are very fine down to 1mm.
And the initial temperature is applied to all bodies.
Any other place could I did wrong?