unsmooth heat flux distribution along the wall, why?
 

I am trying to evaluate the heat flux distribution along a iso-temperature wall, but the distribution is kind of unsmooth(that can be seen in attached figure,especially in the area marked by black circle), like fluctuating near a baseline. Other parameters such as pressure distribution is quite normal and smooth.
How that happened? Many thanks!
SST k-omiga turbulent model is used in my simulation.