[DomBadger]

Hello, I simulated a turbulent diffusion flame and now trying to calculate the incident thermal radiation to several remote radiometers (targets) around the flame at various distances. The radiometers have a hemisphere view, which means they have a facing direction and are only receiving thermal radiation coming towards them.

But the "incident radiation" variable in Fluent seems not the right one to use here. When I created a bounded surface/plane by giving the coordinates of 3 points, and used the variable "Integral--radiation--incident radiation" to get the incident thermal radiation on the surface, the values were clearly off.

What's more, I found that the bounded surface created indeed has a normal direction, because the mass flow rate through it would adopt opposite signs if I switch the order of the 3 points used to create the surface (either clockwise or counterclockwise). However, even surfaces with the opposite normal direction would lead to the exact same value of "Integral--radiation--incident radiation".

Already read this thread Measuring Radiaiton from a Flame but the question is not solved.

I wonder how to create a surface only facing one side and is a wall on its back. Or any of your experience in obtaining a reasonable incident thermal radiation value.