Radiaition modelling

Hi All,

Im very new to LB models and have been trying to solve radiation equations recently using LB. I am little confused on how should I implement a thermal boundary conditions for boundaries at Temperatures T1 and T2. I am solving the LB for Radiaiton Intensity, I. This is what I have been coding till now, but the code is not working properly.

at x =0; T= T1 ==> f1(1)=(I1)-f2(1) ; where I1=(epsilonsigmaT1^4)/pi

at x = L; T = T2 ==> f2(L)=(I2)-f1(L) ; where I2 = (epsilon * sigma * T2^4)/pi

I would greatly appreciate any help in this regard as i am struggling for quite a long time now.