[chberbelali]

Hello Cfds!

I am in the process of programming the local & average Nusselt number in a left vertical wall but my Matlab script gives me inappropriate values and it doesn't change with changing of Rayleigh number .

The expressions of the local nusselt: (-dT/dx)|x=0

My script: using finite difference approximation with 5points- Forward scheme ( j=1 to m+1 and i=1 )

Nu_loc = zeros(1,m+1);
    for j=1:m+1
        Nu_loc(j) = -(-25*T(1,j)+48*T(1+1,j)-36*T(1+2,j)+16*T(1+3,j)-3*T(1+4,j))/(12*hx);   
    end

i'll very grateful for any help