I see no one wants to help me with my programming issue :P.

Maybe u can help with this.

If u got square plate, three isothermal side.

The other side has fluid at some temperature interacting with that side.

Q(rate) = h(transfer coeff)*A*(delta T)

If u take the average temp along that side.

delta T = T(av) - Tf

Yeh??

My question is what area do u use.. since it interacts along a boundary?

Would it just be that length?

Cheers.