Convective Heat transfer Coefficient h= T、-T y=0 h= Empirical or Nusselt c N- Semi-empirical Number0 0 ( ) ( ) = − − ∞ ∂ = ∂  − = − − ⋅ = ∞ y LyT T T T cf s y y T f cs s dd Lk T T k h Nu Nusselt Number f u c k N h L = Empirical or Semi-empirical Convective Heat transfer Coefficient