“…The thermal boundary condition at the outlet are not known explicitly. At the outlet or at the downstream infinity �𝜕𝜕 * 𝛽 𝛽�, the fluid temperature gradient in regard to the axial coordinate will tend to vanish, that is �𝜕𝜕𝜕𝜕 � /𝜕𝜕𝜕𝜕 * � 0� [26], [23], [36], [37] and the temperature at the outlet is a particular solution of the energy equation Eq. ( 7) as - 129 -…”