Basic concepts-thermal considerations 2.Newton's law of cooling qs=h(T,-Tm力 Not constant! Here,the mean T plays the same role as the free stream T for external flows. 3.Fully developed conditions because of heat transfer,T(r)is continuously changing with x. can fully developed conditions be reached?? For thermally fully developed a T,(x)-T(r,x) =0 x T(x)-T (x) Although the temperature profile T(r)changes with x,the relative shape of the profile no longer changes. Heat Transfer #5 Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 5 Basic concepts—thermal considerations • 2. Newton’s law of cooling • Here, the mean T plays the same role as the free stream for external flows. • 3. Fully developed conditions because of heat transfer, T(r) is continuously changing with x. can fully developed conditions be reached?? • For thermally fully developed • Although the temperature profile T(r) changes with x, the relative shape of the profile no longer changes. ( ) qs  h Ts Tm  T Not constant! 0 ( ) ( ) ( ) ( , ) ,            m fd t s s T x T x T x T r x x