Basic concepts-thermal considerations o In the thermally fully developed flow of a fluid with constant properties,the local convection coefficient is a constant,independent of x. h≠f(x) For the special case of uniform surface heat flux ot Axial T dT Independent of gradient Ox fd,t dx fd.t radial location q"cons tant For the case of constant surface temperature Depends on the ot (Ts -T)dTmn radial coordinate 8x\fd. (Ts-Tm)dx T,cons tant Heat Transfer #6 Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 6 Basic concepts—thermal considerations • In the thermally fully developed flow of a fluid with constant properties, the local convection coefficient is a constant, independent of x. • For the special case of uniform surface heat flux • For the case of constant surface temperature h  f (x) fd t m fd t dx dT x T , ,    q cons t s   tan Axial T gradient Independent of radial location fd t m s m s fd t dx dT T T T T x T , , ( ) ( )      T cons t s  tan Depends on the radial coordinate