Convection correlations: laminar flow in circular tubes 2. The entry region(contd) for the combined entry length ReD pr/3 0.14 Nun=1.86 LID For values of Rep pr/(L/D)](m/y≥2 T=C 0.48<Pr<16.700 00044<(c/,)<975 Allfluid propertiesevaluated at the mean T +T,)2 m, 7 1,O Heat Transfer Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 6 Convection correlations: laminar flow in circular tubes • 2. The entry region(cont’d) for the combined entry length • For values of 1/3 0.14 / Re Pr 1.86               = s D D L D Nu   Re Pr/( / ) ( / )  2 1/3 0.14 D L D  s  All fluid properties evaluated at the mean T Tm = (Tm,i +Tm,o )/ 2 Ts = C 0.48  Pr 16,700 0.0044  ( / s ) 9.75