Internal convection heat transfer coefficient (summary) 1. For laminar and fully developed flow(88.4.1) 1. q constant: N lD=436 Eq.8.53 ii. s constant N 3.36 Eq.8.55 2. For laminar flow in entry region(before fully developed flow,88.4.2 D i. Ts constant 0.0668二 Ren pr Ni 3.66+ 2/3 Eq.8.56 1+0.04 Ren pr Combined entry length with full tube 0.14 Re P N 186 D LID Eq.8.57 3. For turbulent and fully developed (s8.5) Heating Nu=0.023 Re 45 Pr0.4 ii. Cooling Nu=0.023 Re 4/5 Pr 3q.8.60 Allfluidproperties evaluated at the mean t +T) 2 m, 7 2,O Heat Transfer Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 8 Internal convection heat transfer coefficient (summary) 1. For laminar and fully developed flow (§8.4.1): i. q” constant: ii. Ts constant: 2. For laminar flow in entry region (before fully developed flow, §8.4.2: i. Ts constant : ii. Combined entry length with full tube: 3. For turbulent and fully developed (§8.5) i. Heating ii. Cooling 2/3 Re Pr L D 1 0.04 Re Pr L D 0.0668 3.66             +       = + D D NuD 1/3 0.14 / Re Pr 1.86               = s D D L D Nu   All fluid properties evaluated at the mean T Tm = (Tm,i +Tm,o )/ 2 Eq. 8.53 Eq. 8.55 Eq. 8.56 Eq. 8.57 Eq. 8.60 4/5 0.4 0.023Re Pr NuD = D 4/5 0.3 0.023Re Pr NuD = D NuD = 4.36 NuD = 3.36