Laminar fully developed mixed convection in inclined tubes uniformly heated on their outer surface

Journal Article · Thu Dec 01 04:00:00 EST 1994 · Numerical Heat Transfer. Part A, Applications; (United States)

DOI:https://doi.org/10.1080/10407789408956019· OSTI ID:6491139

Laouadi, A; Galanis, N ^[1]; Nguyen, C T ^[2]

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1. Univ. of Sherbrooke, Quebec (Canada). Faculte des sciences appliquees
2. Univ. de Moncton, New Brunswick (Canada). Ecole de genie

The problem of conjugate heat transfer involving mixed convection laminar ascending flow of water in inclined circular tubes uniformly heated on their outer surface has been studied numerically using a unified formulation for the solid and fluid domains. The highly coupled governing equations were discretized using the control volume approach, and solved according to the SIMPLER algorithm. Results have clearly demonstrated that the conduction within the tube wall has an important influence on both the hydrodynamic and thermal fields. High wall thermal conductivity or large thickness reduces the temperature stratification within the fluid and intensifies the secondary motion, consisting of two symmetrical vortices. The effects of wall conduction are particularly significant for horizontal tubes for which the average Nusselt number is bounded by two limits corresponding to the case of infinite will thermal conductivity and zero wall thermal conductivity. For Gr = 2 [times] 10[sup 5] these limits are 10.42 and 9.03, respectively. These effects are negligible for tubes inclined at 30[degree] and for Grashof number below 3 [times] 10[sup 4].

• OSTI ID: 6491139
• Journal Information: Numerical Heat Transfer. Part A, Applications; (United States), Journal Name: Numerical Heat Transfer. Part A, Applications; (United States) Vol. 26:6; ISSN 1040-7782; ISSN NHAAES
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
CONVECTION
ENERGY TRANSFER
EQUIPMENT
FLUID FLOW
FORCED CONVECTION
HEAT EXCHANGERS
HEAT TRANSFER
INCOMPRESSIBLE FLOW
MASS TRANSFER
NATURAL CONVECTION
SOLAR COLLECTORS
SOLAR EQUIPMENT
VAPOR CONDENSERS