Combined forced and free laminar convection in the entrance region of an inclined isothermal tube

Journal Article · Mon Oct 31 23:00:00 EST 1988 · Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States)

DOI:https://doi.org/10.1115/1.3250591· OSTI ID:5465215

Choudhury, D; Patankar, S V ^[1]

---

1. Univ. of Minnesota, Minneapolis (USA)

An analysis is made of the combined forced and free convection for laminar flow in the entrance region of isothermal, inclined tubes. This involves the numerical calculation of the developing flow with significant buoyancy effects. Three independent parameters are introduced: the Prandtl number Pr, a modified Rayleigh number Ra*, and {Omega}, a parameter that measures the relative importance of free and forced convection. The inclination angle does not appear explicitly in the formulation. Numerical results are obtained for Pr = 0.7, 5, and 10, and representative values of Ra* and {Omega}. The axial development of the velocity profiles, temperature field, local pressure gradient, and the Nusselt number are presented. These results reveal that the buoyancy effects have a considerable influence on the fluid flow and heat transfer characteristics of the development flow. A comparison of the numerical results with the available experimental data is also presented.

• OSTI ID: 5465215
• Journal Information: Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States), Journal Name: Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States) Vol. 110:4A; ISSN 0022-1481; ISSN JHTRA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
CALCULATION METHODS
CONVECTION
ENERGY TRANSFER
FLUID FLOW
FORCED CONVECTION
HEAT TRANSFER
INSTABILITY
LAMINAR FLOW
MASS TRANSFER
NATURAL CONVECTION
NUSSELT NUMBER
ORIENTATION
PRANDTL NUMBER
PRESSURE GRADIENTS
RAYLEIGH-TAYLOR INSTABILITY
TEMPERATURE GRADIENTS
TUBES
VELOCITY