Numerical simulation of three-dimensional mixed convection heat transfer from an array of discrete heat sources in a horizontal rectangular duct

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Numerical Heat Transfer (Washington, D.C.); (USA)

DOI:https://doi.org/10.1080/10407788908944717· OSTI ID:5171736

Mahaney, H V; Ramadhyani, S; Incropera, F P ^[1]

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1. Purdue Univ., Lafayette, IN (USA). School of Mechanical Engineering

Using a vectorized finite-difference marching technique, the steady-state continuity, momentum, and energy equations are solved numerically to evaluate the effects of buoyancy-induced secondary flow on forced flow in a horizontal rectangular duct with a four-row array of 12 heat sources flush mounted to the bottom wall. Secondary flows, in the form of longitudinal vortices, initially develop at spanwise positions corresponding to the edges of the heat sources. Additional plumes and vortices subsequently develop across the heater width, leading to the eventual formation of large-scale circulation patterns. For a fixed Rayleigh number and decreasing Reynolds number, the row-average Nusselt numbers decrease, reach a minimum, and subsequently increase due to bouyancy effects. Thus, due to buoyancy-induced secondary flow, conditions exist for which heat transfer may be enhanced by reducing the flow rate and hence the pump ower requiement. Heat transfer enhancement above the forced convection limit, as well as the Reynolds number range for which enhancement occurs, increases with increasing Raleigh number. Appropriate scaling parameters are introduced to characterize the strength of the buoyancy-induced secondary flow and to delineate conditions for which it is significant.

• OSTI ID: 5171736
• Journal Information: Numerical Heat Transfer (Washington, D.C.); (USA), Journal Name: Numerical Heat Transfer (Washington, D.C.); (USA) Vol. 16:3; ISSN 0149-5720; ISSN NUHTD
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
CONVECTION
DUCTS
ENERGY TRANSFER
EQUATIONS
FINITE DIFFERENCE METHOD
FORCED CONVECTION
HEAT TRANSFER
HEATERS
ITERATIVE METHODS
MASS TRANSFER
NUMERICAL SOLUTION
NUSSELT NUMBER
PARAMETRIC ANALYSIS
REYNOLDS NUMBER
SCALING
THREE-DIMENSIONAL CALCULATIONS