Forced convection heat transfer in rectangular ducts: general case of wall resistances and peripheral conduction

Conference · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6696693

Lyczkowski, R. W. ^[1]; Solbrig, C. W. ^[2]; Gidaspow, D. ^[3]

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1. Institute of Gas Technology, Chicago, IL (United States)
2. Commonwealth Edison Co., Chicago, IL (United States)
3. Illinois Inst. of Technology, Chicago, IL (United States)

A numerical solution for laminar flow heat transfer between a flowing gas and its containing rectangular duct has been obtained for many different boundary conditions. The problem has been solved for the cases of insulation on no walls, one wall, two walls, and three walls with various finite resistances on the remaining walls. Results have been obtained for several duct aspect ratios in the thermal entrance and in the fully developed regions, including the constant temperature cases. When one wall is insulated and the other three are at constant temperature, the maximum temperature occurs in the fluid rather than on the insulated wall. This maximum moves toward the insulated wall with increasing axial distance. Nusselt numbers for the same constant flux on all four walls with peripheral conduction lie in a narrow band bounded by zero and infinite peripheral conduction cases. A dimensionless wall conduction group of four can be considered infinite for the purpose of estimating fully developed Nusselt numbers to within an accuracy of 3%. A decrease in wall and bulk temperatures by finite wall conduction has been demonstrated for the case of a black body radiation boundary condition.

• OSTI ID: 6696693
• Report Number(s): CONF-801102--33
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
CONVECTION
DATA
DUCTS
EXPERIMENTAL DATA
FLOW RATE
FLUID FLOW
FORCED CONVECTION
GAS FLOW
INFORMATION
LAMINAR FLOW
MATHEMATICAL MODELS
NUMERICAL DATA
NUMERICAL SOLUTION
NUSSELT NUMBER
PHYSICAL PROPERTIES
TEMPERATURE DEPENDENCE
THERMAL CONDUCTIVITY
THERMAL INSULATION
THERMODYNAMIC PROPERTIES