Laminar natural convection in a horizontal rhombic annulus

Journal Article · · Numerical Heat Transfer. Part A, Applications; (United States)

DOI:https://doi.org/10.1080/10407789308902604· OSTI ID:6025790

Moukalled, F; Diab, H ^[1]; Acharya, S ^[2]

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1. American Univ. of Beirut (Lebanon)
2. Louisiana State Univ., Baton Rouge, LA (United States). Mechanical Engineering Dept.

This paper presents the simulation of heat transfer and flow patterns in an enclosure between two isothermal concentric cylinders of rhombic cross sections. Four different values of the enclosure gap (E[sub g] = 0.875, 0.75, 0.5, and 0.25) and three different rhombic angles ([Omega] = 10[degree], 20[degree], and 30[degree]) are considered. At low Rayleigh numbers (10[sup 3]--10[sup 5]) the flow is weak and conduction is the dominant mode of heat transfer. Convection plays a key role starting at higher Rayleigh numbers (10[sup 6]--10[sup 7]). For all cases studied, there is no tendency for flow separation at the horizontal corners. The flow strength is found to increase with increasing rhombic angle, increasing enclosure gap, and increasing Rayleigh number.The critical Rayleigh number at which the heat transfer is influenced by convection decreases with increasing gap values and increasing rhombic angle; it is as high as 10[sup 6]--10[sup 7] for E[sub g] = 0.25 and decreases to about 10[sup 4] for E[sub g] = 0.875.

• OSTI ID: 6025790
• Journal Information: Numerical Heat Transfer. Part A, Applications; (United States), Journal Name: Numerical Heat Transfer. Part A, Applications; (United States) Vol. 24:1; ISSN NHAAES; ISSN 1040-7782
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
ANNULAR SPACE
CALCULATION METHODS
CONFIGURATION
CONVECTION
CYLINDERS
ENERGY TRANSFER
FINITE DIFFERENCE METHOD
FLUID FLOW
HEAT TRANSFER
ITERATIVE METHODS
LAMINAR FLOW
MASS TRANSFER
NATURAL CONVECTION
NUMERICAL SOLUTION
ORIENTATION
SPACE