Mixed-convection heat transfer in an open shallow cavity heated from below and packed with a one-step arrangement of spherical particles

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Heat Transfer - Japanese Research; (United States)

OSTI ID:6833343

Inaba, Hideo; Ozaki, Koichi; Nozu, Shigeru ^[1]

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1. Okayama Univ. (Japan). Faculty of Engineering

Heat-transfer measurements were performed during forced and natural mixed convection of a rectangular open cavity which was packed with spherical particles arranged in a one-step orthorhombic array. Air flowing over the cavity was heated from the bottom surface of the cavity via the particle layer. Three kinds of spherical particles having almost the same diameter of 10 mm and different thermal conductivities were used as the spherical packing material. The cavity depth was varied from 0 mm (flat plate) to 10 mm. The particles suppressed the air motion near the heating surface and decreased the heat-transfer coefficient. In the case of particles having a large thermal conductivity, the particles behaved as an extended heat-transfer surface and turbulence promoter so that the heat-transfer coefficient was enhanced. The Nusselt number ratio as a dimensionless heat-transfer coefficient was expressed in terms of Reynolds number, ratio of particle diameter to depth of the cavity, and a modified Prandtl number.

• OSTI ID: 6833343
• Journal Information: Heat Transfer - Japanese Research; (United States), Journal Name: Heat Transfer - Japanese Research; (United States) Vol. 23:1; ISSN 0096-0802; ISSN HTJPAU
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
CAVITIES
CONVECTION
ENERGY TRANSFER
FLUID FLOW
GAS FLOW
HEAT TRANSFER
MASS TRANSFER
MATERIALS
PHYSICAL PROPERTIES
POROUS MATERIALS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES