Development of convective heat transfer near suddenly heated, vertically aligned horizontal wires

Journal Article · Sun Nov 01 04:00:00 EST 1987 · Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States)

DOI:https://doi.org/10.1115/1.3248203· OSTI ID:5403432

Parsons, Jr, J R; Arey, Jr, M L ^[1]

---

1. Univ. of Tennessee, Knoxville (USA)

Experiments have been performed which describe the transient development of natural convective flow from both a single and two vertically aligned horizontal cylindrical heat sources. The temperature of the wire heat sources was monitored with a resistance bridge arrangement while the development of the flow field was observed optically with a Mach-Zehnder interferometer. Results for the single wire show that after an initial regime where the wire temperature follows pure conductive response to a motionless fluid, two types of fluid motion will begin. The first is characterized as a local buoyancy, wherein the heated fluid adjacent to the wire begins to rise. The second is the onset of global convective motion, this being governed by the thermal stability of the fluid layer immediately above the cylinder. The interaction of these two motions is dependent on the heating rate and relative heat capacities of the cylinder and fluid, and governs whether the temperature response will exceed the steady value during the transient (overshoot). The two heat source experiments show that the merging of the two developing temperature fields is hydrodynamically stabilizing and thermally insulating. For small spacing-to-diameter ratios, the development of convective motion is delayed and the heat transfer coefficients degraded by the proximity of another heat source. For larger spacings, the transient behavior approaches that of single isolated cylinder.

• OSTI ID: 5403432
• 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. 109:4; ISSN 0022-1481; ISSN JHTRA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
CONVECTION
CYLINDERS
ELECTRIC HEATING
ENERGY STORAGE
ENERGY TRANSFER
HEAT EXCHANGERS
HEAT STORAGE
HEAT TRANSFER
HEATING
INTERFEROMETERS
MASS TRANSFER
MEASURING INSTRUMENTS
MEASURING METHODS
ORIENTATION
RESISTANCE HEATING
STABILITY
STORAGE
TEMPERATURE MEASUREMENT
WIRES