Internal gravity wave resonance of thermal convection fields in rectangular cavities with heat-flux vibration (effects of aspect ratio on the fields)

Autor: Hideshi Ishida, Shota Matsumura, Kazunari Momose, Genta Kawahara
Rok vydání: 2007
Předmět:
Zdroj: Heat Transfer—Asian Research. 36:158-171
ISSN: 1523-1496
1099-2871
DOI: 10.1002/htj.20149
Popis: In this paper the thermal convection field and its resonance phenomena in a rectangular cavity with heat-flux vibration are numerically examined and the results are compared with those of a square cavity. As in the case of α=1, the critical angular velocity at which the relative amplitude of the midplane Nusselt number αm has a local maximum agrees very well with the resonance angular velocity of the internal gravity wave ωr, estimated by the theoretical equation proposed by Thorpe, even when the aspect ratio is α=5 and the Prandtl number is Pr=0.71 for a range of the Rayleigh number Ra. However, αm has two local maxima for a larger Ra, which is peculiar to the case of larger α. The time variation of sub-components of the fluctuating component of the midplane Nusselt number shows that the phase at the maximum value of αm agrees well with that of the sub-component of velocity for the first resonance angular velocity ωr. For the other angular velocity ωr2, the phase of αm agrees with that of the sub-component of temperature. Moreover, we found that the boundary angular velocity ω0 between the first two of the five ω regions, which classify the thermal convection fields against ω, can be expressed by a function of α, Ra, and Pr and that αm is independent of α and Ra for a relatively wide range of ω/ω0. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(3): 158– 171, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20149
Databáze: OpenAIRE
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