Internal gravity wave resonance of thermal convection fields in rectangular cavities with heat-flux vibration (effects of aspect ratio on the fields)
✍ Scribed by Shota Matsumura; Hideshi Ishida; Kazunari Momose; Genta Kawahara
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 287 KB
- Volume
- 36
- Category
- Article
- ISSN
- 1099-2871
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✦ Synopsis
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 α m has a local maximum agrees very well with the resonance angular velocity of the internal gravity wave ω r , 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, α m 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 α m agrees well with that of the sub-component of velocity for the first resonance angular velocity ω r . For the other angular velocity ω r2 , the phase of α m agrees with that of the sub-component of temperature. Moreover, we found that the boundary angular velocity ω 0 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 α m is independent of α and Ra for a relatively wide range of ω/ω 0 .