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Channel flow induced by a travelling thermal wave

Published online by Cambridge University Press:  29 March 2006

Chuen-Yen Chow
Affiliation:
Department of Aerospace Engineering Sciences University of Colorado, Boulder, Colorado

Abstract

Experiments conducted elsewhere show that a mean fluid motion can be induced in a channel by a travelling thermal wave. An analysis is carried out, linearized under the assumption that the induced motion is slower than the speed of the heat source. The expression for the mean motion is obtained for any Prandtl number and circular frequency of the thermal wave, to complete the results presented by Davey (1967) for low and high frequency ranges.

In the problem of the flow between two parallel plates, it is found that with a temperature profile symmetric about the centre of the channel, the induced flow does not exert a net shear force on either plate, while with a non-symmetric one, the plates are subjected to equal and opposite forces.

For the problem that the upper surface of the fluid is free and thermally insulated, an approximated result can be deduced from that of the previous problem by a simple transformation. It should agree with the result of Davey, obtained through a more elaborate procedure, except in the low frequency range when the surface deformation becomes important.

In agreement with the experiments, our analysis indicates that the induced mean motion is always in a direction opposite to that of the thermal wave, and its magnitude increases rapidly with decreasing Prandtl number. According to the theory, some of the previous experiments were not conducted under the optimum situations, and improved experimental conditions are suggested.

Type
Research Article
Copyright
© 1970 Cambridge University Press

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References

Davey, A. 1967 The motion of a fluid due to a moving source of heat at the boundary. J. Fluid Mech. 29, 137.Google Scholar
Fultz, D., Long, R. R., Owens, G. V., Bohan, W., Kaylor, R. & Weil, J. 1959 Studies of thermal convection in a rotating cylinder with some implications for large-scale atmospheric motions. Meterol. Monogr. 4, no. 21, 36.Google Scholar
Landau, L. D. & Lefshitz, E. M. 1959 Fluid Mechanics. London: Pergamon.
Schubert, G. & Whitehead, J. A. 1969 Moving flame experiment with liquid mercury: possible implications for the Venus atmosphere. Science, 163, 71.Google Scholar
Schubert, G. 1969 High velocities induced in a fluid by a travelling thermal source. J. Atm. Sci. 26, 767.Google Scholar
Smith, B. A. 1967 Rotation of Venus: continuing contradictions. Science, 158, 114.Google Scholar
Stern, M. E. 1959 The moving flame experiment. Tellus, 11, 175.Google Scholar