Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-10T07:19:06.791Z Has data issue: false hasContentIssue false

On the transition to turbulent convection. Part 2. The transition to time-dependent flow

Published online by Cambridge University Press:  29 March 2006

Ruby Krishnamurti
Affiliation:
Geophysical Fluid Dynamics Institute, Florida State University

Abstract

The Rayleigh number at which steady convective flow changes to time-dependent flow is determined experimentally for several fluids with Prandtl numbers from 1 to 104. The time dependence is of two forms: (i) a slow tilting of the cell boundary, with time scale of the vertical thermal diffusion time, (ii) an oscillation with a faster time scale determined by the orbit time of the fluid around the cell. The nature of this oscillation is one of hot (or cold) spots advected with the original cellular motion. At a fixed point in the fluid this produces a time periodic oscillation of the temperature. A discrete change of slope of the heat flux curve accompanies this transition. As the Rayleigh number is increased, transition to disorder is seen to result from an increase in the frequency and number of these oscillations.

Type
Research Article
Copyright
© 1970 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Howard, L. N. 1966 Proceedings of the Eleventh International Congress on Applied Mechanics, 11091115.Berlin: Springer.
Keller, J. B. 1966 J. Fluid Mech. 26, 599606.
Krishnamurti, R. 1970 J. Fluid Mech. 42, 29.
Malkus, W. V. R. 1954a Proc. Roy. Soc. A 225, 185195.
Malkus, W. V. R. 1954b Proc. Roy Soc. A 225, 196–212.
Rossby, H. T. 1966 Dissertation, M.I.T.
Silveston, P. L. 1958 Forch. Ing. Wes. 24, 29–32, 59–69.
Welander, P. 1967 J. Fluid Mech. 29, 1730.
Willis, G. E. & Deardorff, J. W. 1967 Phys. Fluids, 10, 931937.