 
Summary: J. Fluid Mech. (2005), vol. 523, pp. 251260. c 2005 Cambridge University Press
DOI: 10.1017/S0022112004002289 Printed in the United Kingdom
251
Heat transport by turbulent RayleighB´enard
convection in cylindrical cells with aspect
ratio one and less
By ALEXEI NIKOLAENKO, ERIC BROWN,
DENIS FUNFSCHILLING AND GUENTER AHLERS
Department of Physics and iQUEST, University of California, Santa Barbara, CA 93106, USA
(Received 4 September 2004 and in revised form 8 October 2004)
We present highprecision measurements of the Nusselt number N as a function of
the Rayleigh number R for cylindrical samples of water (Prandtl number = 4.4)
with a diameter D of 49.7 cm and heights L = 116.3, 74.6, and 50.6 cm, as well as for
D = 24.8 cm and L = 90.2 cm. For each aspect ratio D/L = 0.28, 0.43, 0.67, and
0.98 the data cover a range of a little over a decade of R. The maximum R 1012
and Nusselt number N 600 were reached for = 0.43 and D = 49.7. The data were
corrected for the influence of the finite conductivity of the top and bottom plates
on the heat transport in the fluid to obtain estimates of N for plates with infinite
conductivity. The results for N and > 0.43 are nearly independent of . For
= 0.275 N falls about 2.5% below the other data. For R . 1011
