Flow mode transition and heat transport in confined liquid-metal convection

We present a comprehensive experimental investigation on flow mode transition and heat transport in confined liquid metal convection at a Prandtl number of italic probability equals 0.029 Pr = 0.029 $ \textit{Pr} = 0.029$ , using cylindrical convection cells with aspect ratios upper Gamma equals 1 Γ = 1 $\varGamma = 1$ , 1 divided by 2 1 / 2 $1/2$ and 1 divided by 3 1 / 3 $1/3$ . Whenever comparable data are available, the present low- italic probability Pr $ \textit{Pr}$ results are compared with previous measurements in moderate- italic probability Pr $ \textit{Pr}$ water convection (Xi & Xia, Phys. Fluids vol. 20, 2008, p. 055104; Weiss & Ahlers, J. Fluid Mech. vol. 676, 2011, pp. 5–40). It is found that the single-roll mode (SRM) dominates in the upper Gamma equals 1 Γ = 1 $\varGamma = 1$ and 1 divided by 2 1 / 2 $1/2$ ce