New cryogenic nitrogen facility for Rayleigh-Bénard convection at high Rayleigh number - Part 2: Validation and Initial Data*

We present initial results from our newly constructed cryogenic nitrogen facility for studying Rayleigh Bénard convection at high Rayleigh numbers. Our validation experiments cover the Rayleigh number range 10⁸ ≤ Ra ≤ 10¹³, and order-unity Prandtl number in a test cell of unity aspect ratio (diameter-to-height ratio). The Nusselt number scaling for this range is compared with other experimental data. Additionally, we outfit the test cell with fast response thermistors in the bulk of the flow, and show initial fluctuation data over an extended range of Rayleigh numbers.