Observations, and laboratory and numerical studies, of fluid flows with strong rotation and thermal forcing often show long-lived convective Taylor columns (CTCs) which carry a large portion of the vertical heat and mass fluxes. However, owing to experimental and numerical challenges, these structures remain poorly understood. Here we present a nonlinear, analytical multiscale model of CTCs in ...

We present experimental heat transport measurements of turbulent Rayleigh-Bénard convection with rotation about a vertical axis. The fluid, water with a Prandtl number (sigma) of about 6, was confined in a cell with a square cross section of 7.3 x 7.3 cm2 and a height of 9.4 cm. Heat transport was measured for Rayleigh numbers 2 x 10(5)<Ra<5 x 10(8) and Taylor numbers 0<Ta<5 x 10(9). We show th...

We present a study of dynamical scaling and domain growth in a non potential system that models Rayleigh–Bénard convection in a rotating cell. In d = 1, dy-namical scaling holds, but the non potential terms modify the characteristic growth law with a crossover from logarithmic to linear in time. In d = 2 the non potential terms prevent coarsening for any value of the angular rotation speed.

Heat transfer in a Rayleigh-Bénard configuration consisting of a vertical cylinder, which is rotating about its axis, can be intensified considerably when the rotation rate is modulated harmonically in time. Such time-dependent rotation introduces an Euler force into the governing equations which leads to a particular modification of the flow that is shown to support a Nusselt number (Nu) that ...

We present local temperature measurements of turbulent Rayleigh-Bénard convection with rotation about a vertical axis. The fluid, water with Prandtl number about 6, was confined in a cell with a square cross section of 7.3×7.3 cm(2) and a height of 9.4 cm. Temperature fluctuations and boundary-layer profiles were measured for Rayleigh numbers 1×10(7)<Ra<5×10(8) and Taylor numbers 0<Ta<5×10(9). ...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

The onset of convection in the form of magneto-inertial waves in a rotating fluid sphere permeated by a constant axial electric current is studied through a perturbation analysis. Explicit expressions for the dependence of the Rayleigh number on the azimuthal wavenumber are derived in the limit of high thermal diffusivity. Results for the cases of thermally infinitely conducting and of nearly t...

The rotating shaft is the key component of air compressor connecting bearing seat and turbine disk for hydrogen battery, its working reliability affects safety compressor.The energy battery disk, life compressor. performance analysis comparison typical structure an are carried out, which provides experimental data vibration lays a theoretical foundation relevant design enterprises.

Roller bearings are important elements of high performance mechanical systems, as they support the rotating parts and they reduce the contact friction. Therefore, it is necessary to continuously monitor their performance using non-destructive diagnostic methods. These methods interrogate data signals acquired during the machines operation. In this paper, the method of Hilbert – Huang transform ...

The governing equations of an initially stressed, rotating and transversely isotropic thermoelastic solid permeated with magnetic field are solved for surface wave solutions. The appropriate particular solutions in the half-space satisfy the required boundary conditions at a thermally insulated stress free surface. A velocity equation is obtained for wave speed of thermo-elastic Rayleigh wave. ...