Convective heat transfer and entropy generation in a 3D closed cavity, equipped with adiabatic-driven baffle and filled with CNT (carbon nanotube)-water nanofluid, are numerically investigated for a range of Rayleigh numbers from 103 to 105. This research is conducted for three configurations; fixed baffle (V = 0), rotating baffle clockwise (V+) and rotating baffle counterclockwise (V−) and a r...

Abstract

Weakly rotating turbulent Rayleigh-Bénard convection was studied experimentally and numerically. With increasing rotation and large enough Rayleigh number a supercritical bifurcation from a turbulent state with nearly rotation-independent heat transport to another with enhanced heat transfer is observed at a critical inverse Rossby number 1/Roc approximately 0.4. The strength of the large-scale...

Bounds for the bulk heat transport in Rayleigh-Benard convection for an infinite Prandtl number fluid are derived from the primitive equations. The enhancement of heat transport beyond the minimal conduction value (the Nusselt number Nu) is bounded in terms of the nondimensional temperature difference across the layer (the Rayleigh number Ra) according to Nu ≤ c Ra where c < 1 is an absolute co...

Complex rotating machine trains especially trains including electric machines are subject to the most varied and often most severe torsional disturbances. If shaft or rotating component failures occur as a result of torsional oscillations, the consequences can be catastrophic. In this paper a comprehensive model and simulation method using analytical formulations are developed to study both ste...

Abstract In view of the problems such as difficulty in and high cost vibration signal collection rotating mechanical shaft, this paper proposes a low-cost, fast, stable reliable hydraulic turbine wheel online monitoring scheme specially designed to imbalance dynamic balance counterweight shaft. Three high-frequency wireless acceleration sensors are installed on shaft monitor signals three direc...