Numerical simulations of large aspect ratio, three-dimensional rotating Rayleigh-Bénard convection for no-slip boundary conditions have been performed in both cylinders and periodic boxes. We have focused near the threshold for the supercritical bifurcation from the conducting state to a convecting state exhibiting domain chaos. A detailed analysis of these simulations has been carried out and ...

Numerical studies of the domain chaos state in a model of rotating Rayleigh-Bénard convection suggest that finite size effects may account for the discrepancy between experimentally measured values of the correlation length and the predicted divergence near onset.

In this study, rotating flexible shaft-disk system having flexible beams is considered as a dynamic system. After neglecting nonlinear terms, torsional vibration of the shaft-disk system and lateral and longitudinal vibration of the flexible beam are still coupled through the motor speed. The system has three natural frequencies; the flexible shaft-disk system torsional natural frequency, the f...

In this paper, an exact analytical solution for free vibration of rotating bi-layered cylindrical shell composed of two independent functionally graded layers was presented. The thicknesses of the shell layers were assumed to be equal and constant. The material properties of the constituents of bi-layered FGM cylindrical shell were graded in the thickness direction of the layers of the shell ac...

The conditions that strain energy tensor and necessary condition on the roots of a constitutive equation must be positive definite produces some inequalities. These inequalities reduce the number of Rayleigh waves in orthotropic and transversely isotropic materials. Some earlier published work is found to be erroneous.

A combined analytical, numerical, and experimental study of the traveling-wave wall mode in rotating Rayleigh-Bénard convection is presented. No-slip top and bottom boundary conditions are used for the numerical computation of the linear stability, and the coefficients of the linear complex Ginzburg-Landau equation are then computed for various rotation rates. Numerical results for the no-slip ...

An apparatus to simulate the thermal behavior of a 3/4 inch bore tapered roller bearing was constructed and used to determine tapered roller bearing thermal behavior. Bearing specimens can be loaded axially and/or radially while rotating. Shaft heating is also provided and mechanical losses measured. An infrared scanner and thermocouples allow for temperature measurement. An analytical model of...

This paper deals with mathematical modelling of nonlinear vibration of large rotating shaft systems with gears and rollingelement bearings. Gearing and bearing couplings bring into the system nonlinear phenomena like impact motions due to the possibility of the mesh interruption. The motion of the system is influenced by the internal kinematic excitation in gearing and by the parametric excitat...

A magnetic bearing is a bearing which supports a load using magnetic levitation. Magnetic bearings support moving machinery without physical contact, for example, they can levitate a rotating shaft and permit relative motion without friction or wear. In active magnetic bearings (AMB) a stable equilibrium is achieved by means of one or more control loops. The use of control loop for maintaining ...