We perform a quasinormal mode analysis of black-hole configurations in Bose-Einstein condensates (BECs). In this analysis we use the full Bogoliubov dispersion relation, not just the hydrodynamic or geometric approximation. We restrict our attention to one-dimensional flows in BECs with steplike discontinuities. For this case we show that in the hydrodynamic approximation quasinormal modes do n...

The hydrodynamic model of electron transport in semiconductors is analyzed and in analogy to fluid mechanics the transport equation for the electron vorticity, ∇×v, is derived. Aside from the classical hydrodynamic sources of vorticity, collision terms in the continuity and momentum equations may also generate electron vorticity. A scale analysis of the electron vorticity equation is performed ...

a lattice boltzmann method is applied to demonstrate the comparison results of simulating natural convection in an open end cavity using different hydrodynamic and thermal boundary conditions. the prandtl number in the present simulation is 0.71, rayleigh numbers are 104,105 and 106 and viscosities are selected 0.02 and 0.05. on-grid bounce-back method with first-order accuracy and non-slip met...

an attempt is made for the first time to solve the quadratic and cubic model of magneto hydrodynamic poiseuille flow of phan-thein-tanner (ptt). series solution of magneto hydrodynamic (mhd) flow is developed by using homotopy perturbation method (hpm). results are presented graphically and the effects of non-dimensional parameters on the flow field are analyzed. the results obtained reveals ma...

This paper describes self-assembly of millimeter-sized, magnetized disks floating on a liquid-air interface, and rotating under the influence of a rotating external magnetic field. Spinning of the disks results in hydrodynamic repulsion between them, while the rotating magnetic field produces an average confining potential acting on all disks. The interplay between hydrodynamic and magnetic int...

Nowadays, due to the increasing power of diesel engines, especially heavy duty diesel engines, and increasing gas pressure inside the combustion chamber, the forces acting on the engine bearings have dramatically raised. On the other hand, becaus eof the competition in the market, it is necessary to increase the engine bearing life and reduce its failure as much as possible. The engine bearings...