This work examines the slip boundary condition by Lattice Boltzmann simulations, addresses the validity of the Navier’s hypothesis that the slip velocity is proportional to the shear rate and compares the Lattice Boltzmann simulations to the experimental results of Tretheway and Meinhart (Phys. of Fluids, 14, L9-L12). The numerical simulation models the boundary condition as the probability, P,...

We consider models in which a dark-matter particle decays to a slightly less massive daughter particle and a noninteracting massless particle. The decay gives the daughter particle a small velocity kick. Selfgravitating dark-matter halos that have a virial velocity smaller than this velocity kick may be disrupted by these particle decays, while those with larger virial velocities will be heated...

‎the problem of two-phase mhd boundary layer flow, heat and mass transfer over a stretching sheet with fluid-particle suspension and thermal radiation has been studied. the effect of mass transfer in dusty fluid over a stretching sheet is considered for the first time. the governing equations are reduced to a set of non-linear ordinary differential equations under suitable similarity transforma...

This paper addresses erosion prediction in 3-D, 90° elbow for two-phase (solid and liquid) turbulent flow with low volume fraction of copper. For a range of particle sizes from 10 nm to 100 microns and particle volume fractions from 0.00 to 0.04, the simulations were performed for the velocity range of 5-20 m/s. The 3-D governing differential equations were discretized using finite volume metho...

Laboratory experiments have recently confirmed that the streamwise particle velocity is largely less than that of the fluid in sediment-laden flows. This velocity lag is investigated analytically in the present study based on the drag force exerting on a particle in the presence of other neighbors. The normalized drag force or the hindrance coefficient is found generally dependent on the partic...

In stingless bees, recruitment of hive bees to food sources involves thoracic vibrations by foragers during trophallaxis. The temporal pattern of these vibrations correlates with the sugar concentration of the collected food. One possible pathway for transferring such information to nestmates is through airborne sound. In the present study, we investigated the transformation of thoracic vibrati...

In the present study, a theoretical model was used to examine factors affecting the filtration characteristics of filters used for respiratory protection. This work was designed to support the particulate filter test requirements established in 1996. The major operating parameters examined in this work include face velocity, fiber diameter, packing density, filter thickness, and fiber charge de...

the local solid flow structure of gas-solid bubbling fluidized bed was investigated to identify and characterize the particle clusters. extensive mathematical calculations were carried out using the energy-minimization multi-scale (emms) approach for evaluating cluster properties including the velocity, the size and the void fraction of clusters in the dense phase of the bed. the results showed...

Two-dimensional Lagrangian trajectories of the inertial particle in helium II are analyzed in the vicinity of the triple vortex structure (i.e. the superfluid vortex and the normal dipole-like vortex structure induced by the mutual friction). It is shown that the vortices in the normal fluid can deflect the particle which otherwise would have collided with the superfluid vortex and, provided th...

Accurate prediction of particle deposition in airliner cabins is important for estimating the exposure risk of passengers to infectious diseases. This study developed a Detached-Eddy Simulation (DES) model with a modified Lagrangian method. The computer model was validated with experimental data for particle deposition in a cavity with natural convection and with air velocity, air temperature, ...