Purpose – This paper aims to examine how using lattice Boltzmann method (LBM) aids the study of the isothermal-gas flow with slight rarefaction in long microtubes. Design/methodology/approach – A revised axisymmetric lattice Boltzmann model is proposed to simulate the flow in microtubes. The wall boundary condition combining the bounce-back and specular-reflection schemes is used to capture the...

This paper addresses the combined effects of couple stresses, thermal radiation, viscous dissipation and slip condition on a free convective flow of a couple stress fluid induced by a vertical stretching sheet. The Cogley- Vincenti-Gilles equilibrium model is employed to include the effects of thermal radiation in the study. The governing boundary layer equations are transformed into a system o...

Slip along a frictional contact between elastic bodies can be stable or unstable, leading to stick-slip motion. Frictional slip also associated with vibrations. The condition for these vibrations and their characteristics remains poorly understood. To address this issue, which is relevant engineering earth science, we carry out linear stability analysis of spring-and-slider system obeying rate ...

The composite torsional ultrasonic oscillator, a versatile experimental system, can be used to investigate slip of a Newtonian fluid at a smooth surface. A rigorous analysis of slip-dependent damping for the oscillator is presented. Initially, the phenomenon of finite surface slip and the slip length are considered for a half space of Newtonian fluid in contact with a smooth, oscillating solid ...

The hydrodynamics of a flagellated microorganism is investigated when swimming close to a planar free-slip surface by means of numerical solutions of the Stokes equations obtained via a Boundary Element Method. Depending on the initial condition, the swimmer can either escape from the free-slip surface or collide with the boundary. Interestingly, the microorganism does not exhibit a stable orbi...

A variety of commercially available cane and crutch tips were tested on surfaces of ice and soapy tile under varying axial (thrust) loads. The output measurement consisted of the angle between the vertical and the cane axis at which slip occurred. It was learned that: 1. From the viewpoint of a user, a minimal slip angle of roughly 25 deg is desirable. 2. On ice-rink ice, a number of cane tips ...

When we manipulate small objects, our fingertips are generally subjected to tangential torques about the axis normal to the grasp surface in addition to linear forces tangential to the grasp surface. Tangential torques can arise because the normal force is distributed across the contact area rather than focused at a point. We investigated the effects of tangential torques and tangential forces ...