When pulling a particle in a driven granular fluid with constant force Fex, the probe particle approaches a steady-state average velocity v. This velocity and the corresponding friction coefficient of the probe ζ=Fex/v are obtained within a schematic model of mode-coupling theory and compared to results from event-driven simulations. For small and moderate drag forces, the model describes the s...

In real systems, the phenomena, such as pipe-wall viscoelasticity, unsteady friction or fluid structure interaction induce additional damping and dispersion of transient pressure waves than that defined by classical waterhammer. In this paper, unsteady friction models and viscoelastic damping models will be presented and a theoretical formulation of the viscoelastic damping in piping systems wi...

We propose a simple friction model for isolated polymer chains on a solid substrate. The chains are pulled at constant velocity by one end, the other end can be trapped on the solid substrate on localised sites. We focus on the energy dissipation due to the traps. This simple model leads to non trivial friction laws, depending on the velocity and the distance between traps. Some refinements of ...

micro scale gas flows has attracted significant research interest in the last two decades. in this research, the fluid flow of gases in the stepped micro-channel at a wide range of knudsen number has been analyzed with using the lattice boltzmann (mrt) method. in the model, a modified second-order slip boundary condition and a bosanquet-type effective viscosity are used to consider the velocity...

We propose a simple friction model for isolated polymer chains on a solid substrate. The chains are pulled at constant velocity by one end, the other end can be trapped on the solid substrate on localised sites. We focus on the energy dissipation due to the traps. This simple model leads to non trivial friction laws, depending on the velocity and the distance between traps. Some refinements of ...

In the paper we have focused the effect of Hematocrit on flow parameters, such as resistance, frictional resistance, and skin friction due to stenosis in the artery taking blood as non-Newtonian fluid. It has been found that resistance increases with the increasing of hematocrit level and stenosis height. It is also shown that a skin-friction increase with increasing of stenosis height and decr...

When lubricated by synovial fluid, articular cartilage provides some of the lowest friction coefficients found in nature. While it is known that macromolecular constituents of synovial fluid provide it with its lubricating ability, it is not fully understood how two of the main molecules, lubricin and hyaluronic acid, lubricate and interact with one another. Here, we develop a novel framework f...

Relative motion between soft wet solids arises in a number of applications in natural and artificial settings, and invariably couples elastic deformation fluid flow. We explore this in a minimal setting by considering a fluid-immersed negatively buoyant cylinder moving along a soft inclined wall. Our experiments show that there is an emergent robust steady-state sliding regime of the cylinder w...

This paper analyzes the effect of fluid flow characteristics on convection heat transfer for mini-helically coiled tubes (HCT) using supercritical carbon dioxide (CO2) as a natural refrigerant. Two experimental cases have studied in this work at different diameters with coil pitches analyzing resistance. In first case, inner tube diameter, diameter and pitch were 5 mm, 200 mm 10 respectively, w...

In this paper, the slipping friction is considered in the problem of a progressive wave of real fluids propagating over a permeable bottom.In the interface of soil and fluid, the “no-slip” condition is relaxed and a sliding friction coefficient is introduced. Thus, the slipping effect and the permeability of the bottom on the velocity near the seabed can be studied. The results indicate that th...