In this note we develop and analyze a system of equations describing a molten linear polymer being extruded in a capillary rheometer which is operating under the controlled condition that the mean velocity at the capillary inlet is maintained at a constant value. Slipping of the melt at the pipe wall is permitted and an evolution equation for the boundary slip parameter is postulated. The combi...

In this chapter we present a new method for simulating the motion of a disperse particle phase in a carrier gas through porous media. We assume a sufficiently dilute particle-laden flow and compute, independently of the disperse phase, the steady laminar fluid velocity using the Immersed Boundary (IB) method. Given the velocity of the carrier gas, the equations of motion for the particles exper...

The no-slip boundary condition, i.e., zero fluid velocity relative to the solid at the fluid-solid interface, has been very successful in describing many macroscopic flows. A problem of principle arises when the no-slip boundary condition is used to model the hydrodynamics of immiscible-fluid displacement in the vicinity of the moving contact line, where the interface separating two immiscible ...

The steady two-dimensional flow of a viscous nanofluid of magnetohydrodynamic (MHD) flow and heattransfer characteristics for the boundary layer flow over a nonlinear stretching sheet is considered. Theflow is caused by a nonlinear stretching sheet with effects of velocity, temperature and concentrationslips. Problem formulation is developed in the pre...

We consider 3D Navier-Stokes flows with no-slip boundary condition in an infinitely long pipe with circular cross section. The velocity fields we consider are independent of the variable parametrizing the axis of the pipe, and the component of the velocity normal to the axis is arranged to be circularly symmetric, though we impose no such symmetry on the component of velocity parallel to the ax...

The development of rotor flow associated with mountain lee waves is investigated through a series of highresolution simulations with the nonhydrostatic Coupled Ocean–Atmospheric Mesoscale Prediction System (COAMPS) model using free-slip and no-slip lower boundary conditions. Kinematic considerations suggest that boundary layer separation is a prerequisite for rotor formation. The numerical simu...

A series of experiments are presented which study the flow kinematics of water past drag-reducing superhydrophobic surfaces. The ultrahydrophobic surfaces are fabricated from silicon wafers using photolithography and are designed to incorporate precise patterns of micrometer-sized ridges aligned in the flow direction. The ridges are made hydrophobic through a chemical reaction with an organosil...

The steady three-dimensional boundary layer flow and heat transfer of a dusty fluid towards a stretching sheet with convective boundary conditions is investigated by using similarity solution approach. The free stream along z-direction impinges on the stretching sheet to produce a flow with different velocity components. The governing equations are reduced into ordinary differential equations b...

We investigate the effects of boundary conditions on the surface of self-propelled spherical swimmers moving in a viscous fluid with a low Reynolds number. We first show that collisions between the swimmers are impossible under the commonly used no-slip conditions. Next we demonstrate that collisions do occur if the more general Navier boundary conditions, allowing for a finite slip on the surf...

in this paper, dynamic analysis of the composite truncated sandwich conical shells (stcs) with various boundary conditions subjected to low velocity impact was studied analytically, based on higher order sandwich panel theory. impact was assumed to occur normally over to the top face-sheet and the contact force history is predicted using two solution models of the motion are derived based on ha...