In immiscible two-phase flows, the contact line denotes the intersection of the fluid– fluid interface with the solid wall. When one fluid displaces the other, the contact line moves along the wall. A classical problem in continuum hydrodynamics is the incompatibility between the moving contact line and the no-slip boundary condition, as the latter leads to a non-integrable singularity. The rec...

In a turbulent boundary layer over a smooth flat plate with zero pressure gradient, the intermediate structure between the viscous sublayer and the free stream consists of two layers: one adjacent to the viscous sublayer and one adjacent to the free stream. When the level of turbulence in the free stream is low, the boundary between the two layers is sharp, and both have a self-similar structur...

In recent years, hybrid absorption systems have been implemented which achieve high sound absorption over a broad frequency range. This work is an experimental study of a broadband hybrid absorption system which is comprised of a layer of sound-absorbing material ~the passive component! positioned at a distance from a movable wall ~the active component! inside an impedance tube. The movable wal...

In the current work, a three-dimensional geometry of a 75% stenosed blood vessel is analyzed. Large eddy simulation (LES) with the help of a dynamic subgrid scale Smagorinsky model is applied to model the turbulent pulsatile flow. The geometry, the transmural pressure and the properties of the blood and the elastic boundary were based on clinical measurement data. For the flexible wall model, a...

Theories of the acoustic impedance of micro perforated panels and membranes for normally incident waves have been well developed for decades. These theories are mainly based on the assumption that the particle velocity at the boundary of the hole wall is equal to zero. This assumption is valid when the panel/membrane is massive and does not vibrate. This paper aims to investigate the effects of...

Using evanescent wave microscopy to study near-surface, semi-dilute polymer solution flows provides simultaneous access the mechanical behaviour of liquid and boundary condition at interfaces. Our results highlight importance electrostatic interactions between polymers bounding wall.

The study of boundary layer flow and heat transfer of an electrically conducting visco-elastic second grade fluid in a porous medium past a stretching sheet is conducting with power law surface temperature or power law surface heat flux. The flow in boundary layer is considered to be generated solely by the linear stretching of the boundary sheet adjacent to porous medium in a magnetic field wi...

in this research, the charged system search (css) and enhanced charged system search (ecss) algorithm are used to obtain the optimum design of irregular grillage systems with different spacing and various boundary conditions. the cross-sectional properties of the beams are selected as the design variables and the weight of structure is used as the objective function. the displacement limitation...

The spectral properties of curved quantum wires with Dirichlet boundary condition were widely investigated (e.g. [1], [2], [3]). It was shown that any small curvature of the tube in dimensions 2 and 3 produces at least one positive eigenvalue below the essential spectrum threshold. The problem of the existence of such eigenvalues in the straight quantum waveguides with a combination of Dirichle...

The heat transfer equation of oil, pipe wall and soil, combining with the boundary condition, connection condition and initial conditions to be the differential equations which can simulate the temperature drop rule of hot oil pipeline. Then the numerical solution method is used to solve, constructed difference equations. By the gauss elimination method, the temperature changing rule of hot oil...