Laminar and Turbulent Flow. If a fluid flows through a long, smooth-walled, narrow tube at a low flow rate, flow is likely to be “laminar.” Here the particles of fluid travel parallel to the sides of the tube. This is often the case for blood flowing in veins. Flow is proportional to the pressure difference (Figure 2A). The viscosity of the fluid is an important determinant of the relationship ...

Arterial stenosis, for example Atherosclerosis, is one of the most serious forms of arterial disease in the formation of which hemodynamic factors play a significant role. In the present study, a 3-D rigid carotid artery with axisymmetric stenosis with 75% reduction in cross-sectional area is considered. Laminar blood flow is assumed to have both Newtonian and non-Newtonian behavior (generalize...

This paper describes laminar fluid flow through a three-dimensional elastomeric microstructure formed by two microfluidic channels, fabricated in layers that contact one another face-to-face (typically at a 90 degree angle), with the fluid flows in tangential contact. There are two ways to control fluid flow through these tangentially connected microchannels. First, the flow profiles through th...

In vortex motion fluid moves in curve path and the stream lines are curved. When the fluid flows between curved stream line, the centrifugal forces are setup which is counter balanced by pressure forces acting in the radial direction. The vortex motion has two types of curved motion. The first type called free vortex type, the fluid moves due to its own natural effect but energy is not added to...

Despite recent development of computational fluid dynamics (CFD) research, analysis of computational fluid dynamics of cerebral vessels has several limitations. Although blood is a non-Newtonian fluid, velocity and pressure fields were computed under the assumptions of incompressible, laminar, steady-state flows and Newtonian fluid dynamics. The pulsatile nature of blood flow is not properly ap...

This paper presents an effective quasi one-dimensional (1-D) computational simulation methodology and some important results for steady annular/stratified (or film wise) internal condensing flows of pure vapor. Though the approach is strictly valid for smooth, laminar vapor/laminar condensate flows, it is also approximately valid for laminar condensate and turbulent vapor which are laminar in t...

The basis of this paper is the assumption, that graviton is a measurable entity of molecular gravitational acceleration and this is not a hypothetical entity. The adoption of this assumption as an axiom is tantamount to fully opening the previously locked door to the boundary theory between laminar and turbulent flows. It leads to the theorem, that the division of flows of Newtonian (viscous) f...

In this paper, implementation of an extended form of a no-slip wall boundary condition is presented for the three-dimensional (3-D) lattice Boltzmann method (LBM) for solving the incompressible fluid flows with complex geometries. The boundary condition is based on the off-lattice scheme with a polynomial interpolation which is used to reconstruct the curved or irregular wall boundary on the ne...

Laminar-to-turbulent transition of pipe flows occurs, for sufficiently high Reynolds numbers, in the form of slugs. These are initiated by disturbances in the entrance region of a pipe flow, and grow in length in the axial direction as they move downstream. Sequences of slugs merge at some distance from the pipe inlet to finally form the state of fully developed turbulent pipe flow. This format...