To understand the friction stir welding process, it is very important to know the nature of the material flow in and around the tool. The process is a combination of both thermal as well as mechanical work i.e. it is a coupled thermo-mechanical process. Numerical simulations are very much essential in order to obtain a complete knowledge of the process as well as the physics underlying it. In t...

secondary flow investigation could be regarded as an important issue in open channel flow, in spite of its lower quantity compared to the base flow in the water course. it should be given special consideration because of the influence on some hydraulic factors in open channel, specifically in compound channels. in compound channels' due to the difference in the flow velocity of the main ch...

Both canopy flow and porous media theories have been developed independent of one another to predict flow through submerged porous structures. These approaches are very similar, albeit with some key differences in how canopy resistance forces are parameterized. Canopy models provide a means of parameterizing the shear stresses that occur at the top of the canopy, whereas porous media models can...

At the cellular scale, blood fluidity and mass transport depend on the dynamics of red blood cells in blood flow, specifically on their deformation and orientation. These dynamics are governed by cellular rheological properties, such as internal viscosity and cytoskeleton elasticity. In diseases in which cell rheology is altered genetically or by parasitic invasion or by changes in the microenv...

Direct numerical simulation of uniform shear flow is used to study the anisotropy of fluctuating motion in a stably stratified medium with uniform mean shear. Turbulence is found to be three dimensional over a wjde range of gradient Richardson numbers in the two Bows investigated here: vertical mean shear ($$-) and horizontal mean shear (g). The role of the turbulent F’roude number in establish...

The viscosity of lipid bilayer membranes plays an important role in determining the diffusion constant of embedded proteins and the dynamics of membrane deformations, yet it has historically proven very difficult to measure. Here we introduce a new method based on quantification of the large-scale circulation patterns induced inside vesicles adhered to a solid surface and subjected to simple sh...

An analysis of low order mode coupling equations is used to describe the nonlinear behavior of the RayleighTaylor (RT) instability in the equatorial ionosphere. The nonlinear evolution of RT instability leads to the development of shear flow. It is found that there is an interplay between the nonlinearity and the shear flow which compete with each other and saturate the RT mode, both in the col...