one of the popular and well known models in boundary layer that is implemented in most of the operational and familiar models is the mellor-yamada model of atmospheric boundary layer. one reason that this model is so popular is its ability in simulations and exposing of different phenomena in the boundary layer. this model has been constructed based on second order closure hypothesis. beside al...

Laser Doppler Velocimetry (LDV) has been employed to determine pseudo-turbulence characteristics of the flow field around bubble train forming in non-Newtonian caboxymethylcellulose (CMC) aqueous solution at low gas flow rate condition. The Reynolds stress and turbulent intensity of the liquid were investigated by means of Reynolds time-averaged method. The experimental results show that ax...

In this paper, an enhancement design of communication system using optical radio frequency (RF) waves in free space optical communication (FSO) system is presented. To our knowledge, it is the first time that the effect of Gamma-Gamma turbulent channel model on the performance of the proposed system is analyzed and simulated. To obtain an optical communication system with good performance and h...

A detection method based on sensitization of a squared double differentiated signal is developed which discriminates the turbulent zones from laminar zones quite accurately. The procedure adopts a variable threshold and a variable hold time of the order of the Kolmogorov time scale. The output file so generated, includes all the information for further analysis of the turbulent signal.

Context. The mean-field theory of magnetized stellar convection gives rise to two distinct instabilities: the large-scale dynamo instability, operating in the bulk of the convection zone and a negative effective magnetic pressure instability (NEMPI) operating in the strongly stratified surface layers. The latter might be important in connection with magnetic spot formation. However, as follows ...

In this paper the flow behaviour over a number of car bodies is studied. For this purpose the unsteady 2-D incompressible Navier-Stokes equations have been applied. After averaging and nondimensionalizing the equations, the system of equations has been transformed from the Cartesian (x-y) coordinates to a body fitted generalized (-) coordinate. As the flow is incompressible, the density in the ...

Transition phenomena between thermal noise state and turbulent state observed in a submarginal turbulent plasma are analyzed with statistical theory. Time-development of turbulent fluctuation is obtained by numerical simulations of Langevin equation which contains hysteresis characteristics. Transition rates between two states are analyzed. Transition from turbulent state to thermal noise state...

Turbulent wake is crucial for the visually appealing effects of liquid. Unfortunately, it is challenging to realistically simulate this phenomenon with ring-shaped vortical structures. To tackle this issue, we propose a filament-based turbulent wake synthesis method for realistically simulating the turbulent wake with ring-shaped vortical structures. The filaments are sampled at the separation ...

Shear stress on blood cells and platelets transported in a turbulent flow dictates the fate and biological activity of these cells. We present a theoretical link between energy dissipation in turbulent flows to the shear stress that cells experience and show that for the case of physiological turbulent blood flow: (a) the Newtonian assumption is valid, (b) turbulent eddies are universal for the...