introduction: for a velocity profile in turbulent flows, the flow conditions in the vicinity of the wall are described by logarithmic law of the wall. however, it has been extensively verified that the log-law does not apply in the outer region of the boundary layer. for example, in free surface flows, the law of the wall holds only for 20 percent of the flow depth from the wall. coles (1956) c...

introduction: due to sensitiveness of flow to roughness coefficient (rc), selection of this coefficient is important in earth canals designing purposes. precision selection of this coefficient is necessary for design and operation of earthen canals purposes. overestimation of the actual amount of this coefficient will cause an underestimation for flow velocity. accordingly, sedimentation in the...

this study is concerned with the prediction of particles’ velocity in a dilute turbulent gas-solidboundary layer flow using a fully eulerian two-fluid model. the closures required for equationsdescribing the particulate phase are derived from the kinetic theory of granular flows. gas phaseturbulence is modeled by one-equation model and solid phase turbulence by mlh theory. resultsof one-way and...

in order to identify left ventricular diastolic function in patients with betathalassemia major and normal systolic function by noninvasive m-mode and doppler echocardiography, an analytic study was designed in a university hospital in sari. we have studied 44 patients (23 men and 21 women), mean age 15.48±2.16 (range 12 to 20) and 43 age and sex matched control subjects. peak flow velocity in ...

an analytical study was performed to study effects of thermo-diffusion and chemical reactions on a three-dimensional mhd mixed convective flow of dissipative fluid along an infinite vertical porous plate with transverse sinusoidal suction velocity. the parabolic partial differential equations governing the fluid flow, heat transfer, and mass transfer were solved using perturbation technique and...

Unsteady slip-flow of second grade non-Newtonian electrically conducting fluid over an oscillating sheet has been considered and solved numerically. A second-order slip velocity model is used to predict the flow characteristic past the wall. With the assumption of infinite length in x-direction, velocity of the fluid can be assumed as a function of y and t, hence, with proper variable change pa...

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...