The aim of the present study is deriving an analytical solution to incompressible thermal flow in a micro-Couette geometry in the presence of a pressure gradient using Burnett equations with first- and second-order slip boundary conditions. The lower plate of the micro-Couette structure is stationary, whereas the upper plate moves at a constant velocity. Non-dimensional axial velocity and tempe...

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...

D ow nladed fom In one of the most celebrated examples of the theory of universal critical phenomena, the phase transition to the superfluid state of He belongs to the same three-dimensional (3D) O(2) universality class as the onset of ferromagnetism in a lattice of classical spins with XY symmetry. Below the transition, the superfluid density rs and superfluid velocity vs increase as a power l...

Flow resistance due to vegetation may greatly affect the conveyance of a channel, and thus evaluating the resistance is a critical task in river engineering and restoration. Therefore, flow resistance of natural willows and sedges was studied in a laboratory flume. The aim was to investigate, how type, density and combination of vegetation, flow depth and velocity influence vegetal drag or fric...

This paper presents a comparative study of the critical pickup and saltation velocities of particles in horizontal pipelines for pneumatic conveying design. A comparative study is performed using different existing correlations in the literature for the determination of the minimum velocity of transport as a function of the particle and pipe diameter, particle density, solid mass flow rate and ...

The flow of dilute suspensions in a rotating filter separator consisting of a rigid, porous, polyethylene cylindrical filter rotating within an outer cylindrical shell was studied using laser-based velocity measurement techniques. The centrifugal instability of the Taylor–Couette flow results in toroidal vortices stacked in the annulus. The velocity field of the particles is very similar to tha...

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...