A theoretical and experimental study is performed of rapid, fully developed flows of cohesionless granular materials down inclined chutes with a rough base. Two flow types are studied in detail: (1) immature sliding flow, where a stagnant zone forms on the base of the chute, and (2) fully developed sliding flow, where no such zone is formed. A simple phenomenological theory is developed that pr...

high weissenberg boundary layer flow of viscoelastic fluids on a stretching surface has been studied. the flow is considered to be steady and two dimensional. flows of viscoelastic liquids at high weissenberg number exhibit stress boundary layers near walls. these boundary layers are caused by the memory of the fluid. upon proper scaling and by means of an exact similarity transformation, the n...

In this paper a previously developed theoretical model of the measurement process performed by a transittime ultrasonic anemometer is applied to a fluid flowing through a circular section pipe. This model considers the influence of the shift of the acoustic pulse trajectory from straight propagation due to the flow on the measured speed. The aim of this work is to estimate the errors induced in...

It has long been surmised that the mean-velocity profile (MVP) of pipe flows is closely related to the spectrum of turbulent energy. Here we perform a spectral analysis to identify the eddies that dominate the production of shear stress via momentum transfer. This analysis allows us to express the MVP as a functional of the spectrum. Each part of the MVP relates to a specific spectral range: th...

The branch of fluid mechanics is also familiar with biomechanics recently. The combination of hydrodynamic and mechanical specification of the flow can reach the complex description of the liquid flow in the hydraulic system. The hydraulic system can represent the airways and ventilation system, and external blood circulation. An important role in the study of hemo-transport has its interaction...

This study of aortic root flow velocity profiles suggests that the flow velocity pattern is parabolic rather than flat as has been widely supposed. To analyze the distribution of flow velocity, a special ultrasound pulsed Doppler velocity flow meter, with a direct probe on the aortic wall, was designed. Sixteen patients, none with a diagnosis of aortic valve disease, were examined just before u...

Radial profiles of particle velocities were investigated in a 6.1m high methanol-to-olefins cold model experimental device using a TSI laser Doppler velocimeter. The effect of axial height on flow development was not obvious in fully developed region under the same operating condition. Superficial gas velocity and solid circulating rate had significant influence on particle velocity in the cent...

Two optical techniques are experimentally investigated to measure the shock wave velocity and particle velocity in metals subjected to hyper velocity impacts. Fabry-Perot interferometer based optical system has been developed and used to measure the interface velocity profile of impacted Tantalum-Glass and Aluminum-Glass targets. Optical fibers coupled to fast photodiodes are implemented to mea...

The average concentration of tracers advected from a point source by a multivariate normal velocity field is shown to deviate from a Gaussian profile. The flatness ~kurtosis! is calculated using an asymptotic series expansion valid for velocity fields with short correlation times or weak space dependence. An explicit formula for the excess flatness at first order demonstrates maximum deviation ...