نتایج جستجو برای: critical flow velocity

تعداد نتایج: 1044144  

2012
Stefan Felder Hubert Chanson

Basic experiments were conducted on a large-size broad-crested weir with a rounded corner. Detailed free-surface, velocity, and pressure measurements were performed for a range of flow conditions. The results showed the rapid flow distribution at the upstream end of the weir and next to the weir brink at large flow rates. The flow properties above the crest were analyzed taking into account the...

Journal: :journal of solid mechanics 0
a.h ghorbanpour arani faculty of mechanical engineering, university of tehran, tehran, iran a rastgoo faculty of mechanical engineering, university of tehran, tehran, iran a. ghorbanpour arani faculty of mechanical engineering, university of kashan, kashan, iran --- institute of nanoscience & nanotechnology, university of kashan, kashan, iran r kolahchi faculty of mechanical engineering, university of kashan, kashan, iran

the high blood rate that often occurs in arteries may play a role in artery failure and tortuosity which leads to blackouts, transitory ischemic attacks and other diseases. however, vibration and instability analysis of carotid arteries are lacking. the objective of this study is to investigate the vibration and instability of the carotid arteries conveying blood under axial tension with surrou...

Journal: :journal of applied research in water and wastewater 2014
hossein bonakdari gislain lipeme-kouyi girdhari lal asawa

the developing turbulent flow in an open channel is a complex three-dimensional flow influenced by the secondary currents and free surface effects and is, therefore, not amenable to analytical solution. this paper aims to study the impact of three key hydraulic parameters (relative roughness, the froude number and the reynolds number) on the establishment length using computational fluid dynami...

2012
Gergely Szirmai

We study the instability of a moving spinor Bose-Einstein condensate when the speed of flow reaches the critical velocity. This we identify on the basis of Landau’s criterion, i.e. the velocity above which some elementary excitation energy becomes negative. We show that the first-to-become unstable excitations are spin-carrying quasiparticles. We also discuss the temperature dependence of the c...

Journal: :تحقیقات مهندسی کشاورزی 0
عبداله ایمان مهر دانشجوی سابق دکتری دانشگاه تربیت مدرس برات قبادیان دانشیار دانشگاه تربیت مدرس سعید مینایی دانشیار دانشگاه تربیت مدرس محمدهادی خوش تقاضا دانشیار دانشگاه تربیت مدرس

a canola seed pneumatic conveyor was designed and constructed to convey canola seed at a 90 g/hr mass flow rate through a 58 mm diameter pipe. physical and aerodynamic properties of the canola seed that are critical to the design process were measured. system pressure drop, comprising air pressure drop and solid pressure drop and which is the most important aspect of pneumatic conveyor design, ...

منوچهر حیدرپور, , حسین افضلی مهر, , سید حسین فرشی, ,

In this study, two data ranges of uniform flow (bulk parameters) and non-uniform flow (local parameters) are employed to investigate resistance to flow and the factors affecting it using velocity distribution of boundary layer theory. The results indicate that the cross-section form factor or adjustment roughness coefficient of logarithmic law can not improve the prediction of flow resistance....

ژورنال: علوم آب و خاک 2003
منوچهر حیدرپور, , حسین افضلی مهر, , سید حسین فرشی, ,

In this study, two data ranges of uniform flow (bulk parameters) and non-uniform flow (local parameters) are employed to investigate resistance to flow and the factors affecting it using velocity distribution of boundary layer theory. The results indicate that the cross-section form factor or adjustment roughness coefficient of logarithmic law can not improve the prediction of flow resistance....

شمال نسب, بابک, فتحی مقدم, منوچهر, مسجدی, علیرضا,

Tamarix sricta plant grows in riversides of Karun river. Outer body plant in the flood times causes decrease in water velocity, preventing erosion. One of the factors by which the hydraulic resistance is expressed is the roughness coefficient. Measurement of roughness coefficient of the existing plants in these riversides and floodplains, and surveying their effects on the velocity decrease and...

ژورنال: علوم آب و خاک 2009
شمال نسب, بابک, فتحی مقدم, منوچهر, مسجدی, علیرضا,

Tamarix sricta plant grows in riversides of Karun river. Outer body plant in the flood times causes decrease in water velocity, preventing erosion. One of the factors by which the hydraulic resistance is expressed is the roughness coefficient. Measurement of roughness coefficient of the existing plants in these riversides and floodplains, and surveying their effects on the velocity decrease and...

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