![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
ABSTRACT
A complex flow pattern occurring in a circular conduit bend with supercritical flow has been studied. The main objective was to obtain reliable criteria for prediction of the onset of helical and choking flow, in order to facilitate the design of bottom outlets, tunnel spillways and drainage collectors with bends. A series of scale model experiments provided data for developing empirical relationships describing the effects of the bend curvature, bend deflection angle and approach flow conditions (relative flow depth and Froude number) on the inception of helical and choking flow. Expressions for the energy bend loss coefficient were also proposed. The bend curvature and approach flow conditions proved to have a major influence on the onset of helical flow, while the deflection angle becomes an important parameter for angles less than 45°. Bend curvature and deflection angle have commensurable influence on the onset of choking flow.
Funding
The authors acknowledge the financial support through the projects TR 37009 and TR 35043, funded by the Serbian Ministry of Education, Science and Technological Development.