Analysis of turbulent flow through a square-sectioned duct with installed 90-degree elbow

This paper presents the results of a theoretical and experimental investigation of the flow of air through a square-sectioned duct with installed bend. A special test stand was built which allowed testing two different bends with dimensionless mean radius values 2.01 and 1.5. To measure the volumetric flow rate, a measuring orifice plate was installed for control purposes. Additionally, numerical integration of the continuity equation, equations of motion, and equations of selected turbulence models was carried out using FLUENT. As a result of the numerical calculations, time-averaged velocity fields, pressures, and components of the turbulent stress tensor in a developing hydrodynamic flow through a square-sectioned duct with installed bend were determined. The numerical results obtained were subjected to detailed verification by comparison with experimental results obtained on the constructed test stand and those available in the literature.

► Pressure difference measurement in a flow through a square-sectioned bend is described.
► The numerical modeling tested turbulent flows in a large-curvature bend experimentally.
► The results obtained were used to identify the fluid flow rate using the bend.
► Flow rate indirect measurement in a square-sectioned duct with the installed bend is considered.
► Practical advice is given on designing elbow flow meters installed in square-sectioned ducts.