Research Highlights
Congratulation to Prof. Subhasish Dey for publishing a research paper titled "Effects of U-burrow bioirrigation on turbulence characteristics" in Journal of Hydraulic Research
Abstract
Large eddy simulation (LES) was carried out to study the effects of the U-burrow density and bioirrigation intensity on the turbulence characteristics in an open-channel flow. Results reveal that near the bio-microtopography, the combined effect of the main flow and bioirrigation produces a backflow vortex in the U-burrow and at its outlet, helping the benthos to obtain nutrients. Meanwhile, the biological jet flow increases the bed roughness. The peaks in the Reynolds shear stress (RSS) and turbulent kinetic energy (TKE) distributions near the U-burrow increase significantly with an increase in bioirrigation intensity, while those at the outlet of the U-burrow decrease initially and then increase with an increase in U-burrow density. Then, the effects of bioturbulence intensity and U-burrow density can be summarized as a dimensionless Bin. The equivalent roughness heights and Darcy–Weisbach friction factor are observed to be proportion to Bin, for which two formulas are recommended.
