Influences of Momentum Ratio on Transverse Dispersion for Intermediate-Field Mixing Downstream of Channel Confluence

Jaehyun Shin, Sunmi Lee and Inhwan Park ()
Additional contact information
Jaehyun Shin: Department of Civil and Environmental Engineering, Gachon University, Seongnam-si 13120, Republic of Korea
Sunmi Lee: Department of Civil Engineering, Seoul National University of Science and Technology (SeoulTech), Seoul 01811, Republic of Korea
Inhwan Park: Department of Civil Engineering, Seoul National University of Science and Technology (SeoulTech), Seoul 01811, Republic of Korea

IJERPH, 2023, vol. 20, issue 4, 1-21

Abstract: This study aims to analyze the influences of momentum ratio ( M r ) and confluence angle ( α ) on the transverse dispersion in an urban scale confluence channel from the numerical simulation results using the Environmental Fluid Dynamics Code model. By changing the momentum flux and confluence angle from the simulation results, the analysis focused on the relations between the vertical variations of transverse velocity and transverse dispersion. The high momentum tributary aligned the mixing interface toward the outer bank and created a strong helical motion, which transported the contaminated water along the channel bed and inflows into the recirculation zone. The high momentum ratio induced the large vertical shear in transverse velocity with a strong helical motion and increased the transverse dispersion. However, the helical motion persistence rapidly decreased as the flow reached downstream and led to a decrease in the transverse dispersion for the large confluence angle. Thus, the transverse dispersion coefficient increased with a high momentum ratio and low confluence angle, and the dimensionless transverse dispersion coefficient was in the range of 0.39–0.67, which is observed in meandering channels, for M r > 1 and α = 45°.

Keywords: channel confluence; momentum ratio; confluence angle; transverse dispersion; vertical shear in transverse velocity; helical motion (search for similar items in EconPapers)
JEL-codes: I I1 I3 Q Q5 (search for similar items in EconPapers)
Date: 2023
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1660-4601/20/4/2776/pdf (application/pdf)
https://www.mdpi.com/1660-4601/20/4/2776/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jijerp:v:20:y:2023:i:4:p:2776-:d:1057810

Access Statistics for this article

IJERPH is currently edited by Ms. Jenna Liu

More articles in IJERPH from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().