Studying subcritical opposing channel flows

Abstract

This study investigates the hydraulics of opposing open channel flow (OCF) by using computational fluid dynamics software – Fluent. The model is validated with the velocity fields, flow separation zone, and water surface elevation obtained from experimental study available in the literature. 3D flow structures and turbulence characteristics of the validation problem are also discussed. In total, 81 cases of opposing flows are studied varying the discharge ratio, Froude number at the exit, the width ratio, and the aspect ratio of the exit channel. Simulated results are used to develop empirical equations for contraction coefficient, flow depth ratio, and minimum water depth in the contracted section of the OCF. The energy loss coefficient is computed from the simulated results. Contraction coefficient, flow depth ratio, and energy loss coefficient of OCF and corresponding values of right-angled channel junction flows are compared.

KEYWORDS:

• Computational fluid dynamics
• energy loss
• separation zone
• opposing channel flow
• turbulence

Acknowledgements

The authors acknowledge the financial help by Prime Minister Research Fellowship and Indian Institute of Technology Gandhinagar to conduct this study.

Additional information

Notes on contributors

Abhishek Kumar Pandey

Abhishek Pandey is a Ph.D. student in Indian Institute of Technology Gandhinagar, India. His research areas include computational fluid dynamics, open channel hydraulics, sediment transport, and turbulence. He completed his BTech from National Institute of Technology Patna, India in 2016. After completing his Bachelor degree in civil engineering, he joined IIT Gandhinagar in the same year.

Pranab Kumar Mohapatra

Pranab Mohapatra is a professor in Institute of Technology Gandhinagar, India. Earlier, he was a professor in Indian Institute of Technology Kanpur, India. His research areas are Hydraulics and water resources engineering, Transients in pipe flow, Transients in open channel flow, Frequency domain analysis in pipe flow.

Vikrant Jain

Vikrant Jain is a professor in Institute of Technology Gandhinagar, India. His research areas are Earth surface processes, River science, External forcings and river’s future, Glacio-fluvial coupling, geomorphic applications in stream management.

Udit Bhatia

Udit Bhatia is an assistant professor in Institute of Technology Gandhinagar, India. His research areas are Critical Infrastructure Resilience, Network Science, Ecological Dynamics, Machine Learning, Climate Variability and Change.