CFD Investigation of Turbidity Spikes for Different Velocity and Particle load Profiles in a Horizontal Pipe

Abstract

A comprehensive 3D numerical investigation of the behaviour of particles flowing through a horizontal pipe has been studied in this paper. The multiphase mixture module available in the computational fluid dynamics (CFD) model FLUENT 6.2 is used in this study. Five different time-dependent flows and particle-load profiles have been used to simulate particle flow behaviour though the pipeline. The deposition of particles along the pipe has been investigated. The effect of unsteady fluid velocity over particle loads has also been investigated. Results show that after a certain length of pipe and/or travel time, when the velocity becomes steady after a deceleration period, the pipe shear stress is strong enough to cause some particle deposition or rolling along the bottom surface of the pipe wall, creating a secondary accumulation of particles (called shoot). Various velocity and particle load profiles have been considered in the light of real phenomena occurring in Melbourne’s South East Water Ltd distribution network. The paper is expected to help the water authorities in understanding the propagation of turbidity spikes in pipe networks.

Key Words:

• Multiphase
• turbidity spike
• unsteady flow
• suspended solids
• turbulent flow

Additional information

Notes on contributors

A Hossain

Dr Alamgir Hossain is currently serving as Assistant Professor at Military Institute of Science and Technology (MIST), Dhaka, Bangladesh. He also served as Assistant Professor at Prime Asia University, Dhaka, Bangladesh. He graduated from Bangladesh University of Technology in 1999. He received his PhD from Swinburne University of Technology, Melbourne, Australia, in 2005. His expertise is in computational fluid dynamics (CFD).

J Naser

Dr Jamal Naser received his PhD on computational fluid dynamics (CFD) from Imperial College (University of London) in 1990. He was a British commonwealth scholar (1986–1990) and obtained a Japan Promotion of Science Fellowship in 1995. Jamal published more than 100 research papers in international journals and refereed conferences. He has successfully completed supervision of many PhD students and post-doctoral fellows. Currently he is the leader of a CFD research group at Swinburne University of Technology, Hawthorn, Australia.

M Imteaz

Dr Monzur Imteaz is working as a Senior Lecturer within the Civil Engineering Group of Swinburne University of Technology, Melbourne, Australia. He received his BSc in Civil Engineering from Bangladesh University of Engineering & Technology and MEng in Water Resources Engineering from Asian Institute of Technology (Thailand). He secured a Japanese Government Scholarship for doctoral study and completed his PhD in 1997 on lake hydrodynamics, destratification process and water quality modelling from Saitama University. After that he was working as a water quality specialist with Institute of Water Modelling (Bangladesh). He was involved with several projects on flood and drainage studies, and water quality monitoring and modelling in collaboration with Danish Hydraulic Institute (DHI) at Denmark. He has extensive expertise on DHI-developed water and environment software. Later he completed post-doctoral research at the University of Queensland, Brisbane. Before joining Swinburne he has been involved with several Australian local and state government positions in Queensland, New South Wales and Victoria. At Swinburne, Monzur is teaching Sustainable Design, Urban Water Resources and Integrated Water Design subjects. Also, he has been actively involved with various research on sustainability, water recycling, developing decision support tools, integrated catchment-stream-lake water modelling and wastewater treatment.