Working Group on Transient Flows
Vision, scopes and research focuses
Our aim is to provide with a framework to the transient group community within IAHR association. To the date, there are no other international research associations with a specific representation to hydraulic transients. Eventually, our vision is to organize individual IAHR symposiums or conferences on transients and start to have a sub-theme or a theme on transient in future IAHR congress.
The main focus areas of the working group include:
Transient waves theory in hydro-systems
Hydro-system diagnosis by means of transient waves
Waves-structure interaction in hydro-systems
Geysers in storm-water and combined sewer systems
Computational transient flows modeling (in closed or opened conduit flows)
Transient-turbulent flows (in closed or opened conduit flows)
Field works: case studies, practical applications and projects
Upcoming activities
IAHR Online Training Course on Modelling Software for Transient Flows, 24-28 March 2025
Background
Hydraulic transient is known as the rapidly changing flow inducing pressure waves in closed conduits or open channel systems. This engineering field, which is important for system design and recently found to be valuable for system diagnosis, is being studied by over 500 researchers around the world. In fact, the records show that the 2nd most submissions of papers to the Journal of Hydraulic Research (JHR) are in the topic of hydraulic transients (after sediment transport). Unfortunately, none of the current IAHR conferences/symposiums are dedicated to such field, and there has never been a theme or sub-theme on transient flows in past IAHR congresses.
Prof Silvia Meniconi and Prof Moez Louati organized two successful sessions on transient in pipes in IAHR congress in 2017 (KL) and 2019 (Panama). These two special sessions had over 40 participants and included keynote lectures from top professors in hydraulic transients (including Prof. Bryan Karney, Prof. Hanif M. Chaudhry, Prof. Jim Liou, Prof. Bruno Brunone, Prof. Mohamed S. Ghidaoui). This marked a clear indication that there is an interest for a special theme on transient flows that could bring the transient community together within IAHR. Consequently, a request for a working group on transient flows was proposed and accepted in April 2020 to be held under the technical committee on fluid mechanics.
Building on this momentum, additional dedicated sessions were hosted in Granada (2022) and Vienna (2023) and Lisbon (2024). Each attracted more than 50 participants, and featured insightful keynote lectures by experts such as Arris Tjsseling, Hanif Chaudhry, and Bruno Brunone.
Figure 1 Prof. Bryan Karney during his keynote lecture in the 38th IAHR World congress, Panama
Figure 2 A good selection of the transient group during the galla dinner of the 38th IAHR World congress, Panama
Figures 3-9 additional dedicated sessions were hosted in Granada (2022), and Vienna (2023) and Lisbon (2024)
Annual report
Activities
Upcoming activities:
IAHR Online Training Course on Modelling Software for Transient Flows
24-28 March 2025. Online (via Zoom)
This online training course is part of the new IAHR Training Courses Series and is organized by the IAHR Working Group on Transient Flows. It is designed for engineers, researchers, and professionals seeking to enhance their expertise in numerical modeling of transient flows in hydropower systems, water distribution networks, and industrial pipelines.
The course will provide a theoretical introduction to transient flow modeling, followed by practical applications using a variety of commercial and open-source software tools. Case studies will demonstrate the strengths, limitations, and applicability of different modeling approaches.
The speakers are: Anton Schleiss (EPFL, Switzerland), Bryan Karney (University of Toronto, Canada), Bruno Brunone (University of Perugia, Italy), Bryon Singh (University of Toronto, Canada), Christophe Nicolet (Power Vision Engineering, Switzerland), Enrique Cabrera (Polytechnic University of Valencia, Spain), Gerardo Riano (Cornell Tech, USA), Hanif Chaudhry (University of South Carolina, USA), Jose Adriasola (Bechtel Corporation, Chile), Kan Kan (Hohai University, China), Lina Sela (University of Texas, USA), Lu Xing (Xylem Inc, USA), Mohamed Ghidaoui (HKUST, Hong Kong), Nathan Gerdts (Autodesk, USA), Sam van der Zwan (Deltares, Netherlands), Shawn Huang (Autodesk, USA), Slavco Velicov (Bentley Systems, Netherlands), Trey Walters (AFT Impulse, USA), Yongguang Cheng (Wuhan University, China).
The coordinators are Silvia Meniconi (University of Perugia, Italy), David Ferras (Universidad Politécnica de Cartagena, Spain). The course is sponsored by: Deltares, Bentley, Power Vision Engineering (SIMSEN), and is supported by: China Society for Hydropower Engineering, and CSSI (Italy).
https://www.iahr.org/index/detail/1720
IAHR Monograph on transient flows
End of 2025
The IAHR Working Group on Transient Flows is developing a monograph titled "Transient Flows in Hydraulic Systems," coordinated by Silvia Meniconi (University of Perugia, Italy), David Ferras (IHE Delft, The Netherlands), Moez Louati (IHE Delft, The Netherlands), Dídia Covas (University of Lisbon, Portugal), and José Adriasola Velasco (Bechtel Corporation, Chile). This monograph aims to provide a comprehensive exploration of transient flow phenomena in hydraulic systems, combining theoretical insights, experimental findings, and practical engineering applications. It is designed for engineers, researchers, and professionals working in water supply networks, hydropower systems, and industrial fluid transport systems.
The key topics covered are: pressure surges and protection mechanisms, air-water interactions in pressurized systems, water hammer phenomena including frictional effects, line packing, and column separation, unsteady friction modeling and its role in damping pressure waves, fluid-structure interactions and their impact on system integrity, non-intrusive diagnostic methods for transient flow measurement, anomaly detection using pressure waves including leak and blockage detection.
The monograph is being authored by renowned experts in the field from leading institutions worldwide, including: António Betâmio de Almeida (CERIS, Instituto Superior Técnico, Universidade de Lisboa, Portugal), Steven J. Wright (Civil and Environmental Engineering, University of Michigan, USA), Bryan Karney (Department of Civil and Mineral Engineering, University of Toronto, Canada), Elias Tasca (Department of Water Resources, State University of Campinas, Brazil), Jim C. P. Liou (Department of Civil and Environmental Engineering, University of Idaho, USA), Giuseppe Pezzinga (Department of Civil Engineering and Architecture, University of Catania, Italy), David Ferras (Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft Institute for Water Education, The Netherlands), Arris Tijsseling (Department of Mathematics and Computer Science, Eindhoven University of Technology, Netherlands), Sandra Soares-Frazao (Institute of Mechanics, Materials and Civil Engineering, UCLouvain, Belgium), Bruno Brunone (Department of Civil and Environmental Engineering, University of Perugia, Italy), Silvia Meniconi (Department of Civil and Environmental Engineering, University of Perugia, Italy), Caterina Capponi (Department of Civil and Environmental Engineering, University of Perugia, Italy).
International IAHR Meeting on Transient Flows
25-26 November 2025. Carapina Pavilion, Greater Vitória Metropolitan Region, Brazil
The IAHR Working Group on Transient Flows and the Technical Committee on Hydraulics of the Brazilian Association of Water Resources (ABRHidro) are organizing the International IAHR Meeting on Transient Flows. This event was conceptualized during the 2023 IAHR World Congress in Vienna and is now set to take place alongside the XXVI Brazilian Symposium on Water Resources. The meeting will serve as a dedicated platform for researchers, practitioners, and industry experts to discuss cutting-edge developments in transient flow phenomena, modeling, and applications. By aligning with the Brazilian Symposium, the event aims to enhance international collaboration and increase engagement within the hydro-environment community. The scientific program will include keynote lectures, oral presentations, and panel discussions, covering a broad range of experimental, numerical, and applied studies related to transient flows in pressurized hydraulic systems.
The extended abstract submissions opened on March 1, 2025, and the submission deadline is June 9, 2025
https://eventos.abrhidro.org.br/xxvisbrh/iahr/message/
Past activities:
IAHR online short course: Perspectives on Two-phase Flows in Urban Water Systems, 8 to 10 May 2023
Establishing and chairing the sub-theme 3c on "Transient flows and pipeline hydraulics" , 39th IAHR World congress, 19-24 June 2022, Granada, Spain.
A session on Challenges in Transient Flows at the 1st IAHR online forum (July, 5th 2021 at 10am UTC) | Slides
IAHR Short Course on Transient Flows, November 2021, Online
Organizing the 1st special session on Transients in pipes, 37th IAHR World congress, KL-Malaysia, 13-18 August 2017.
Organizing the 2nd special session on Transients in pipes, 38th IAHR World congress, Panama city-Panama, 1 and 6 September 2019.
IAHR online short course: Perspectives on Two-phase Flows in Urban Water Systems, 8 to 10 May 2023
Online Panel Session on "Damping". The purpose of this Session would be to alert people to the many possible causes of so-called damping of pressure signals in transient flows in pipes and pipe networks
Resources and links
Contact
For any inquiry about the Working Group on Transient Flows, please send an email to TFWG.IAHR@gmail.com.