Committee on Fluid Mechanics
#iahrFluidMechanics
Next events
10th Gerhard-Jirka Summer School Environmental Fluid Mechanics, Lima, Peru, from August 11th to August 15th, 2025. Organiser: Dr Daniel Horna-Munoz
Mission statement
The focus of our committee is on fundamental and applied environmental fluid mechanics in support of hydraulic research. Particular emphasis is on the fundamentals of transport and mixing phenomena in turbulent flows such as contaminant transport processes in rivers, lakes and coastal regions, anthropogenic influences (e.g., heat, dissolved and suspended organic/inorganic material) and sediment dynamics. Main focus areas for our committee include:
stratified flows (e.g., gravity currents, stratified jets and plumes, internal waves) and flows in rotating fluids, where at larger scales the rotation of the earth becomes relevant;
shallow flows, in which the length scale in one direction (depth) is much smaller than the length scales in the other directions, and for which bed friction affects the development of the large-scale quasi two-dimensional structures;
flow and turbulence structure over rough boundaries and porous media, including canopies and vegetation.
two-phase laminar and turbulent flows with particular emphasis on sediment transport, high concentration mixtures showing non-Newtonian fluid behavior (e.g., mud slides, debris flows) and gas-water mixture flows caused by air entrainment at high-velocity in hydraulic structures or by cavitating flows.
interface problems. The air-water interface on the surface of a water body remains enigmatic, especially concerning the generation, growth, and instabilities of wind waves. Similarly, the water-sediment interface at a stream bed separating turbulent water flow from the behavior of granular media has not been successfully described. Solid-water interfaces encountered in biological applications (e.g. boundary layers on individual blades of vegetation or coral branches) present another unique challenge.
Major advances are expected over the next couple of years in gaining insights into the dynamics of these flows using state of the art experimental (e.g., particle image velocimetry) and numerical (e.g., direct numerical simulation DNS, large eddy simulation LES, large-scale predictive models) techniques. In particular, this should allow a better understanding of the role played by the large-scale coherent structures and the interactions between these large scales and the three-dimensional turbulence, and of the effect of the large-scale turbulence on bottom friction and morphodynamic processes.
Three of the most important and imminent challenges in environmental fluid mechanics and environmental hydraulics are to understand:
to what extent the physics of these flows is dependent on scale effects,
how the physics changes between the simpler geometries studied in the laboratory in controlled environments or using DNS/LES simulations and the complex geometries present at field scale,
how detailed understanding of the physics of simpler types of flows (e.g., jets, wakes, mixing layers) can result into better predictive analytical models that can be applied for engineering predictions and design.
These challenges also define our long term objectives. Additionally, several challenges remain related to understanding mass exchange processes relevant to hydraulics. For example, concepts such as large-scale eddy diffusivity or hydrodynamic dispersion cannot be rigorously related to the actual flow or solid matrix properties. Empiricism prevails. Advances are urgently needed to provide the tools for the solution of modern hydraulic engineering problems - which are increasingly devoted to the prediction of the transport and deposition of materials in the natural or engineered environment. Double-diffusion is another phenomenon which has not gained needed attention.
Annual report
Past events and publications
IAHR Gerhard Jirka Summer School on Environmental Fluid Mechanics
The School is a signature IAHR event that was founded and energised by the late Professor Gerhard Jirka, with a vision to bring together renowned experts and top graduate students from around the world for a unique, interactive learning experience in environmental fluid mechanics. A central objective of the School has always been to combine theory, experiments and applications, with an emphasis on basic theoretical principles (and their mathematical description) as well as consideration of examples of engineering design and environmental applications. This objective is realised in the School through formal, in-class lectures as well as informal, out-of class excursions and visits. In the School, the students have plenty of opportunities to present their own research projects and to discuss and seek advice on these projects from Lecturers and fellow students.
The school was previously held in:
9th Gerhard-Jirka Summer School Environmental Fluid Mechanics, 28 August - 1 September 2023 | Dresden, Germany | Report
2018 | Mato Grosso do Sul (UFMS), Campo Grande, Brazil
2014 | Hong Kong SAR, China
2012 | Lucerne, Switzerland
2009 | Santiago, Chile
2006 | Karlsruhe, Germany
2004 | Budapest, Hungary
2001 | Dundee, Scotland
1998 | Karlsruhe, Germany
International Symposium on Environmental Hydraulics (ISEH)
10th International Symposium on Environmental Hydraulics (ISEH 2024). 25-27 June 2024 | Aberdeen University, United Kingdo
9th Symposium on Environmental Hydraulics (ISEH 2021). July 18-22, 2021 | Seoul National University, Seoul, Korea | Chair: I.W. Seo
8th International Symposium on Environmental Hydraulics (ISEH 2018). 4-7 June 2018 | University of Notre Dame, Indiana, USA https://ceees.nd.edu/iseh2018
7th International Symposium on Environmental Hydraulics (ISEH 2014). 7-9 January 2014 | Singapore
6th International Symposium on Environmental Hydraulics (ISEH 2010). 25-26 June 2010 | Athens, Greece
5th International Symposium on Environmental Hydraulics (ISEH 2007). 4-7 December 2007 | Arizona State University, Tempe, AZ, USA
4th International Symposium on Environmental Hydraulics (ISEH 2004) and 14th Congress of the IAHR Asia and Pacific Division. 15-18 December 2004 | Hong Kong SAR, China
3rd International Symposium on Environmental Hydraulics (ISEH 2001) with a Special Theme on Urban Fluid Dynamics. 5-8 December 2001 | Tempe, Arizona, USA. Contact: don.boyer@asu.edu
2nd International Symposium on Environmental Hydraulics (ISEH 1998). 16-18 December 1998 | Hong Kong SAR, China
1st International Symposium on Environment Hydraulics (ISEH 1991). 1991 | Hong Kong SAR, China
International Symposium on Stratified Flows (ISSF)
9th International Symposium on Stratified Flows. 29 August-1 September 2022 | University of Cambridge, UK | Chair: Colm-cille Caulfield
7th International Symposium on Stratified Flows. Rome, Italy, 2011. Chair: Antonio Cenedese
6th International Symposium on Stratified Flows. The University of Western Australia, Perth, 11-14 December 2006 (abstracts and CD-ROM)
5th International Symposium on Stratified Flows. Vancouver, Canada, July 10-13, 2000.
4th International Symposium on Stratified Flows. Grenoble, France, 1994.
3rd International Symposium on Stratified Flows. Pasadena, USA, 1987
2nd International Symposium on Stratified Flows. Trondheim, Norway, 1980
1st International Symposium on Stratified Flows. Novosibirsk, 1972
International Symposium on Shallow Flows (ISSF)
5th International Symposium on Shallow Flows 23-25 October 2021 | Co-organized by Hohai University, Nanjing Hydraulic Research Institute, Yangtze Institute for Conservation and Development, and State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, in Nanjing, China | Playback Video
4th International Symposium on Shallow Flows. 26-28 June 2017 | Eindhoven, The Netherlands
3rd International Symposium on Shallow Flows. 4-6 June 2012 | Iowa, USA Announcement Report
2nd International Symposium on Shallow Flows. Hong Kong
1st International Symposium on Shallow Flows. 16-18 June 2003 | Delft, The Netherlands. Proceedings
Other
Short course on Winter School on Numerical Methods Part I: Hyperbolic Equations and Applications. 2-13 February 2015 | Trento, Italy
Short course on Advanced numerical methods for free surface hydrodynamics. 19-30 January 2015 | Trento, Italy
2nd Fluids in New Zealand Workshop (FiNZ 2014). 29-31 January 2014 | Auckland, Australia
2nd Interntional Conference on Waste Water Discharges. 16-20 September 2002 | Istanbul, Turkey
Meeting Minutes
IAHR Committee on Fluid Mechanics Meeting Minutes. 19 June 2022