2022-2023 / GCIV2034-1

Free surface flow


27h Th, 25h Pr, 1d FW, 2h Labo., 10h Proj.

Number of credits

 Master of Science (MSc) in Civil Engineering5 crédits 


Sébastien Erpicum, Michel Pirotton

Language(s) of instruction

French language

Organisation and examination

Teaching in the first semester, review in January


Schedule online

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

This course is in the continuity of the lectures in Fluid Mechanics and Hydraulics given to the civil engineer students. From the Navier Stokes equations, it uses the free surface properties to set a single mathematical formalism applicable to continuous and discontinuous flows encounter on the rain drop trip which touches the ground surface and get to the see through the hydrographic network.
The course tackled in particular the notions of empirical and modern friction laws, critical and uniform water depths, shape and calculation of backwater curves, hydraulic head (critical head, conservation, dissipation), hydraulic jump and calculation of the flows over weirs and below gates, everything for man-made and natural cross sections. It also makes the link between free surface and under pressure flows, highlights the specificities of free surface flows and proposes a single approach to continuous and discontinuous flows.
It gives thus the whole of the elements useful to compute the flows over hydraulic structures and the related solicitations. In particular, all these theoretical elements lead to the physical understanding and the design of weirs.

Learning outcomes of the learning unit

At the end of the course, students will be able to adequately apply to free surface hydraulics the principles studied in the lectures of Fluid Mechanics and Hydraulics and to tackle in a single and critical way the notions of free surface hydrodynamics, avoiding the traditional separation between continuous and discontinuous flows.

In addition to the ex cathedra lectures giving the theory and the essential basic equations, these goals are met through guided practical reflection works, based on real cases, as well as through laboratory works. By writing reports, the students will develop their self learning skills as well as their ability to structure and summarize their work.

This course contributes to the learning outcomes I.1, I.2, III.1, III.2, IV.1, IV.2, IV.4, IV.5, V.2, VI.1, VI.2, VII.1, VII.2, VII.3 of the MSc in civil engineering.

Prerequisite knowledge and skills

Basic notions in fluid mechanics

Planned learning activities and teaching methods

The course lies on ex-cathedra lectures and obligatory and marked guided exercises. Some more important exercices and lab tests request the writing of individual or group reports.

Mode of delivery (face to face, distance learning, hybrid learning)

The course is made of sessions with a theoretical ex cathedra lecture and a practical part consisting in a guided exercise and the redaction of an individual report at the end of the session or after several thematic sessions.

Recommended or required readings

Slides of the lectures are available on e-Campus.

Assessment methods and criteria

Exam(s) in session

Any session

- In-person

written exam

Written work / report

Out-of-session test(s)

Additional information:

Handling in practical works reports is mandatory and leads to an individual mark.

A non exempting and mandatory examination is organized on the theoretical and practical matters related to the continuous flows.

A written examination is organized for the whole of the course during the January or September examination period. It counts for a theoretical and exercises parts. It is accessible solely to the students who provided all the practical works reports.

The theoretical examinations are organized without any support while the practical examinations can be solved using the course support.

The final mark results from a balance between the partial marks.

Work placement(s)

Organizational remarks

If needed and depending on the evolution of the sanitary constraints related to Covid, lectures will be given online through https://moodle.hece.uliege.be platfrom. 


Professeur Michel Pirotton and Sebastien Erpicum
Hydraulics in environmental and civil engineering (HECE)

Institut de Mécanique et de Génie Civil, Bât. B52/3
Quartier Polytech 1, Allée de la Découverte, 13
B-4000 Liège
Tél. : 04/366.95.36

email: Michel.Pirotton@uliege.be


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