Environmental hydrodynamics

Duration

30h Th, 30h Pr

Number of credits

Lecturer

Benjamin Dewals

Language(s) of instruction

English language

Organisation and examination

Teaching in the second semester

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

Environmental hydrodynamics covers the study of water flow in rivers and the associated erosion and deposition processes.
The following topics are covered:

• Fundamental hydrodynamic principles applied to unsteady open channel flow (lesson n°1);
• Properties of the mathematical system, characteristic form, analytical solutions and an application to an idealized estuary (lesson n°2);
• Application to flow induced by the operation of gates in inlet or outlet channels, as well as to accidental floods (lessons n°3 and 4);
• Simplified models (kinematic and diffusive waves), application to the propagation of natural floods in rivers and discussion of the practical concept of rating curves (lesson n°5);
• Application to the operational management of a hydropower scheme (lesson n°6);
• Mechanisms of bedload and suspended load sediment transport, inception of sediment motion, design of stable channels (lesson n°7);
• Bedforms on alluvial riverbeds (ripples, dunes, antidunes), consequences on flow resistance, navigation and flood risk (lesson n°8);
• Quantitative modelling of erosion and deposition, ad hoc numerical schemes, techniques for accelerating the computation (lesson n°9);
• Impact of constructions on the stability of river beds (erosion / aggradation) and mitigation measures (lesson n°10);
• Real-world engineering applications: reservoir sedimentation, river restoration and bed stability assessment (lesson n°11);
• Local scour (bridge piers and abutments, sills, pipelines ...) and countermeasures (lesson n°12);
• Preparation for the exam (lesson n°13).

Learning outcomes of the learning unit

The aim of the course is to give the students insights into the mechanics and physics which govern unsteady flow and sediment transport in natural rivers, and to provide a basis for predicting their response to natural or man-made disturbances.
These topics are of high relevance for solving practical problems, involving inherent complex phenomena, such as flood risk management, extending the lifetime of a dam, mitigating scour around bridge piers, assessing habitat for fish and other organisms ...
After this course, the student will be able to:

• model unsteady open channel flows in river networks or other hydraulic networks;
• understanding the physics underlying unsteady open channel flows (wave propagation, characteristic velocities);
• compute flows in simple real-world applications, based on the analysis of characteristics;
• understand and apply properly simplified flow models such as the kinematic, diffusive and dynamic wave approximations;
• assess the stability of sediments under given flow conditions and design stable channels;
• estimate the sediment transport rate in rivers (bedload and suspended load);
• assess erosion and sedimentation risks based on the flow characteristics;
• understanding the different degrees of complexity in turbulence modelling in open channel flows;
• estimate the scour depth in the near-field of hydraulic structures or obstacles (bridge piers and abutments, pipelines ...) and design countermeasures.

Prerequisite knowledge and skills

The lectures and considered applications rely on a fundamental understanding of numerical techniques (upwind schemes, stability criteria, prescription of boundary conditions ...).
Upon request, remediation classes may be planned with the teacher, specifically for Erasmus students.

Planned learning activities and teaching methods

The classes are divided in theoretical lectures and compulsory tutorial sessions.
All theoretical concepts taught during the lectures are illustrated by real-world applications and examples.
To enhance the involvement of students during the lectures, individual students are invited to present some developments in front of the group, with the support of the other students and under the guidance of the teacher.

Mode of delivery (face-to-face ; distance-learning)

The course consists in face-to-face classes divided in theoretical lectures and compulsory tutorial sessions. In the latter, the students are requested to submit an individual short report at the end of each session or a more comprehensive report after several sessions.

Recommended or required readings

Handouts areavailable on the e-learning platform eCampus.
To complement these handouts and help the student, lecture notes and references to chapters of textbooks, focusing on most topics addresses during the course, are also available on the e-learning platform eCampus.

Assessment methods and criteria

The students must take part in all tutorial sessions; otherwise they are not allowed to take the course exam.
All reports are marked individually.
An exam is organized during the June and September examination periods. It includes a theoretical part (oral) and a practical (written) part.
The theoretical exam is organized without any documentation available to the students, while the practical exam can be solved using the course material.
The final mark results from weighted average between the partial marks.
No partial exemption is granted.

Work placement(s)

Organizational remarks

Lectures take place during the second semester. The planning of the classes is given in section "Course contents" above. Slight changes may take place during the semester.
For the exercises and assignments, part of the work is conducted by the students during the tutorial sessions, during which a teaching assistant is available to answer questions of the students. Part of the work must also be performed by the student as homework assignments.
Most assignments are realized by groups of two students. The composition of the groups of students is imposed by the teaching assistant.
For a better chance of passing the exam, the students are strongly recommended to attend all classes.

Contacts

Prof. Benjamin Dewals
Hydraulics in Environmental and Civil Engineering (HECE)  
Département ArGEnCo
Quartier Polytech 1, Allée de la Découverte 9
Bâtiment B52/3, niveau +1, bureau +1/542
Tél. : 04/366.92.83
b.dewals@ulg.ac.be
The teacher is available to answer questions of the students. They are advised to set an appointment by email.
The teaching assistants involved in the tutorial sessions are also available to answer questions of the students.
An e-learning space is available on the platform eCampus. Among other features, it offers an online discussion forum which enables interactive exchanges in-between the students as well as with the teacher and the teaching assistants.