222.586 Mixing and Transport Processes
This course is in all assigned curricula part of the STEOP.
This course is in at least 1 assigned curriculum part of the STEOP.

2023W, VO, 1.5h, 2.0EC


  • Semester hours: 1.5
  • Credits: 2.0
  • Type: VO Lecture
  • Format: Presence

Learning outcomes

After successful completion of the course, students are able to:

Part 1: Mixing processes

  • give examples of mixing and transport processes in the atmosphere, oceans, lakes, rivers in terms of specific physical quantities (solid/dissolved matter, heat/enthalpy, and momentum).
  • choose the mathematical framework with the appropriate level of complexity for modelling mixing and transport processes in a given configuration.
  • understand and explain the derivation of the mathematical formulations for mixing and transport processes.
  • explain and mathematically formulate the processes of advection, molecular and turbulent diffusion, and dispersion (longitudinal/transverse) of physical quantities.
  • define passive and (re)active physical quantities and consider them in computational models.
  • evaluate the relative importance of certain mixing and transport processes in a given configuration.
  • select adequate models/simplifications for specific problems in water bodies like lakes and rivers.
  • explain one-dimensional cross-section-averaged, two-dimensional depth-averaged and three-dimensional Reynolds-averaged models in terms of mixing and transport processes.
  • apply analytical solutions for problems using these models in simplified cases and to classify the application ranges and limits of these models (near/mid/far field).
  • quantify diffusion, dispersion as well as reaction coefficients.
  • determine/estimate the required/critical distance/duration for complete mixing across the cross-section of a stream with given geometric and hydraulic characteristics.
  • apply the Streeter-Phelps 1D model for water quality.
  • explain and apply the principle of discharge measurement by tracer/salt dilution method.
  • estimate the application limits of both analytical and numerical models as well as physical models and discuss their advantages and disadvantages.

Part 2: Sediment transport

  • discuss the field of application of the course material
  • discuss the semi-empirical nature of sediment transport theory
  • derive the control parameters of a problem based on dimensional analysis
  • estimate the settling velocity of sediment in water
  • explain the difference between bed load and suspended load sediment transport
  • quantify the threshold for the initiation of sediment transport as bed load and suspended load
  • design measures for the stabilization of a river bed
  • identify the main control parameters governing the transport of sediment
  • explain the modelling of the concentration of suspended sediment and the role of turbulence
  • quantify the rate of sediment transport as bed load, suspended load and/or total load
  • identify the most appropriate formula for quantifying the rate of sediment transport in a given configuration
  • discuss the uncertainty inherent in quantitative estimations of sediment transport
  • discuss the hypotheses underlying a sediment transport formula and its application range

Subject of course

1. Introduction : relevance, examples and summary of required pre-knowledge
2. Identification and mathematical description of mixing and transport processes
3. Simplified analytical solutions in laminar flow and 3D Reynolds-averaged models for mixing and transport processes in turbulent flow
4. 3D Reynolds-averaged models for mixing and transport processes in rivers
5. 1D Reynolds- and cross-sectional-averaged models for mixing and transport processes in rivers
6. Mixing and transport processes in the presence of chemical/biological processes
7. Engineering tools and project examples related to water-quality modelling
8. Sediment transport: modes of sediment transport, dimensional analysis
9. Sediment transport: initiation of motion and bedload transport
10. sediment transport : suspended load transport
11. Engineering tools and project examples

Teaching methods

A combination of plenary lecture and flipped classroom is used as follows:

  • Theory: Plenary lecture (for units with predominant theory) or flipped classroom (for units with predominant examples/exercises, first self-study followed by a plenary session)
  • Examples/exercises: flipped classroom (first self-study followed by a plenary session)

Note that it is important that the students understand the philosophy of the flipped-classroom concept. The fundamental assumption is that the lecturer-student interaction has more added value in the application of knowledge than in the acquisition of knowledge. Students acquire knowledge in an autonomous way through self-study. The forum and Sprechstunden are available for questions, discussion and feedback. The Plenary sessions focus on the application of the theory.

An important requisite for the successful implementation of the flipped-classroom concept is that students come well-prepared to the plenary session, i.e. they have thoroughly studied the theory and solved already some examples themselves.


Covid-19 format (if no present teaching should be possible):

Plenary lectures and plenary session are given online via Zoom. A complete transcription of the material is given in the notes of the corresponding ppt slides (TUWEL course - key: MTP22) .

Mode of examination


Additional information

All PowerPoint slides including the transcriptions are available on TUWEL (key MTP22). These Powerpoint slides are the only course material.

The exams are held in presence or online, depending on the currently valid requirements of the Ministry and the Rectorate. If the examinations have to be held online, the use of the same material as for the presence examination is permitted. If you are unable to attend a presence examination for good reason, as well as if you have any further questions, please contact the responsible assistant when registering for the examination (at least 7 days in advance).



Course dates

Thu14:00 - 16:0005.10.2023 - 25.01.2024EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Mixing and Transport Processes - Single appointments
Thu05.10.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu12.10.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu19.10.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu09.11.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu16.11.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu23.11.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu30.11.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu07.12.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu14.12.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu21.12.202314:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu11.01.202414:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu18.01.202414:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes
Thu25.01.202414:00 - 16:00EI 10 Fritz Paschke HS - UIW Mixing and Transport Processes

Examination modalities

The exam will be in English and concerns the materials included in the PowerPoint documents, which are the only lecture notes.

The exam consists of 2 parts, separated by a 15 min break.

  1. 30 minutes theoretical questions: short multiple choice and open questions aiming at testing your understanding of the theory; there is no need to memorize or be able to derive equations. You are not allowed to use any lecture or personal notes, formularies, calculators, electronic devices, etc..
  2. 90 minutes practical calculation exercises: Electronic devices are not allowed, except a non-programmable pocket calculator (for example TI-30-Models, Casio fx-82/991 WITHOUT Plus). The only extra documentation allowed is the formulary, which includes all relevant information required to solve the exercises.

The theoretical part counts for half of the reachable points and the exercises count for the other half. Only the total amount of gained points will determine whether or not you pass the exam. There is no oral exam.


PRESENCE exams (expected from April 2022 on)

As before, the following applies to face-to-face examinations:

30 minutes theoretical questions:

A multiple-choice test is used for this, which is then evaluated automatically. A questionnaire and an answer sheet are issued. PLEASE NOTE: Only the correct ticks on the answer sheet will be evaluated! To prepare for the exam, it is essential to visit the tutorial in the TUWEL course. Extra tools, including lecture notes, formularies, pocket calculators, electronic devices, etc., are not permitted!

90 minutes practical calculation exercises:

PLEASE NOTE: Electronic devices are not permitted, with the exception of non-programmable pocket calculators. A formulary is issued during the examination (available for practice purposes on TUWEL).

Further information on the presence exam:

  • The available seats in the lecture hall are those where paper lies on the desk.
  • Do not forget to write your name and matriculation number on every page you use.
  • Put your Studentenausweis on the Table.
  • Beside your Studentenausweis, you are only allowed to have a pen and a Geodreieck on your desk for the theoretical part. For the exercises, you are allowed to have in addition a non-programmable pocket calculator and formulary (optional).
  • Questions can only be answered on official paper, i.e. the paper that you find on the desk. Additional paper can be obtained on request.
  • The theoretical questions must be crossed clearly on the answer sheet, not on the questionnaire (see tutorial in the TUWEL course).
  • Every exercise has to be answered on a separate page. The structure of your answers must follow and include the numbering of the questions.
  • All papers will be collected at the end, including drafts.


DayTimeDateRoomMode of examinationApplication timeApplication modeExam
Mon10:00 - 13:0007.10.2024HS 7 Schütte-Lihotzky - ARCH written06.09.2024 12:00 - 03.10.2024 12:00TISSPrüfung
Mon08:00 - 11:0016.12.2024HS 14A Günther Feuerstein written15.11.2024 12:00 - 12.12.2024 12:00TISSPrüfung
Thu09:00 - 12:0016.01.2025HS 17 Friedrich Hartmann - ARCH written16.12.2024 12:00 - 14.01.2025 12:00TISSPrüfung
Tue12:00 - 15:0004.03.2025HS 17 Friedrich Hartmann - ARCH written04.02.2025 12:00 - 28.02.2025 12:00TISSPrüfung
Wed14:00 - 17:0014.05.2025HS 7 Schütte-Lihotzky - ARCH written14.04.2025 12:00 - 12.05.2025 12:00TISSPrüfung
Tue10:00 - 13:0017.06.2025HS 8 Heinz Parkus - CEE written16.05.2025 12:00 - 13.06.2025 12:00TISSPrüfung

Course registration

Begin End Deregistration end
27.09.2023 12:00 26.01.2024 12:00 26.01.2024 12:00


Study CodeObligationSemesterPrecon.Info
033 266 Environmental Engineering Mandatory3. SemesterSTEOP
Course requires the completion of the introductory and orientation phase


No lecture notes are available.

Previous knowledge

The course (VO) Hydraulics (222.564) is highly recommended !

Preceding courses