Transport phenomena

Duration

30h Th, 20h Pr

Number of credits

Lecturer

Andreas Pfennig

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

This course presents an analysis of the transport phenomena at the basis of chemical engineering with the focus on heat and mass transfer.

• Definitions of extensive and intensive properties. Concepts of mass, momentum, and energy balance equations. Dimensionless numbers, Pi-theorem.
• Molecular basis for heat and mass transfer. Similarity between both.
• Energy-balance equation. Conductive and radiative contributions. Fourier's law: thermal conductivity. Stefan-Boltzmann's law: Stefan-Boltzmann constant, emissivity. Conductive stationary heat transfer: heat-transfer coefficient. Conductive transient heat transfer: Fourier's number.
• Mass balances. Absolute and relative flux, diffusional flux. Fick's and Maxwell-Stefan law, different molecular diffusion coefficients. Transient mass transfer. Quasi-stationary mass transfer: mass-transfer coefficient.
• Convective heat and mass transfer. Stagnant-film model, surface-renewal theory, penetration theory, two-film theory. Dimensionless numbers. Correlations of mass-transfer coefficients.
• Instabilities at interfaces induced by mass transfer.

Learning outcomes of the learning unit

At the end of the course, students will be able to apply theoretical concepts and the analysis methodology of transport phenomena, especially heat and mass transfer. They will use these concepts to describe mathematically simple experimental systems. They will be able to use the formalism of mass and heat-transfer coefficient.
Students will be able to link investigated phenomena to their mathematical representation and justify main simplifications adopted to develop the model
Exercise and laboratory sessions in small groups will help the students to develop more transverse skills as team-working, solving numerical problems, critical analysis of experimental data, assessment of the validity of a theoretical approach and report writing.

Prerequisite knowledge and skills

The courses "Eléments de thermodynamique" CHIM0286-1, "Chemistry" (CHIM0603-1), and "Elements of fluid mechanics" (MECA0011-2) (or courses with similar contents) should have been attended during previous years (or they should be attended the same year).

Planned learning activities and teaching methods

The course is based on ex-cathedra lectures (30 h) and practical courses (20 h) including exercises and laboratory sessions.
The ex-cathedra lectures are dedicated to the detailed description of the fundamental concepts necessary for the analysis and mathematical representation of transport phenomena.
Practical courses include exercise sessions during which students learn how to solve problems related to heat and mass-transport phenomena.
During laboratory sessions, students work in small teams. They have the opportunity to get familiar with experimental measurement techniques of transport properties in fluid phases.
Participation to laboratory sessions is mandatory. The sessions have to be prepared by carefully reading the corresponding laboratory notes, which will be checked by an entrance test. If the entrance test is not passed, access to the laboratory sessions may be denied. A report should be realized (maximum 2 weeks) after the lab.

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

face-to-face

Recommended or required readings

The course material is available on the eCampus website. Additional information (exercises and laboratory notes) will also be made available on the eCampus website during the course.

Assessment methods and criteria

Participation to lab and the report are mandatory to pass the exam.
A written exam is organized during the first session in June.
The written exam consists of exercise problems to be solved, which are similar to those presented during exercise sessions. The remaining about 40% consist of questions referring to basic understanding of the lecture content.
It is a closed-book exam. Students receive a formulary with all relevant equations for solving the problems together with the exam problems.
Moreover, a report of the laboratory sessions must be provided by the students within 2 weeks after these sessions. This report must present the obtained experimental results, their critical analysis, as well as answers to the questions presented in the laboratory notes. The deadline for delivering the report will also be included explicitly in the lab instructions. If the report is not received by the deadline indicated, it is graded as 0 points.
The global mark is a weighted average of the marks obtained at the written exam (80 %) and the laboratory (including report and entrance test) (20 %).
The second session exam is organized identically. The mark obtained for the laboratory report is maintained.
Both exams may be oral, if the number of students is 5 or less.

Work placement(s)

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Organizational remarks

The course will be presented in English.
The course is organized during the second quadrimester.
The calendar of laboratory sessions will be communicated during the first lectures.

Contacts

Andreas Pfennig PEPs - Products, Environment, and Processes Department of Chemical Engineering University of Liège Quartier Agora, Allée du six Aout 11, Bâtiment B6c, office 1/66 phone: +32 4 366-3521 e-mail: andreas.pfennig@ulg.ac.be http://chemeng.ulg.ac.be/Pfennig