Transport Phenomena II
Objectives
Understanding of mass transfer fundamentals. Mathematical formulation of mass transfer problems for different geometries.Evaluation of diffusion coefficients and mass transfer coefficients.
General characterization
Code
10678
Credits
6.0
Responsible teacher
Isabel Maria Rola Coelhoso, Pedro Miguel Calado Simões
Hours
Weekly - 4
Total - 70
Teaching language
Português
Prerequisites
n/a
Bibliography
Cussler, E.L., " Diffusion: mass transfer in fluid systems", 3rd ed., Cambridge University Press, UK, 2009.
Bird, R.B.; Stewart, W.E.; Lightfoot, E. N. Transport Phenomena. 2nd ed. J Wiley & Sons, 2007.
Welty, J.R; Wicks, C.E.; Wilson, R.E.; Rorrer G.L. Fundamentals of momentum, heat and mass transfer. 5th ed. John Wiley &Sons, Inc, N.Y., 2010.
Teaching method
The teaching comprises lectures and solving problems sessions which cover all the contents according to the syllabus. Example problems are solved to illustrate the given concepts.
Evaluation method
The continuous assessment of the discipline is carried out through 2 tests, each worthing 35% of the final grade and exercises mandatory in the class in groups worth 30% of the final grade.
The exercises are 3: 1st- chapter 1- 5%, 2nd- chapter 4- 10% and 3rd- chapter 5- 15%.
The first test covers the material in chapters 2 and 3 of the course syllabus. The second test covers the material given in chapters 6 and 7.
The duration of the tests is 1h. Each test is evaluated from 0 to 20 values. The assessment is individual and without consultation. A minimum classification of 10 (9.5) values is required, on a scale from 0 to 20, in the average of the test scores and in the average of the scores of the exercises.
If the student does not pass the tests or chooses not to do so, he/she will be entitled to an appeal exam. A minimum classification of 10 (9.5) values, on a scale from 0 to 20, is required in the exam grade and exercises for approval in the discipline. The final grade will be 70% of the mark on the exam and 30% of the grade for the exercises.
Subject matter
- Fundamentals of mass transfer. Definitions of concentrations, velocity and flux; Fick’s first law. Nernst-Planck equation. Diffusion coefficients; Methods for estimating diffusion coefficients. Diffusion of ionic species. Multicomponent diffusion.
- Differential equations of mass transfer. Boundary conditions. Steady state molecular diffusion; Diffusion through a stagnant film; Equimolal counterdiffusion;
- Diffusion with heterogeneous chemical reaction. Pseudo steady state diffusion.
- Unsteady state molecular diffusion. Stefan-Maxwell equations. Analytical solutions of Fick’s secondlaw.
- Convective mass transfer; Dimensional Analysis; Concentration boundary layer; Models and analogies of Reynolds and Chilton-Colburn; Empirical correlations.
- Interphase mass transfer; Equilibrium gas- liquid and liquid- liquid; Two-resistance theory; Overall and individual mass transfer coefficients.
- Diffusion with homogeneous chemical reaction; Hatta number; First and second order reactions.