OVERVIEW

Phenomena of mass, momentum and energy transport characterise a number of processes which are object of the research of chemical engineers. Many of these processes exploit turbulent-flow transport properties to increase the diffusion of reagents or they involve particle laden flows where chemical reactions take place on the particle surface.

The course provides the students with the fluid mechanics knowledge which is necessary to interpret and model the transport phenomena characterising industrial applications such as spray dryers, fluidised bed reactors, waste and drinking water plants.

A brief video-presenation of the course (4 min) is available at this link.

AIMS AND CONTENT

LEARNING OUTCOMES

The objective of the teaching is to provide the basic knowledge of fluid mechanics with a particular attention to mass transport processes. Examples of practical problems are formulated and solved during the lessons.

AIMS AND LEARNING OUTCOMES

During the course, the fundamental knowledge which is required to interpret, analyse and critically discuss a scientific article or a technical report or a chemical engineering project where mass, momentum and energy transport processes occur in a fluid, will be provided.

At the end of the course the student will be able to correctly formulate the problem of the fluid motion and the related transport phenomena both in the laminar and turbulent flow regimes. In addition, simple models will be illustrated that allow to solve the problem of the "closure of turbulence" even in the case of particle-laden flows.
The student will be finally able to choose the models, among those shown during the course, which are suitable to approach fluid dynamics problems that are relevant for chemical engineering applications.

PREREQUISITES

Basic knowledge of Physics, Calculus and Hydrodynamics.

TEACHING METHODS

Frontal lectures and Problem Based Learning (PBL).

Students with specific learning disorders (SLD, namely in Italian "disturbi specifici di apprendimento", DSA) will be allowed to use specific modalities and supports that will be determined on a case-by-case basis in agreement with the delegate of the Engineering courses in the Committee for the Inclusion of Students with Disabilities.

SYLLABUS/CONTENT

• Introduction to mass, momentum and energy transport phenomena

  • Mass, momentum and energy balance equations

  • Dynamics of a single particle in a fluid at rest or in motion

  • Dynamics of a couple or multiple submerged particles

• Diffusive processes in non-turbulent flow

  • Hints of particle Brownian motion

  • Fick’s laws

  • Oscillatory flow (second Stokes problem)

• Boundary layer theory (non-turbulent flow)

  • Mass transport around solid spheres and gas bubbles

• Thermal conduction in fluids

• Theory of developed turbulence

  • Turbulence phenomenology

  • Vorticity dynamics and energy cascade

  • Statistical tools for turbulence characterisation

  • Homogeneous and isotropic turbulence

  • Reynolds equations

  • Kinetic energy budget in a turbulent flow

  • Turbulent free shear and wall-bounded flows

  • Turbulence models

    • Boussinesq’s model of the deviatoric components of Reynolds stress tensor

    • Eddy viscosity and closure models: use of transport equations

  • Numerical simulation of turbulent flow (RANS, LES, DNS, other methods)

• Dispersion of solid particles in a turbulent flow

  • Fluid phase equations (averaging procedures)

  • Effects of particle-fluid interactions on the turbulence properties

  • Numerical models

    • Eulerian-Eulerian models

    • Eulerian-Lagrangian models (point-particle and particle-resolved approaches)

• Elements of dynamics of dense granular suspensions and flow in porous media

  • Darcy-Ritter law, Richards equation

• Examples of applications

  • Spray dryer

  • Fluidised bed reactors

  • Bio-fluid dynamics applications

RECOMMENDED READING/BIBLIOGRAPHY

Notes and slides of the course.

Suggested supplementary books:
- Fluid mechanics and Turbulence

• Kundu, Pijush K., Ira M. Cohen, and David R. Dowling. Fluid mechanics. Academic press, 2015
• Pope, Stephen B., and Stephen B. Pope. Turbulent flows. Cambridge university press, 2000
• Sinaiski, Emmanuil G., and Leonid I. Zaichik. Statistical Microhydrodynamics. John Wiley & Sons, 2008
• Monin, Andrei Sergeevich, and A. M. Yaglom. Statistical fluid mechanics, Volume I, 2007

- Transport phenomena and Multi-phase flows:

• Venerus, David C., and Hans Christian Öttinger. A modern course in transport phenomena. Cambridge University Press, 2018.
• Jakobsen, Hugo A.. Chemical Reactor Modeling - Multiphase Reactive Flows. Springer, 2008
• Crowe, Clayton T., et al. Multiphase Flows with Droplets and Particles. CRC Press, 2011

TEACHERS AND EXAM BOARD

Exam Board

MARCO MAZZUOLI (President)

RODOLFO REPETTO

PAOLO BLONDEAUX (President Substitute)

LESSONS

LESSONS START

https://corsi.unige.it/10376/p/studenti-orario

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

Oral examination.

The exams take place in the summer session (June, July and September) and in the winter session (January and February).

ASSESSMENT METHODS

The exam is aimed at verifying the capability of the student to formulate simple problems of fluid mechanics when the flow regime is turbulent.

The oral exam consists of two phases: in the preliminary phase a scientific article (selected in agreement with the professor) based on the themes of the course is analysed. This phase contributes to the 40% of the final evaluation. The remaining 60% is associated with the answers to two questions concenring the contents of the course.

Exam schedule