Heat Transfer
Code
10505
Academic unit
Faculdade de Ciências e Tecnologia
Department
Departamento de Engenharia Mecânica e Industrial
Credits
6.0
Teacher in charge
João José Lopes de Carvalho, José Fernando de Almeida Dias
Weekly hours
5
Total hours
98
Teaching language
Português
Objectives
Learn new concepts and become familiar with the analytical techniques in the three domains of heat transfer: conduction, convection and radiation.
Acquire skills to formulate and solve common problems concerning heat transfer in various engineer situations such as insulation and heat exchange.
Learn to manage the limited time available at all moments of evaluation.
Prerequisites
It is assumed the knowledge of the matters dealt with in: «Física II», «Análises Matemáticas», «Dinâmica dos Fluidos» I and II.
The written evaluations have implicit that the student is able to express his/hers train of thought intelligibly, either in portuguese or english, and to apply the mathematical tools that are used in the course.
Subject matter
1- Heat transfer modes: Fourier, Newton and Stefan-Boltzmann laws. Heat diffusion equation. Thermal diffusivity. Isotherms and heat flux. Electrical analogy.
2- Uni and multi-dimensional steady-state conduction: mathematical and numerical methods (finite differences).
3- Dynamic conduction: Biot and Fourier numbers. The Heisler charts. Periodic regime.
4- Forced convection: differential energy conservation equation in the thermal boundary layer. Prandtl and Nusselt numbers. Turbulent regime. Empirical correlations.
5- Heat exchangers: thermal design by the LMTD and effectiveness methods.
6- Natural convection: in a laminar boundary layer. Grashof number. Local and mean Nusselt numbers. Empirical correlations for turbulent regime.
7- Radiation: properties. The black body. Kirchhoff law. Wien''''s displacement law. Gray bodies. Monochromatic and total emissivities. Shape factors. Fundamentals of environmental radiation.
Bibliography
1. Holman, J. P., Heat Transfer. 10th Edition. McGraw-Hill Book Co, USA, 2010
2. Çengel, Yunus A., Heat and Mass Transfer: A Practical Approach. 3th Edition. McGraw‑Hill, 2006
3. Incropera and Witt, Fundamentals of Heat and Mass Transfer, John Wiley & Sons, 7th Edition, 2011
4. Bejan, Adrian, Heat Transfer, John Wiley & Sons, 4th Edition, 2013
Teaching method
The presentation of the subjects, using the board and audiovisual media, is made either in classes designated as theoretical (2h) or practices (3h), progressing the matter in a continuous method. That is, immediately after presentation, practical problems are presented by the teacher and solved by the students, with the help of teacher, which aims to consolidate the newly taught concepts.
Evaluation method
The assessment is continuous with theoretical-practical component consisting of three short tests, weighing 100% to the final classification and with a minimum grade of 9,5 val.
The final grade is obtained from: NF=45% MT1 + 30% MT2 + 25% MT3. In the exam route, if EX < 9,5 then the student fails with NF=EX. The terms enter in this expression rounded to the first decimal place.
The short tests and exams are closed-book and the use of text-memory calculators is not allowed. Formulae found necessary will be given. Transgressions are subjected to what is foreseen in art. 9 of the RAC.