At the end of the module the student has acquired the fundamentals of heat transfer and he/she can solve complex heat transfer problems and to design, from the heat transfer viewpoint, mechanical elements and systems (for example: heat exchangers)
Course Prerequisites
The student will have to refer to the knowledge acquired with the courses of Fluidmechanics (Fluidodinamica) and Thermal Physics (Fisica Tecnica).
Teaching Methods
Teaching will take place mainly through lectures with a special attention to a direct interaction with students, which will have the possibility to propose deepening of some subject and to debate on them. Training sessions will be organised, with the aim to teach how to solve engineering problems in the field of applied thermofluid-dynamics (for the module Thermofluids) and engineering heat transfer (for the module Heat transfer) and to develop a critical skill on the subjects. The lecturer will prepare the subjects of each session on the basis of the topics developed during the lectures. Sessions on the use of specific software will be held.
Assessment Methods
The examination consists of two parts: the preparation of an end-of-course report on a subject previously approved by the course leader and an oral test. Both tests are compulsory. The report will have to be delivered some days before the oral test. During the oral test there will be a debate on the report content and its evaluation will be part (50%) of the final evaluation. The oral test is made by three parts: a discussion of the written report, a colloquium on a subject chosen by the candidate (different from that of the report) and a colloquium on different subjects to complete the survey. The result of the oral test (considerino the report evaluation) will yield the final mark. For those students enrolled for the Integrated Course on Thermofluids and Heat Transfer, the exams on the two modules can be taken separately, in such case the final mark will be the average of the two partial marks
Contents
Energy equations. Heat equations and external conditions. Adimensionalisation. Steady conduction: monodimensional problems. Integral approach. Electric analogy. Fins. Bidimensional problems: analytical methods, numerical methods. Unsteady conduction: method of lumped capacities and equivalent electrical circuits; analytical methods (separating variables, series, Duhamel's principle); Heisler diagrams. The problem of contact between two solids, effusivity. Periodical problems. Boiling heat transfer. Nukyiama diagram, critical flux, film boiling (analyitcal solution). Forced boiling: in ducts and external flows. Heat exchange in film and drop condensation. Radiation: basics. Spectrum and angle dependence. View factors, heat transfer among black and gray surfaces. Heat transfer with the sky, participating media. Heat transfer among surfaces with non-uniform radiosity. Heat exchangers: liquid-liquid, gas-gas, gas-liquid heat exchangers. Microexchangers. Heat exchangers for special applications.
Testo di riferimento: Fundamentals of heat and mass transfer, Incropera-De Witt, JW&Sons
Beside the textbook, slides from the lectures are made available. Iin case of authority provisions for the containment and management of epidemiological emergencies, teaching could undergo changes compared to what is stated in the syllabus to make the course and exams in in line with the provisions.
