Understand: (i) The connections between the processes of the material systems and the energy exchanges. (ii) The fundamentals of elementary thermodynamics based on the first and the second law. (iii) How the theory of applied thermodynamics can be used to study energy conversions in power, propulsion and industrial processes. (iv) The fundamentals of the transfer of mechanical and thermal energy and radiation in solid and fluid systems applied to real systems, as heat exchangers.

The aim of the course is to provide students with the tools to analyze simplified systems from a thermodynamic point of view. At the end of the course, students should be able to apply the first and second principles of thermodynamics to both closed and open systems. Furthermore, the students should acquire the ability to calculate energy transfers and efficiency for the main gas and steam systems. Finally, the student should be able to recognize the different modes of heat transfer and then evaluate the system-environment heat exchange, both at steady state and in transient conditions.

Calculus. Linear algebra. Fundamentals of Differential Equations. Fundamentals of Physics I and II.

The course is subdivided in two parts the first about Thermodynamics (about 2/3 of the course) and the second about Heat Transfer (about 1/3 of the course). LECTURES TOPICS Thermodynamics: Introduction to thermodynamics: (8 h) Definitions. Energy in a thermal system. Work and heat in thermodynamics. Actual and ideal processes. The first law of thermodynamics for closed and open systems. Thermodynamic cycles, efficiency. Simple compressible systems: (6 h) Water: 3D surface, single phase and two phases regions. Phase changes at constant pressure. Water tables. The ideal gas: state equations and properties. Internal energy and enthalpy. Ideal gas characteristic processes: closed and open systems The second law of thermodynamics for closed and open systems: (4 h) Clausius and Kelvin-Planck statements. Main kinds of irreversibility. 1st and 2nd Carnot corollaries. Thermal efficiency and coefficients of performance. The Carnot ideal power cycle. Clausius inequality and entropy changes. The Gibb’s equations. Second law of thermodynamics: closed and open systems. Isentropic efficiency: turbines and compressors. Work in an open system Vapour power and refrigeration cycles: (4.5 h) The ideal Rankine cycle. Actual vapour cycles: irreversibility and losses. Superheated and reheated vapour cycles. Regenerative vapour power cycles. Refrigeration vapour cycles: the p,h diagram. Gas power and refrigeration cycles: (4.5 h) Internal combustion engines: Otto and Diesel cycles. The ideal and actual Joule cycle. Regenerative Joule cycle. Gas refrigeration cycles Psychrometry and air conditioning: (6 h) Moist air properties. Psychrometric charts. Moist air processes. Air conditioning: sensible and latent loads. Air conditioning processes in winter and summer season Heat Transfer Conduction heat transfer: (7.5 h) Fourier’s law. Heat transfer equation. Boundary and initial conditions. Heat transfer by conduction at steady state: Cartesian and cylindrical coordinates. The electrical analogy. 1D conduction heat transfer with and without volumetric energy generation. Transient conduction: the lumped capacitance method. Finned surfaces. Convection heat transfer and heat exchangers: (7.5 h) Newton’s law. Boundary layer phenomena. Free and forced convection. Methods for estimating the convection coefficients. Heat exchangers simple configurations: parallel flow and counter flow heat exchangers. Rate of heat transfer and the mean log temperature difference method. The e-NTU method. Heat transfer by radiation: (5 h) Spectral and total quantities: emissive power, irradiation and radiosity. Black body properties: Planck’s distribution, Stefan Boltzmann’s law. Gray bodies properties. The electrical analogy: space and surface resistances. Rate of heat transfer for both black and gray bodies.

The course is organized in theoretical and applied lectures( to learn to solve exercises that apply the subjects dealt with in lessons) and laboratory experiments. Exercises will be proposed to learn to solve problems that apply the subjects dealt with in lessons (about 27 h). Some of them will be solved during the class while the remainder may be solved as homework (solutions are anyway provided).

M. W. Zemansky, M.M. Abbott, H.C. Van Ness, "Basic engineering thermodynamics", Mc Graw Hill M.J. Moran, H.N. Shapiro, 'Fundamentals of engineering Thermodynamics', J. Wiley & Sons, Inc., 2006. P.S. Schmidt, O.A. Ezekoye, J.R. Howell, D.K. Baker, 'Thermodynamics: An Integrated Learning System', J. Wiley & Sons, Inc., 2006. F.P. Incropera, D.P. De Witt, 'Fundamentals of Heat and Mass Transfer', J. Wiley & Sons, Inc Y. A. Çengel, 'Introduction to thermodynamics and heat transfer", 2nd Edition, McGraw-Hill, 2008. M.J. Moran, H.N. Shapiro, B.R. Munson, D.P. DeWitt, 'Introduction to Thermal Systems Engineering, Thermodynamics, Fluid Mechanics and Heat Transfer', J. Wiley & Sons, Inc., 2003.

Modalità di esame: Prova scritta (in aula);

Exam: Written test;

... The exam consists of two parts: a written test (4 exercises, 2 about thermodynamics and 2 about heat transfer to be solved in 2 hours) and an oral. To take the written test is compulsory to be booked and the students cannot carry with them any kind of material (books, lecture and tutorial notes, formula cheat sheets, etc.). The minimum mark to pass the written test and to be admitted to take the oral is 18/30 (the maximum is 30/30). The oral is compulsory only for students with a written test grade higher than 25/30. It’s up to the students with a lower mark to decide whether to take the oral or simply accept or reject the written test mark. On the basis of the learning outcomes expected, during the oral exam the achievement of the following skill sis verified: 1) the ability to describe and analyze the main devices for energy production from a thermodynamic point of view, evaluating the mechanical and thermal energy exchanged. 2) the ability to calculate, in a simplified way and for different systems, the energy exchanged by conduction, convection and radiation. The final grade is approximately the average between the written test and oral marks. While students can withdraw their written test they cannot reject the final mark.

Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.