Technical Physics M - Z

The aim of the course is to provide a structured knowledge on:

- applied thermodynamics, with a main concern on its fundamental theoretical principles and, in particular, on its applications to the design, analysis and characterisation of the main components of energy plants, of the direct and inverse thermodynamical cycles and of air conditioning plants;

- the fundamental heat transfer mechanisms and their interactions, as well as the operative tools for the analytical description and characterisation of heat transfer in basic geometrical configurations and in heat exchangers.

Lectures and practical examples and exercises are presented in class with the help of didactical supports (slides, exercises, etc.) made available to the students on http://studium.unict.it at the begininning of and/or during the course. In the occurrence of pandemic conditions, on-line lectures will substitute classroom activities but in the respect of the declared course programme.

APPLIED THERMODYNAMICS

Thermodynamics and energy; heat transfer; the units of the IS; The thermodynamic system and the control volume; the state variables; the thermodynamic equilibrium. The zeroth law of thermodynamics. Gibbs’ rule or the equation of state; definitions of pressure, volume and temperature; thermodynamic processes and thermodynamic cycles; Energy: internal energy, kinetic and potential energy, the energy exchange at the boundary of the system: heat and work; Phase changes; diagrams and tables for saturated vapour; The ideal gas model and other state equations. Thermodynamic behaviour of real gas; The energy balance; specific heats at constant pressure and at constant volume; The thermodynamic analysis of the control volumes and steady flow processes, definitions of enthalpy and work exchanged in flows; The first law of thermodynamics for closed and open systems, the main devices operating in stationary flow condition; Definition of thermal engines and refrigeration systems; statements of the second law of thermodynamics. The direct and the inverse Carnot cycle; the Carnot theorems; the thermodynamic temperature scale; The concept of irreversibility; the definition of entropy; entropy diagrams; Gibbs equations and their applications to the case of ideal gas and of incompressible liquid and solid; the balance of entropy for open and closed systems; the isentropic efficiency; Energy and entropy balance for the analysis and characterisation of the basic components of technological plants; Direct gas and vapour Carnot cycles; direct gas cycles; the internally reversible Brayton-Joule cycle; the effect of irreversibilities; the regenerative Brayton-Joule cycle; basic concepts on other evolutions and on application in aeronautics; basic concepts on the Otto, Diesel and Sabathé cycles; The internally reversible Rankine cycle; the superheated Rankine cycle; technological and physical limits for vapour cycles; the effects of irreversibilities; regeneration, cogeneration and combined cycles; Inverse cycles for  refrigerators and heat pumps. Vapour compression cycles; the effect of irreversibilities; Mixtures of ideal and real gases, moist air; definition of thermodynamic variables and diagrams used in psychometrics, the main transformations and devices for the treatment of moist air.

HEAT TRANSFER

Introduction to heat transfer: the modes of heat transfer by conduction, convection and radiation. Temperature field and heat transfer; Fourier’s law of thermal conduction and the thermal conductivity  of materials; the steady-state conduction in homogeneous and isotropic materials; the electric-thermal analogy and the definition of conductive and convective thermal resistance; the evaluation of the stationary heat transfer for one-dimensional geometries: plane walls, cylinders and spheres; the critical radius of insulation; Heat transfer by external forced convection; dimensionless parameters of forced convection; the regimes of motion and flow on a flat plate; insight to other geometries; Heat transfer in bounded forced convection; the flow within ducts and channels; the heat exchange, the pressure drops and the Moody’s chart; Heat transfer in natural convection; Basic principles of radiation, black body and its fundamental laws, the radiative properties and the grey body model; Heat transfer by radiation; view factors; the heat exchange between black and gray surfaces; Heat exchangers; the overall coefficient of heat exchange; design criteria; the average logarithmic temperature difference; the e-NTU method; Mixed conduction and convection problems: finned surfaces and definitions of effectiveness and efficiency of a fin and of a finned surface; unsteady heat conduction; lumped parameter modelling and Heisler’s diagrams.

 1. Y.A. CENGEL - TERMODINAMICA E TRASMISSIONE DEL CALORE - MCGRAW-HILL​

2. M.J. MORAN, H.N. SHAPIRO, B.R. MUNSON, P.D. DE WITT - ELEMENTI DI FISICA TECNICA PER L'INGEGNERIA - MCGRAW-HILL

3. G. CESINI, G. LATINI, F. POLONARA, FISICA TECNICA, CITTÀ STUDI EDIZIONI

The exam consists of two parts: one written and one oral. The admission to the oral exam is achieved only through the assignment of a sufficient score (18/30) to the written test. Both written and oral exam aim to verify the student's ability to discuss and argue the theoretical aspects of the discipline and to solve practical and/or design problems. The written test consists of theoretical questions, formulated in such a way as to allow a synthetic analytical and/or graphical answer, and of practical problems requiring the calculation and/or the dimensioning of thermodynamic components and cycles, of heat exchange configurations and processes.

If the conditions for carrying out in presence didactic activities are guaranteed, students who achieve a classroom attendance of more than 70% will be offered two in itinere tests with optional participation. The first of the aforementioned tests will take place at the end of the applied thermodynamics lessons; the second will take place at the end of the course, at the end of the heat transmission lessons. Passing the two tests is equivalent to passing the written exam, provided that the oral exam is completed within the same academic year. Students attending online didactic activities will not be admitted to participation to in itinere tests.

To guarantee equal opportunities and in compliance with the laws in force, students enrolled in CInAP can agree with the teacher any compensatory and/or dispensative measures, based on the educational objectives and specific needs. It is also possible to contact the CInAP reference teacher of DIEEI (Prof. Arturo Pagano).

- State postulate
- Real gases: theoretical questions and analytical and/or graphical exercises
- Ideal gases: theoretical questions and analytical and/or graphical exercises through state diagrams
- Saturated mixtures: theoretical questions and analytical and/or graphical exercises through tables and state diagrams
- Incompressible liquid: theoretical questions and analytical exercises through tables

- Heat and Work: theoretical questions and analytical and/or graphic exercises that
- First Principle balances for closed and open systems: theoretical questions and analytical and/or graphical exercises
- Second Principle balances for closed and open systems: theoretical questions and analytical and/or graphical exercises
- Direct and inverse thermodynamic cycles, gas and steam: theoretical questions and analytical and/or graphical exercises
- Regenerative heat exchanges for performance optimization of thermodynamic cycles: theoretical questions and analytical and/or graphical exercises

- Psychrometry: theoretical questions and analytical and/or graphic exercises

- Stationary conduction in one-dimensional geometries: theoretical questions, analytical exercises, graphical schematizations
- External and internal forced convection and natural convection: theoretical questions, analytical exercises, graphical schemes
- Radiative behaviour of real bodies, the radiative models of the black body and of the grey body: theoretical questions, analytical exercises, graphical schemes
- Radiative thermal exchanges within cavities consisting of black bodies or grey bodies: theoretical questions, analytical exercises, graphical schemes

- Heat exchangers and calculation and sizing methodologies: theoretical questions, analytical exercises, graphical schemes