31003 - Technical Physics and Systems T

Learning outcomes

The students will learn the principles of classical Thermodynamics and their extension to open systems. They will learn how to deal with simple thermodynamic systems. The students will be able to calculate the properties of atmospheric air, to work with its transformations and to apply them to HVAC systems.
The students will learn the basic mechanisms of Heat Transfer: conduction, convection and radiation. They will be able to deal with water vapour condensation in building structures at a basic level. Focusing on engineering applications, they will be able to handle in the correct way practical problems of heat transfer and energy conversion.

Course contents

THERMODYNAMICS

1.1 Introduction.
Introduction to Thermodynamics. System of units.
Principle zero of Thermodynamics. Thermometry.

1.2 First and second principle.
First principle of Thermodynamics for closed systems.
Second principle of Thermodynamics for closed systems:
statement by Kelvin-Planck, Clausius and their equiv ale nce.
The Carnot machine.
Irreversibility of natural phenomena.
Entropy and lost work. Thermodynamic temperature.

1.3 Open systems.
Mass balance for open systems.
Energy balance for open systems.
Practical examples.
Pressure drop. The chimney formula.

1.4 Pure substances, diagrams and cycles.
p-v-T surface for pure substances. The Gibbs rule.
Saturated vapours. Thermodynamic diagrams.
Rankine cycle. Basic refrigeration cycle. Heat pumps.

1.5 Air and vapour mixtures.
Description of air and vapour mixtures. Psychrometric transformations.
Basics of environmental control.
Measurement of relative humidity.

2. HEAT TRANSFER

2.1 Conduction.
Fourier law. Fourier equation.
Steady state solutions: plane layer, cylindric layer.
Critical radius.
Electric analogy and its limits.
Measurement of thermal conductivity.
Materials for the thermal insulation.

2.2 Convection.
Coefficient of convection.
Dimensional analysis and similarity.
Forced, natural and mixed convection.
Cooling by natural convection.
Dynamic and thermal boundary layer.

2.3 Radiation.
Basic definitions. Black and grey bodies.
Laws of Stefan-Boltzmann, Planck, Wien, Lambert, Kirchhoff.
Energy exchange between surfaces.
Solar radiation.

2.4 Combined heat transfer.
Global coefficient of heat transfer.
Heat exchangers.

2.5 Hygrometry
Water vapour balance in building stuctures.
Risk of condensation in building structures.
Glaser diagram.

3. APPLIED ACOUSTICS

3.1. Physical acoustics.
The nature of sound. Main acoustic quantities.
Sound speed in various media.
Plane, spherical, cylindrical, standing waves.

3.2. Psychoacoustics (introduction).
Human hearing system.
Annoyance and damage due to noise.

3.3. Sound levels, decibels and spectra.
Decibel scale.
(1/n) octave filters.
Frequency weighting curves.
Sound levels metrics.
Sound level meters.
Fourier analysis (introduction).

3.4. Building acoustics.
Sound insulation: basic laws.
Laws and standards.
Evaluation of the acoustic performance of buildings from the performance of their components.

3.5. Room acoustics.
Geometric approximation.
Statistic-energetic approximation. Reverberation.
Sabine and Norris-Eyring formulae for the reverberation time.
Wave approach (introduction).
Sound absorbing materials and systems.

4. Heating systems

5. Sanitary facilities

6. HVAC systems.

Readings/Bibliography

• Y. A. Çengel, G. dall'O, L. Sarto, Fisica tecnica ambiantale, McGraw-Hill, 1a Ed., Milano (2017).
• M. Spiga, Efficienza Energetica e Termofisica dell’Edificio, Esculapio, Bologna (2019).
• Y.A. Çengel, Termodinamica e trasmissione del calore, McGraw-Hill, 4a Ed., Milano (2009).
• E. Cirillo, F. Martellotta, Requisiti acustici passivi degli edifici, EdicomEdizioni, (2012)
• Y.A. Çengel, J.M. Cimbala, Meccanica dei fluidi, McGraw-Hill, 2a Ed., Milano (2011).
• S. Lazzari, B. Pulvirenti, E. Rossi di Schio, Esercizi risolti di termodinamica, moto dei fluidi e termocinetica, Esculapio, Bologna (2004).
• V. Corrado, E. Fabrizio, Applicazioni di termofisica dell'edificio e climatizzazione, Ed. CLUT, Torino (2005).
  A. Magrini, L. Magnani, La progettazione degli impianti di climatizzazione negli edifici, Ed. EPC Libri, Roma, 2a ed. (2010).
• R. Spagnolo (a cura di), Manuale di acustica applicata, De Agostini Scuola - Città Studi Edizioni, Torino (2008).
• G. Moncada lo Giudice, M. Coppi: Benessere termico e qualità dell'aria interna, Ed. Masson
• G. Moncada lo Giudice, S. Santoboni: Acustica, Ed. Masson
  G. Moncada lo Giudice, A. De Lieto Vollaro: Illuminotecnica, Ed. Masson
• G. Alfano, M. Filippi, E. Sacchi, Impianti di climatizzazione per l'edilizia, Ed. Masson
• N. Rossi, Manuale del termotecnico Hoepli
• AA.VV. Manuale di progettazione edilizia vol.2, Hoepli
  G. Moncada Lo Giudice, L. De Santoli, Progettazione di impianti tecnici, ed. Masson
• Dall'O', Palmizi, Impianti idrosanitari , Ed. CLUP

Teaching methods

During the lessons all the contents of the course will be treated. The lessons will be complemented by numerical exercises. A tutor will be available, outside lesson hours, for explanations and exercises.

Assessment methods

The final exam consists of a written test and an oral part, dealing with the notions presented during the course. The written session usually consists of 8 questions, 6theoretical questions and 2 numerical ones. In order to be eligible to take the oral exam, the student must score in the written test a minimum total of 18/30 points. The oral session consists of a technical conversation aimed at evaluating the organic understanding of the subject with reference to the key concepts illustrated during the course.

Higher grades will be awarded to students who demonstrate an organic understanding of the subject, a high ability for critical application, and a clear and concise presentation of the contents.
To obtain a passing grade, students are required to at least demonstrate a knowledge of the key concepts of the subject, some ability for critical application, and a comprehensible use of technical language.
A failing grade will be awarded if the student shows knowledge gaps in key-concepts of the subject, inappropriate use of language, and/or logic failures in the analysis of the subject.

Teaching tools

PC projector and materials downloadable from teacher’s web site.

Office hours

See the website of Luca Barbaresi