# 66707 - THERMOPHYSICS AND ACOUSTICS OF CONSTRUCTIONS T

## Academic Year 2021/2022

• Docente: Cesare Biserni
• Credits: 6
• SSD: ING-IND/11
• Language: Italian
• Teaching Mode: Traditional lectures
• Campus: Bologna
• Corso: First cycle degree programme (L) in Civil Engineering (cod. 8888)

## Learning outcomes

At the end of the course, after the final exam, the student is able to manage with the fundamental principles of thermodynamics, heat transfer and energetic analysis of systems, that will let him formulate the problems of energy efficiency in civil engineering, with particular care to energy saving in buildings. The student has also a basic knowledge on acoustics applied to noise control of transport facilities and in buildings.

## Course contents

Requirements/ Prior knowledge

The student attending this course has to manage with the basic mathematic tools. This knowledge is usually acquired by undergoing successfully the exam of Mathematical Analysis T. All lectures will be in Italian. Fluent spoken and written Italian is a necessary prerequisite in order to attend successfully the course and to manage with the lecture notes given by the teacher.

COURSE CONTENTS

1) APPLIED THERMODYNAMICS - AIR AND VAPOUR MIXTURES

The nature of thermodynamics: temperature and heat - Applications of thermodynamics to the closed system - The first law of the thermodynamics: work, internal energy and energy balances - The second law of thermodynamics and formulation of entropy - The open system: conservation of mass and balance of mechanic energy -The loss term and Moody Diagram - Macroscopic properties of pure substances: (p,v,T) surface and (p,v) diagram - Ideal gases and equation of state - (T,s) diagram - Air and vapour mixtures: psychrometric transformation and charts - Thermodynamic cycles: Rankine cycle and refrigeration cycle.

2) HEAT TRANSFER - BUILDING PHYSICS

Thermal conduction: Fourier's law - Fourier's equation - Simple cases of steady state conduction in cartesian and cylindrical coordinates - Thermal resistance and electrical analogy: thermal resistances networks - Steady state conduction with internal heat generation in cartesian and cylindrical coordinates - Thermal convection - The Newton's law - Heat transfer coefficient and Nusselt number - Dimensionless equations, Buckingam Theorem and relationships Nu = Nu (Re, Gr, Pr) - Critical insulation radius – Extended surfaces (fins) - Radiation heat transfer- Global heat transfer coefficient: thermal transmittance with reference to the building envelope.

3) APPLIED ACOUSTICS

The nature of sounds: preliminary notions and main acoustic quantities - Decibel sound levels and spectra - Decibel scale -Sound levels metrics- Room acoustics: sound absorption and reverberation time- Sound insulation: mass law and coincidence effect.

## Readings/Bibliography

The handwritten notes taken during the lessons and the material given by the teacher are enough to prepare for the exam. In order to achieve a deeper knowledge of some topics or for self-study, the following books are suggested:

- Y.A. Cengel, Termodinamica e trasmissione del calore - Quarta edizione, McGraw-Hill;

- G. Cammarata, Fisica Tecnica Ambientale, McGraw-Hill;

-Y.A. Çengel,G. dall’O’, L. Sarto, Fisica Tecnica Ambientale, McGraw-Hill;

- A. Cocchi, Elementi di Termofisica generale e applicata, Progetto Leonardo;

- R. Spagnolo, Manuale di Acustica Applicata, UTET;

- E. Cirillo, Acustica Applicata, McGraw-Hill;

- M. Spiga, Efficienza Energetica e Termofisica dell’Edificio, Esculapio.

## Teaching methods

Classroom lessons and guided solution of 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 5 questions, 3 theoretical 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.

In case restrictive conditions due to COVID persist, the test will be oral in the Teams platform, with theoretical questions and numerical exercises.

## Teaching tools

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

## Office hours

See the website of Cesare Biserni

### SDGs

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.