# APPLIED PHYSICS

OVERVIEW

The course aims to provide the basic knowledge necessary to understand the main applications of applied physics which are relevant for the design of small pleasure yacht. After the introduction to the laws of thermodynamics of energy systems the study of heat transfer and the main problems related to thermohygrometric comfort and environmental air conditioning are dealt with.

## AIMS AND CONTENT

LEARNING OUTCOMES

The aim of the course is the training of a person able to analyze and solve simple problems in different fields of applied physics, while helping to acquire a proper scientific-technical language.

AIMS AND LEARNING OUTCOMES

**Educational objectives**

Through the course contents, the student is able to analyze and solve simple problems in different fields of applied physics: applied thermodynamics, heat transfer, environmental comfort and air conditioning, with particular reference to applications relating to pleasure boats.

The lessons and activities are aimed simultaneously at

- encourage the acquisition of critical knowledge of the proposed themes or case studies and related physical phenomena,
- support the student in the acquisition of an adequate technical-scientific language, as an indispensable tool both for understanding technical documentation and for dialogue with the various players in the ship design and construction process.

**Learning outcomes**

At the end of the course students will have to

- remember the main thermophysical quantities/properties with the relative units of measure,
- be able to accurately identify the physical meaning of the terms that make up the mathematical expressions of the relationships/physical laws, with particular attention to dimensional analysis,
- be able to correctly interpret a proposed text, knowing how to discuss the proposed application or case study,
- be able to solve simple numerical problems,
- have a clear awareness of the physical phenomena treated and the related technical implications,
- have acquired an adequate technical-scientific language, which tends not to leave ambiguities in the interpretation.

In addition, as a desirable more advanced result, students will also acquire an awareness of the subject to be able to

- analyze more complex problems related to physical-applied applications in the nautical sector,
- study articulated design solutions relating to thermohygrometric comfort and air conditioning systems in pleasure boats.

PREREQUISITES

The following basic mathematical knowledge is necessary to effectively address the teaching content.

- Calculation of areas and volumes of simple geometries.
- Functions: line, module, parabola, hyperbola, logarithm, exponential, trigonometric functions (sine, cosine, tangent and related inverse functions).
- Resolution of equations and of first and second degree, of equations with logarithms and trigonometric functions.
- Simple inequalities.

For a critical understanding of the physical phenomena treated, it is also desirable to master the following contents of the mathematical analysis.

- Concept of limit.
- Differential calculus of a real variable: geometric interpretation of the concept of derivative and integral, calculation of derivatives and primitives of simple functions.
- Ordinary differential equations to the separable variables of the first and second order.

In order to face the resolution of simple numerical problems, the student must be able to use a scientific calculator.

Teaching methods

The course is in Italian according to the TBL teaching method. The Team Based Learning is a teaching strategy based on independent study and collaborative learning.

The method involves the following steps. Before each lesson, the didactic contents for the independent study are assigned. On the same contents, individual and group activities are then carried out in the classroom to apply and verify the knowledge acquired: generally both multiple choice test with immediate feedback, to be solved individually or in groups, and practical problems to be analyzed and numerically solved, are also administered. These activities are intended to encourage learning through team discussion. The teacher stimulates and moderates the discussion, resuming and specifying, even with subsequent lectures, the different contents according to the critical issues that emerged.

For group activities the class is divided into teams defined by the teacher and stable for the duration of the course.

All individual and group activities are subject to evaluation.

The student's adhesion to the TBL is consequent to the acceptance of the "classroom agreement" at the beginning of the course and provides for compulsory attendance.

If a student does not join the TBL, he is exempt from the obligation to attend, can take advantage of the teaching material made available and can attend the frontal lessons, but does not participate in classroom activities and is evaluated only on the basis of the final exam.

SYLLABUS/CONTENT

General knowledge of mechanical quantities and their relative units is an essential prerequisite to the study of physical phenomena: in fact, they are recalled in the introductory part of the course.

Then, the course addresses the main topics of technical thermodynamics, hinting at the analysis of thermodynamic systems and energy transfer that characterize them.

Afterwards the course deals with Following is the study of the main heat transfer mechanisms: conduction, convection and thermal radiation. Finally, the basics of thermohygrometry are introduced, aimed at analyzing the conditions of environmental comfort and preliminary to the study of air conditioning systems. In relation to the latter, a brief mention is made of some applications in the nautical sector.

**Detailed program**

NOTES ON MECHANICS

Units of measure, scalar and vector quantities.

Kinematics: displacement, velocity, acceleration. Uniform and uniformly accelerated rectilinear motions. Uniform circular motion.

Fundamental laws of dynamics. Centripetal force, gravitational force, friction force, elastic force.

Work, kinetic energy theorem, power. Conservative and non-conservative forces, potential energy, conservation of mechanical energy law.

NOTES ON STATIC OF FLUIDS

Pressure, Stevin's law, Pascal's law, Archimedes' law, Torricelli's experience, differential pressure gauges.

THERMODYNAMICS

Thermodynamic systems, state variables, thermodynamic transformations.

Operational definition of temperature. Absolute temperature scale. Perfect gases.

Mechanical work. Operational definition of heat.

First law of thermodynamics for closed systems.

Conservation of energy and mass. Continuity equation. First law of thermodynamics for open systems.

Internal energy, enthalpy, specific heat of incompressible substances.

Internal energy, enthalpy, specific heat at pressure and constant volume of perfect gases.

Energy equation in mechanical terms. Bernoulli's equation. Distributed head losses. Concentrated head losses. Prevalence of an engine. Converging and diverging channels. Pump and turbine efficiency, closed circuit.

Pure substances: state diagrams, vapour quality, latent phase transition heat.

HEAT TRANSFER

Generalities and second law of thermodynamics (outline).

Thermal conduction: Fourier's law, thermal conductivity, conduction across a plane wall and a cylindrical surface, conductive thermal resistance, thermal resistances in series and parallel. Flat multi-layered walls and complex walls.

Thermal convection: generalities, Newton's law, forced and natural convection.

Thermal radiation: electromagnetic waves, black body, Planck’s and Wien’s laws, emissivity, gray body, absorption, reflection and transmission factors, Kirchhoff's law, selective surfaces, view factor, heat transfer between black and gray surfaces.

Combined heat transfer mechanisms: surface resistances, flat multi-layer walls. Transmittance of flat multilayer and complex walls.

THERMOHYGROMETRY AND PLANTS

Psychrometry: generalities. Thermohygrometric quantities: specific, absolute and relative humidity, specific volume, enthalpy of humid air, dew point temperature, adiabatic saturation temperature. Psychrometric chart, relative humidity measurement.

Thermohygrometric comfort. The thermoregulatory system of the human body. The thermal balance of the human body. Overall comfort indices. Local discomfort indices (outline).

Humid air transformations: adiabatic mixing, sensible heating, sensible cooling and cooling with dehumidification, adiabatic humidification.

Classification of air conditioning systems. Mass and energy balance of an air-conditioned environment. Heating system: dispersions for ventilation and transmission, sizing and calculation parameters.

RECOMMENDED READING/BIBLIOGRAPHY

Bergero S., Chiari A., Appunti di termodinamica, Aracne editrice, 2007.

Bergero S., Chiari A., Appunti di trasmissione del calore, Aracne editrice, 2012.

Bergero S., Chiari A., Appunti di termoigrometria e impianti, Aracne editrice, 2015.

Bergero S., Cavalletti P., Chiari A., Problemi di Fisica Tecnica, Dario Flaccovio, 2014.

All books are available in the library; they can be easily purchased on the main websites and are also available in electronic format.

In the AulaWeb of the course, additional teaching materials are made available to students, including handouts for the topics "General physics recalls", the complete reference bibliography, proposed and solved exercises, texts of past exams.

## TEACHERS AND EXAM BOARD

**Ricevimento:** The student reception is held at least one day a week, to be established, privileging the days on which the lessons of the course are held.
Interested students must take an appointment by sending an email to the teacher. The teacher can open the activity to other interested students, communicating it to the whole class by means of AulaWeb.
The reception can be made in the presence at the Polo of La Spezia or at the Genoa headquarter, or even with remote telematic mode.

Exam Board

ANNA CHIARI (President)

MARIO MISALE

STEFANO LAZZARI

FRANCESCO DEVIA

STEFANO BERGERO

## LESSONS

Teaching methods

The course is in Italian according to the TBL teaching method. The Team Based Learning is a teaching strategy based on independent study and collaborative learning.

The method involves the following steps. Before each lesson, the didactic contents for the independent study are assigned. On the same contents, individual and group activities are then carried out in the classroom to apply and verify the knowledge acquired: generally both multiple choice test with immediate feedback, to be solved individually or in groups, and practical problems to be analyzed and numerically solved, are also administered. These activities are intended to encourage learning through team discussion. The teacher stimulates and moderates the discussion, resuming and specifying, even with subsequent lectures, the different contents according to the critical issues that emerged.

For group activities the class is divided into teams defined by the teacher and stable for the duration of the course.

All individual and group activities are subject to evaluation.

The student's adhesion to the TBL is consequent to the acceptance of the "classroom agreement" at the beginning of the course and provides for compulsory attendance.

If a student does not join the TBL, he is exempt from the obligation to attend, can take advantage of the teaching material made available and can attend the frontal lessons, but does not participate in classroom activities and is evaluated only on the basis of the final exam.

LESSONS START

The course is in the first semester, in agreement with the academic calendar.

## EXAMS

Exam description

The final exam consists of a written test and an oral test.

The written test focuses on the numerical resolution of problems relating to the main topics of the course. The oral exam is aimed at ascertaining the theoretical knowledge of the same issues and above all the critical understanding of the problems addressed.

In the official calendar only the dates of the written tests are shown.

The date of the oral test is communicated at the end of the written test and, generally, it takes place in the week which follows the one of the written test.

Access to the oral test is allowed after passing the written test.

If the oral exam is not passed, the written exam is no longer considered valid.

During the written test, only the use of the calculator, the tables and the form provided by the teacher is allowed. The use of other notes or books is not allowed.

Assessment methods

The final evaluation is completed by the evaluation of the final exam and by the evaluation of the individual and group activities carried out in it.

The final score will be equal to the sum of the score obtained during the final exam and the score relating to the same activities, both expressed in thirtieths.

For all tests, the assessment method takes into account what is specified in the learning outcomes.

**Evaluation of the final exam**

The final test consists of a written test and an oral test: the latter is accessible only to students who have successfully passed the written test.

The score obtained in the written test does not affect the final score but defines only the exceeding or not of the threshold established for the passage to the oral test. The written test is passed with a score of ≥5.5 / 10 or ≥4.5 / 8.

The final mark of the exam, expressed in thirtieths, is established exclusively on the basis of the evaluation of the oral exam.

In fact, the final exam must be considered as a single activity: if the oral exam is not passed, the written exam will no longer be considered valid.

**Evaluation of individual and group activities**

The evaluation of all individual and group tests carried out during the course contributes to the acquisition of an overall score between 0 and 4 out of thirty.

## FURTHER INFORMATION

All information about the course (reception hours for students, teacher communications, educational materials, etc.) are available and constantly updated on AulaWeb.