OVERVIEW

The unit provides the students with the fundamental skills to interpret the processes, as well as the technologies, related to fluid and thermal machines. This allows the student to master the basic principles of thermodynamics and fluid dynamics when applied to the design and the analysis of energy conversion equipment, as well as to address the functional behavior of fluid machines both in themselves and when components of power systems.

AIMS AND CONTENT

LEARNING OUTCOMES

The aim of the course is to provide the student with the fundamentals of the study of volumetric and dynamic fluid machines in order to analyze their functional behavior and evaluate the main performance aspects.

AIMS AND LEARNING OUTCOMES

At the end of the teaching unit the student will be able to:

• Describe and analyze operations of positive displacement and dynamic fluid machines, identifying strengths and weaknesses.
• Evaluate the main operational, performance and energy parameters of fluid machines, comparing the available options.
• Reproduce and discuss the characteristic curves of the different types of machines.
• Select the quantities related to the environmental impact of the machines.

Thanks to the attendance of the planned educational activities, it will be possible to obtain the following skills: ability to manage own social interactions, collaborative attitude, constructive communication in different environments (social competence).

PREREQUISITES

Basic knowledge of thermodynamics and fluid mechanics.

TEACHING METHODS

The teaching unit is organized in lectures and numerical practices.

Students with a certified learning disability (DSA), a disability, or other special educational needs are invited to contact the instructor at the beginning of the unit to discuss teaching and examination arrangements that, while respecting the learning objectives of the course, take individual learning needs into account and provide appropriate accommodations.
Please also note that requests for exam accommodations or exemptions must be submitted using the form available at this link https://modulionline.unige.it/richiesta-adattamenti#no-back, to the course professor, the DIME contact person (federico.scarpa@unige.it), and the relevant office ( inclusione.studenti@info.unige.it) at least seven working days before the examination, in accordance with the guidelines available at this link https://unige.it/disabilita-dsa/richiesta-servizi
 

SYLLABUS/CONTENT

A. Positive displacement fluid machines

- Introductory concepts

Classification of fluid machines. The energy equation and the expression of work. Conversion efficiency in fluid machinery. Work exchange in the positive displacement fluid machines .

- Reciprocating internal combustion engines (ICE)

Historical overview and fields of application. Basic knowledge on ICE: classification, components and nomenclature, main operational parameters. Ideal and real operation of 2 and 4 stroke engines. Indicated diagrams, indicated and brake mean effective pressure, engine power correlations. Reference thermodynamic cycles for spark ignition (SI) and diesel engines. Regular and abnormal combustion processes in ICE. Part load operation of SI and diesel engines. ICE performance curves. Supercharging and turbocharging: basic plants design, application fields, operational issues, thermodynamic cycles, compressor and turbine power. ICE pollutant emissions: influence of combustion process and operational engine parameters on exhaust emissions, emission control systems and aftertreatment devices for SI and diesel engines.

- Positive displacement compressors and pumps

Reciprocating displacement compressors: operating principle, constructive characteristics, ideal and real working cycle, flow rate control systems. Rotary displacement compressors: vane, lobe, liquid ring, screw compressors. Volumetric pumps: alternative and rotary machines, working principle, construction types. Characteristic curves. Fluid machine-circuit matching.

B. Turbomachinery

- Classification, structure, examples, and applications of turbomachinery

Drivers and operators. For energy conversion, for propulsion. Axial and radial. Single-stage and multi-stage. Compressible fluid, incompressible fluid. Gas, steam, hydraulic.

- Geometric characteristics of turbomachinery

Meridian plane, frontal section, development of axisymmetric flow surfaces. Geometric definition of blade profiles.

- Fundamental equations of turbomachinery

One-dimensional theory. Continuity equation. Energy equation for open systems: in the absolute system, in the relative system. Definition of pressure and total enthalpy. Compression and expansion transformations in the enthalpy plane. Calculating velocity in ducts. Fundamental kinematics of turbomachinery, velocity triangles. Momentum equation in a blade. Momentum moment. Euler equation of turbomachinery, energy exchange in blades. Calculating forces in the blades of axial machines.

- Axial turbines

Operation, design, velocity triangles, reaction rate. Characteristic curves.

- Axial compressors

Operation, design, velocity triangles, reaction rate. Pressure rise. Characteristic curves.

- Steam turbines

Functional characteristics and architecture.

- Gas turbines

Functional characteristics and architecture.

- Hydraulic turbines

Functional characteristics and architecture.

- Pumps, fans, and centrifugal compressors

Operation, design, velocity triangles, reaction rate. Head and pressure rise. Efficiencies, characteristic curves, cavitation.

This unit contributes to the achievement of the following Sustainable Development Goals of the UN 2030 Agenda: Objectives 7 (Clean and Affordable Energy) and 13 (Fighting climate change).

RECOMMENDED READING/BIBLIOGRAPHY

Notes of the unit will be available in the Aulaweb page for all the registered students, including student workers.

• R. Della Volpe - “Macchine” - Liguori Editore, 2011.
• V. Dossena, G. Ferrari, P. Gaetani, G. Montenegro, A. Onorati, G. Persico - “Macchine a fluido” - CittàStudi Edizioni, 2020.
• G. Cornetti, F. Millo - “Macchine idrauliche”, “Macchine a gas” - Il Capitello, 2015.
• G. Ferrari - "Motori a combustione interna" - Esculapio, 2016.
• O. Acton, C. Caputo - “Compressori ed espansori volumetrici”, UTET, 1992.
• O. Acton - “Turbomacchine”, UTET, 1992.

TEACHERS AND EXAM BOARD

LESSONS

LESSONS START

https://corsi.unige.it/en/corsi/1941/studenti-orario

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

Oral exam on the topics presented during the lessons and exercises.

Students with a certified learning disability (DSA), a disability, or other special educational needs are invited to contact the instructor at the beginning of the unit to discuss teaching and examination arrangements that, while respecting the learning objectives of the course, take individual learning needs into account and provide appropriate accommodations.
Please also note that requests for exam accommodations or exemptions must be submitted using the form available at this link https://modulionline.unige.it/richiesta-adattamenti#no-back, to the course professor, the DIME contact person (federico.scarpa@unige.it), and the relevant office ( inclusione.studenti@info.unige.it) at least seven working days before the examination, in accordance with the guidelines available at this link https://unige.it/disabilita-dsa/richiesta-servizi

ASSESSMENT METHODS

The oral examination will be focused on the topics treated during the lessons and will be aimed at evaluating not only the fulfilment of an adequate knowledge level, but also the acquisition of critical analysis skills on the topics of the exam and the aptitude of correlation of different topics. The clarity of presentation, the correct use of technical terminology and the ability to reproduce technical diagrams will also be assessed.

FURTHER INFORMATION

Ask the professors for other information not included in the teaching schedule