FLUID MACHINES DESIGN

Academic Year 2023/2024 - Teacher: STEFANO MAURO

Expected Learning Outcomes

The course is divided into two parts. The first part of the course concerns the design of wind turbines, while the second is devoted to the study of reciprocating internal combustion engines. The course provides the basis for the aerodynamic design of wind turbines (horizontal and vertical axis wind turbines) and the evaluation of their performance. With regard to reciprocating internal combustion engines (ICE) the course provides students with the basis for the design, focusing on key aspects such as Performance Optimization, Engine Cycle Simulation, ICE Combustion, Pollutant Formation and Control and integration in hybrid propulsion systems. During the course will be carried out numerical simulations on the computer.

Course Structure

Lectures (39 hours) and numerical exercises (52 hours).

Required Prerequisites

FLUID MECHANICS (Formal)

Attendance of Lessons

The presence during the lessons is mandatory

Detailed Course Content

RECIPROCATING INTERNAL COMBUSTION ENGINES Classification. Maximum efficiency, internal thermodynamic efficiency and organic efficiency. - Combustion at constant volume and/or constant pressure. - Feeding air. - Filling in 4-strokes engines: general data, detailed study, analysis of the distribution equipment. Filling in 2-strokes engines: general data, outlines of washing, analysis of the washing process. - Feeding fuel in spark-ignition engines. General requirements. Elementary carburettor. Injector - - Feeding fuel in the compression-ignition engines. Requirements in terms of atomization and penetration of the jet. Injection Systems. Common Rail System. - Biofuels. - Notes on Supercharging. - Combustion – General data- Combustion in spark-ignition engines - Octane number. ICE-SI Combustion. - Combustion in compression-ignition engines . Cetane number. - Emissions of polluting agents: harmful effects, mechanisms of formation, influence of operation parameters. - Numerical evaluation of the Heat Release in ICE-SI; - Numerical evaluation of the Limit Cycle of a ICE-SI; - Numerical evaluation of ICE pollutants. - Hybrid powertrains

WIND TURBINES DESIGN Wind turbine technology. Fundamental concept of wind turbine engineering. Wind turbines mathematical models. Airfoil characterization. Lift and drag coefficient. Blade Element Momemtum Theory. Wind rotor performance evaluation. Application to Horizontal Axis Wind Turbines and to Vertical Axis Wind Turbines. Power curves. Power and Torque coefficients. Wind Rotor Solidity. Off design performance evaluation. -Fluid Dynamic Design of an Horizontal Axis Wind Turbine; -Fluid Dynamic Design of a Vertical Axis Wind Turbine.

SUBSONIC WIND TUNNEL DESIGN Type of wind tunnels. Wind tunnel components: Test section, diffuser, corners, Fan, Settling chamber. Honeycomb and screens. Subsonic Wind tunnel design. Power consideration. Section loss coefficients. Energy Ratio. Test section Flow quality. -Fluid Dynamic Design of a Subsonic Wind Tunnel.

Textbook Information

[1] J.B. Heywood: "Internal combustion engine fundamentals", Mc Graw Hill 
[2] G.Ferrari: "Motori a Combustione Interna", Società Editrice Esculapio 
[3] Battisti L.: Gli impianti motori eolici, Green Place Energies 
[4] Sphera DA, editor. Wind turbine technology: fundamental concepts of wind turbine engineering. 
[5] Barlow, Rae, Pope: Low Speed Wind Tunnel Testing. John Wiley & Sons, Inc. Third Edition
[6] G.Ferrari: "Internal Combustion Engines", Società Editrice Esculapio
[7] L. Guzzella, A. Sciarretta: Vehicle Propulsion Systems, Introduction to Modeling and Optimization. Springer
[8] S. Onori, L. Serrao, G. Rizzoni: Hybrid Electric Vehicles Energy Management Strategies. Springer

Course Planning

	Subjects	Text References
1	Internal Combustion Engines	[1] [2] [6]
2	Hybrid propulsion systems	[7] [8]
3	Wind turbines	[3] [4]
4	Wind tunnels	[5]

Learning Assessment

Learning Assessment Procedures

The exam consists of an oral test. During the lessons, application exercises of the course contents are carried out, which aim to focus the students' attention on engineering problems, in particular on wind turbines and internal combustion engines. The application exercises of the course contents and the topics covered during the lectures are discussed during the oral exam. The evaluation during the oral interview will be based on: knowledge of the contents, the relevance of the answers with respect to the questions asked, the property of technical language, the ability to make connections between the contents of the program.

To guarantee equal opportunities and in compliance with current laws, students can request a meeting in order to plan any compensatory and/or dispensatory measure, according to the educational goals and specific needs. In this case, it is advisable to contact the CInAP (Centre for Active and Participated Integration - Services for Disabilities and/or SLD) professor of the Department where the Degree Course is included

Examples of frequently asked questions and / or exercises

The candidate describes the ICE limit cycle

The candidate explains how to evaluate the heat release in ICEs

The candidate describes how to calculate the product of combustions in ICEs

The candidate explains the chemical kinetics of NOx in ICEs

The candidate describes the features and the principles of the hybrid propulsion systems

The candidate describes the HAWT design methodologies

The candidate describes the VAWT design methodologies

The candidate describes the wind tunnel fluid dynamic design methodologies

Degree Course in

Mechanical Engineering