Lecturer: Roberto Sala  

Course name: Machines
Course code: 062270
Degree course: Ingegneria Meccanica
Disciplinary field of science: ING-IND/08
L'insegnamento è caratterizzante per: Ingegneria Meccanica
University credits: CFU 7
Course website: n.d.

Specific course objectives

The purpose of the course is to illustrate the usual thermal and hydraulic power plants and the characteristics of thermal and hydraulic machines used for energy exchanges. Design and operating characteristics are described and particular attention is focused on selection criteria in order to maximize plant efficiency.

Course programme

General principles
Thermodynamic and Fluid-dynamic fundamentals: mass and energy conservation. Adiabatic flow in ducts: nozzles and diffusers, subsonic and supersonic flow. Relative motion, Euler’s equation.

Pumps
Classification and selection criteria. Operating parameters: head, efficiencies and power required. Performance curves, design and off-design operating conditions: flow rate control methods. Cavitation, NPSH required. Affinity laws for turbomachines. Interaction between pump geometry and performance required.

Hydraulic turbines
Hydraulic plants and selection criteria. Pelton, Francis and Kaplan: operating characteristics and performance curves.

Gas compressors
Reciprocating and turbo dynamics compressors: classification, selection criteria and operating characteristics. Instability problems (choking, surge and stall).

Gas-turbine power plants
Simple Joule's ideal cycle: efficiency and work. Complex and actual cycles. Effect of maximum temperature and compression ratio on power plants performances.

Steam power plants
Rankine-Hirn cycle: efficiency and work. Operating characteristics. Boilers and condensers. Multi-stage turbine configuration.Combined cycles. Cogeneration plants.

Reciprocating internal combustion engines
Ideal cycles: efficiency and work. Thermal and mechanical losses. Actual cycles: power and efficiencies. Fuels. Carburettors and fuel injectors.

Course entry requirements

Course structure and teaching

Lectures (hours/year in lecture theatre): 33
Practical class (hours/year in lecture theatre): 39
Practicals / Workshops (hours/year in lecture theatre): 0

Suggested reading materials

G. Cornetti. Macchine Idrauliche e Termiche. Il Capitello - Torino.

R. Della Volpe. Macchine. Liguori Editore.

Testing and exams