MACHINERY A
cod. 18091

Academic year 2008/09
3° year of course - First semester
Professor
Academic discipline
Macchine a fluido (ING-IND/08)
Field
Ingegneria meccanica
Type of training activity
Characterising
45 hours
of face-to-face activities
5 credits
hub:
course unit
in - - -

Learning objectives

The aim of the course is to give the basic knowledge on the theory of Fluid Machinery, both as stand-alone units and as Power Systems components. Students will be provided with fundamentals required for the understanding of most important energy conversion processes, which will be then used in the analysis of the most widely used power plants.

Prerequisites

<br />A basic knowledge of fundamentals of Mathematics, Physics, Thermodynamics and Fluid Mechanics is required.

Course unit content

<br />Energy demands in Italy and in the world. Fossil and renewable energy sources. Power Systems and Fluid Machinery: characteristics and classification.<br />Thermodynamics: 1st and 2nd law. Gas and vapours. Mass, energy, momentum conservation equations and their applications. Work done by fluid systems in rotating ducts: radial and axial turbomachinery.<br />Energy from fossil fuels: combustion processes and fuel properties. Mass balance, combustion products composition, fuel/air ratio.<br />Thermodynamic cycles. Conversion efficiencies in power plants, overall efficiency and specific fuel consumption. Cost of energy and utilisation coefficient.<br />Turbomachinery working on compressible fluid. De St.Venant equation, compressibility effects and dynamic pressure, Hugoniot equation, Mach number, ideal nozzles and diffusers. Mass flow rate in nozzles. Compression and expansion: representation on thermodynamic diagrams, efficiencies.<br />Compressors and pumps: fundamentals, head, matching with piping system. Centrifugal turbomachinery. Characteristic curves. Pumps: cavitation and NPSH. Dynamic compressors: axial stage, stall and surge, characteristic curves of multi-stage machines, choking and operating range.<br />Steam plants. Fundamentals: thermodynamic cycles, Rankine and Hirn cycles (superheated). Steam generators: fundamentals and layouts, efficiency of the steam generator, superheaters, air pre-heaters. Condensers and cooling towers. Thermal regeneration and regenerative cycles.<br />Gas turbines: fundamentals, thermodynamic cycles (ideal and real), efficiency and specific work, cycle optimisation. Combustion chamber and air/fuel ratio. Turbine inlet temperature (TIT): effects on the efficiency, blade cooling, materials and alloys.<br />Internal combustion engines: fundamentals, ideal thermodynamic cycles, power output. Brake mean effective pressure (bmep). Volumetric efficiency. Characteristic curves.

Full programme

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Bibliography

<br /><br /><br />O.Acton, C.Caputo, Macchine a fluido, vol.1, 'Introduzione allo studio delle Macchine', UTET, 1979.<br /><br />O.Acton, C.Caputo, Macchine a fluido, vol.2, 'Impianti Motori', UTET, 1992.<br /><br />O.Acton, Macchine a Fluido, vol.3, “Turbomacchine”, UTET, 1990.<br /><br />G.Ferrari, “Motori a Combustione Interna”, Il Capitello, 1990.<br /><br />C.Caputo, “Gli impianti convertitori di energia”, Masson, 1989.<br />C.Caputo, “Le turbomacchine”, Masson, 1989.

Teaching methods

<br />Lectures and numerical examples on course subjects.<br />Final examination is oral only.

Assessment methods and criteria

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Other information

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