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Scheda Riassuntiva
Anno Accademico 2019/2020
Tipo incarico Dottorato
Insegnamento 094721 - AERODYNAMICS AND AEROACOUSTICS OF ROTORS
Docente Vigevano Luigi
Cfu 5.00 Tipo insegnamento Monodisciplinare

Corso di Dottorato Da (compreso) A (escluso) Insegnamento
MI (1377) - INGEGNERIA AEROSPAZIALE / AEROSPACE ENGINEERINGAZZZZ094721 - AERODYNAMICS AND AEROACOUSTICS OF ROTORS

Programma dettagliato e risultati di apprendimento attesi

Objectives

Main learning objective

The course is aimed at presenting the fundamental aerodynamic and aeroacoustic phenomena experienced by a helicopter rotor in different flight conditions. The understanding imparted will be on both the physical processes and the numerical and theoretical models needed to correctly represent them.

Methodological learning objective

The student will be trained in carrying on an applied research project.

 

Description of the subjects

1) Rotor aerodynamic environment

2) Momentum theory in hover and axial flight: induced velocity, non-ideal effects, power loading, figure of merit, flow regimes in axial flight, autorotation.

3) Blade-element theory in axial flight: aerodynamic coefficients, analytical solutions, induced tip losses, blade-element/momentum theory.

4) Momentum and blade-element theories in forward flight: simple models of the induced velocity field (Glauert, Pitt & Peters, Mangler & Squire).

5) Rotor airfoil requirements and static airfoil characteristics

6) Unsteady airfoil aerodynamics: quasi-steady thin airfoil theory, unsteady thin-airfoil theories in the frequency domain (Theodorsen's, Loewy's, Sears') and in the time domain (indicial response methods: Wagner's, Kussner's, time-varying velocity). Approximation of the indicial response for compressible flow.

7) Dynamic stall: phenomenology, stall regimes, effects of operating parameters, dynamic stall models, active control.

8) Aerodynamic interactions: rotor-fuselage and rotor-empennage interactions; main rotor-tail rotor interactions; fuselage-rotor interactions.

9) Rotor wakes: general features in hover and forward flight; tip vortex and 1D vortex models; blade-vortex interactions; vortex models of the rotor wake: prescribed wake and free wake models; other CFD approaches.

10) Fundamental of acoustics: integral solution of the non-homogeneous wave equation, elementary solutions, multipoles  (monopole, dipole, quadrupole), free space Green function, Doppler effect.

11) Fundamentals of aeroacoustics: Lighthill' acoustic analogy, noise from a turbulent jet; Ffowcs Williams-Hawkings approach and its different forms of implementation; Kirchoff method; vortex sound theory.


Note Sulla Modalità di valutazione

Presentation and discussion of a personal project on one of the item presented during the course


Intervallo di svolgimento dell'attività didattica
Data inizio
Data termine

Calendario testuale dell'attività didattica
 

Bibliografia
Risorsa bibliografica facoltativaJ. G. Leishman, Principles of helicopter aerodynamics - 2nd Edition, Editore: Cambridge University Press, Anno edizione: 2006, ISBN: 978-0-521-85860-1
Risorsa bibliografica facoltativaA. Hirschberg, S.W. Rienstra, An introduction to aeroacoustics http://www.win.tue.nl/~sjoerdr/papers/les-swr-mh.pdf

Software utilizzato
Nessun software richiesto

Mix Forme Didattiche
Tipo Forma Didattica Ore didattiche
lezione
26.0
esercitazione
0.0
laboratorio informatico
0.0
laboratorio sperimentale
0.0
progetto
0.0
laboratorio di progetto
30.0

Informazioni in lingua inglese a supporto dell'internazionalizzazione
Insegnamento erogato in lingua Inglese
Disponibilità di materiale didattico/slides in lingua inglese
Disponibilità di libri di testo/bibliografia in lingua inglese
Possibilità di sostenere l'esame in lingua inglese

Note Docente
schedaincarico v. 1.8.0 / 1.8.0
Area Servizi ICT
02/02/2023