General concepts: airfoils and wings.
Potential flows in 2D and 3D, Green's theorem and Green's function, BEM methods.
The theory of infinite (Glauert) and finite (Prandtl) wings, the lifting line and surface.
Boundary layer theory: Falkner-Skan solutions and integral methods.
WInd tunnels: classifications, general properties, design.
Turbulence: general equations for incompressible flows, modelling, Kolmogorov theory, turbulent boundary layer.
COmputations Fluid Dynamics (CFD): discretization of the governing equations using Finite Difference method and Finite Volumes; Application of industrial codes.

- Notes distributed by the teacher
- Anderson, Jr. J.D. , Fundamentals of Aerodynamics, 2nd Editino, McGraw Hill, 1991.
- Mattioli E. Aerodinamica, Levrotto e Bella, Torino, 1989.

Aircraft components and their role in flight.
Elements of steady aerodynamics of fixed wings: lift and drag coefficients, polar curve of the aircraft; aerodynamic efficiency; finite wings.
Dynamics of vehicle as a material point.
Fixed-wing aircraft performance: power curve, range and endurance; climb performance, ceiling.
Glide performance and climb hodograph.
Load factor: steady turn, flare maneuver, gust response. V-n diagram, gust envelope and flight envelope.
Take off and landing performance.

Nonlinear algebraic equation solution: iterative methods; Newton-Raphson method.
Methods for the solution of ordinary differential equation systems in time domain: first-order form and solution through: (i) eigenvector method, (ii) reference base change, (iii) integration by exponential matrix form.
Fourier series, Fourier transform, Laplace transform, transfer function, impulsive, indicial and harmonic response.
Linear differential operators: eigenfunctions and eigenfunction method for the solution of systems of partial differential equations.
Methods of Galerkin and Rayleigh-Ritz.
Calculus of variation: functional and Euler-Lagrange equations; trasversality conditions; the brachistochrone problem; Riccati equation for the optimal control method.

Mc Cormick, B.W., Aerodynamics, Aeronautics, and Flight Mechanics. Wiley and Sons, 1995.
Hildebrand, F.B., Methods of Applied Mathematics. Dover Publications, NY, 1992.
Etkin, B., Dynamics of Flight-Stability and Control. John Wiley & Sons, Inc., 1996.

During the lectures, the teacher will suggest the student the most efficient way to use the proposed references, and will provide them with lecture notes.

AIRCRAFT:
Trim and static stability
Maneouvrability
Controls effectiveness
General equations of dynamics
Stability derivatives
Flight stability
Response to controls
Flight control systems
ELICOTTERO:
Overview
Controls
Inflow models
Performance
Rotor dynamics

C. Casarosa, "Meccanica del Volo", Pisa University Press
B. Etkin & L.D. Reid, "Dynamics of flight - Stability and Control", John Wiley and Sons
D. McLean, "Automatic Flight Control Systems", Prentice Hall
G. D. Padfield, "Helicopter Flight Dynamics", Blackwell Science
M. Arra, "L'elicottero", Biblioteca Tecnica Hoepli
G. Guglieri, M. Porta, A. Quinci, "Meccanica del volo dell'elicottero. Appunti delle lezioni", Esculapio

PART 1: ELEMENTS OF GAS_DYNAMICS
Introductory concepts; isoentropic compressible flows and normal shock waves; design of gas-dynamic systems. Fanno and Rayleigh flows. Oblique shocks and odograph plane. Prandtlt-Meyer expansion. Compressible potential flows, linear theory and supersonic thin qirfoil. Characteristic method (in 2D and steady).
PART 2: AICRAFT PROPULSIVE SYSTEMS
Introductory concepts and classification. Performance parameters. Definition of thrust and power. Definition of efficiencies. Turbo-gas cycle (real and ideal). Simple turbojet; turbofan; ramjet; turboprop. Propellers and blade element theory. Nozzles and diffusera (sub- and super-sonic). Elements of combustion.

Several practical excercises are carried out during the course.

Notes distributed by the teacher
HILL P., PETERSON C., “MECHANICS AND THERMODYNAMICS OF PROPULSION”, ADDISON WESLEY PUBL., 2ND ED., 1992.
CUMPSTY N., “JET PROPULSION”, CAMBRIDGE UNIV. PRESS, 1997.

The Aircraft Structures course is part of the activities of the Constructions and aerospace structures (ING-IND/04 SSD).

The teaching program is structured to provide students with knowledge and skills in the structural design of aeronautical components, using methods widely used in the aircraft conceptual and preliminary design phases.

The teaching program is divided into 36 lectures (equal to 9 CFU) divided into the following five main sections:

1) Beam theory: bidirectional bending, torsion, torsion of closed thin-walled beams ( Bredt-Batho theory), torsion of open thin-walled beams, shear of open and closed thin-walled beams (shear center), torsion and shear of multicell thin-walled beams, tapered beams.

2) Introduction to aircraft design and semi-monocoque structures: failure criteria of fragile and ductile materials, loads acting on aircraft, regulations for aircraft design, box-wing concept, fuselage structure, fuselage, and box-wing stress and strain analysis, structural idealization.

3) Thin plates Kirchhoff's theory: in-plane problem, bending problem, eigenfunctions method for simply supported plates.

4) Introduction to structural instability: buckling of the beam (Euler's critical load); buckling of thin plates; buckling on aeronautical structures.

5) Thin shells: shells in the form of a surface of revolution and loaded symmetrically with respect to their axis, pressurized fuselage stress analysis.

- T.H.G. Megson, Aircraft Structures for Engineering Students, Arnold, London, 1999 (for contents 1, 2, 3 and 4 of the syllabus)

- C.T. Sun, Mechanics of Aircraft Structures, John Wiley & Sons, New York, 1998 (for contents 1, 2, 3 and 4 of the syllabus)

- S.P. Timoshenko, Theory of Plates and Shells, McGRAW-hill, 1959 (for contents 3 and 5 of the syllabus)

- Lectures notes by the teacher (for all the contents of the syllabus)

The educational material used by the teacher from time to time is indicated during lectures. The lecture notes are made available on the Moodle platform to facilitate their use for both attending and non-attending students. On the same platform, are also made available the specifications of the project the students have to perform during the year, as well as a collection of written tests of previous exams, to provide students with a valid and realistic test bench for the final exam.

Fundamentals:
Mechanics of fluids: Incompressible and compressible conservation laws, dimensional analysis, asymptotic solutions. Sound Field; Wave equation for fluids, speed of sound and acoustic energy; Diffraction; Geometrical acoustics; waves in solids; Sound frequency analysis; Decibel and Sound Pressure Level; Acoustic Filters; Sound fields summation; Interference and frequency contents.

Waves equation
Wave equation in a field without sources; Simple and harmonic solutions; Sound Intensity; Energy and specific energy; waves reflection and transmission; Sound generation and transmission mechanisms. Sound sources: Monopole; Dipole; Quadrupole.

Digital signal processing and probability fundamentals.

Acoustic measurement facilities
Anechoic chambers; reverberant chambers.

Quantitative measures of sound
Mathematics fundamentals; Fourier analysis; Measurements systems; acoustic sources characterization by means of microphone measurements.

Experimental techniques for turbulent flows measurements
Hot wire anemometry. Single and multi components; Laser Doppler Anemometry; Particle Image Velocimetry; Laser Induced Fluorescence.

Optical methods for the analysis of density fields
Interferometry, Schlieren, Shadowgraph.

Measurements in aerodynamic wind tunnels
Pitot tube, pressure transducers, mass flow rate meters, thermal measurements with thermocouples; force measurements with dynamometric balances, acoustic measurements.

P.K. Kundu. Fluid Mechanics. Academic Press, San Diego, USA, 1990.

L. D. Landau and E. M. Lifshitz, Fluid Mechanics 2ed., Course of Theoretical Physics vol. 6, Butterworth-Heinemann (1987)

H.H. Hubbard, editor. Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 1 Noise
Sources; Volume 2 Noise Control (Nasa Reference Publication 1258). Acoustical Society of
America, 1995.

M.S. Howe. Acoustics of Fluid-Structure Interactions. Cambridge University Press, Cambridge,
UK, 1998.

W.K. Blake. Mechanics of Flow-induced Sound and Vibration, Volume I. Academic Press,
Orlando, 1986

Thomas J. Mueller, Aeroacoustic Measurements, Springer; 1 edition (2002)

Stavros Tavoularis, Measurement in Fluid Mechanics, Cambridge University Press (2005).

Lecture notes.

The Analysis of Aeronautical Structures course is part of the activities of the Constructions and aerospace structures (ING-IND/04 SSD).

The teaching program is structured to provide students with knowledge and skills in the structural design of aeronautical components, using methods widely used in the aircraft detailed design phase.

The teaching program is divided into 36 lectures (equal to 9 CFU) divided into the following eight main sections:

1) Tensor Calculus Fundamentals: N-th order tensors. Tensor operations. Curvilinear coordinates. Covariant and contravariant base vectors. Vectors and tensors in curvilinear coordinates. Differential operators in curvilinear coordinates.

2) Kinematics of Deformable Continua: Lagrangian and Eulerian descriptions of motion. Finite strain theory. Displacement and deformation gradient tensors. Polar decomposition theorem. Lagrangian and Eulerian finite strain tensors (Cauchy-Green and Eulero-Almansi). Rates of deformation tensors. Linearization of the finite strain theory (infinitesimal strain theory). Material and spatial descriptions of the continuity equation.

3) Dynamics of Deformable Continua: Material and spatial forms of linear momentum balance, Cauchy's theorem. Cauchy and Piola-Kirchhoff stress tensors. Material and spatial forms of the angular momentum balance. Material and spatial forms of the mechanical energy balance.

4) Thermodynamics of Deformable Continua: Material and spatial forms of the energy balance. Stokes' heat flux theorem. Material and spatial forms of the thermodynamic energy balance. The second law of thermodynamics.

5) Constitutive relations theory: Noll's axioms. Limitations on the constitutive relations due to the second law of thermodynamics. Constitutive relations for thermoelastic materials: definition of isothermal elastic tensor, thermal stress tensor, and thermal conductivity tensor. Constitutive equation for linear isotropic thermoelastic materials.

6) Thermoelastic problems in aeronautical structures: Uncoupled thermoelastic formulation. Initial boundary value problem of the heat conduction equation. Thermal stress analysis for elastic bodies subjected to external and thermal loads: Euler-Bernoulli beam and Kirchhoff plate.

7) Finite Element method: Strong and weak forms of the uncoupled thermoelastic problem. The relation between strong and weak forms and boundary conditions. Virtual work principle. Discretization and definition of shape functions. Shape function choice criteria. Evaluation of element mass, stiffness and damping matrices. Evaluation of equivalent nodal loads vector. Assembly procedure. The imposition of displacement constraints. Conformal elements. Non-conformal elements – patch test. Isoparametric elements. Standard methods for shape functions construction. Applications in aeronautical problems: truss, beam, plate, and shell.

8) Introduction to the code Autodesk Inventor: Geometric preprocessor. Material properties definition. Constraints and external loads imposition. Solution methods. Post-processing. Structural analysis of a wing and/or a fuselage.

- M.E., Gurtin, An Introduction to Continuum Mechanics, Academic Press, 1981 (for contents 1, 2, 3 and 5 of the syllabus)

- Boley, B.A, Weiner. J.H., Theory of Thermal Stresses, John Wiley & Sons, New York, 1960 (for contents 4, 5 and 6 of the syllabus)

- Thomas J.R., Hughes, ‘The Finite Element Method – Linear Static and Dynamic Finite Element Analysis,’ Dover, 2000 (for content 7 of the syllabus)

- T.H.G., Megson, Aircraft Structures for Engineering Students, Arnold, London, 1999 (for content 7 of the syllabus)

- Lectures notes by the teacher (for all the contents of the syllabus)

The educational material used by the teacher from time to time is indicated during lectures. The lecture notes are made available on the Moodle platform to facilitate their use for both attending and non-attending students. On the same platform, are also made available the specifications of the project the students have to perform during the year, as well as a collection of written tests of previous exams, to provide students with a valid and realistic test bench for the final exam.

Teaching Unit I
Initial sizing
MTOW estimate
Mission profiles
Aerodynamic and structural initial sizing
Propulsion integration
Lofting

Teaching Unit II
Fundamentals of multidisciplinary optimization
Local and global optimization methods
Multiobjective optimization
Multifidelity optimization
Surrogate models and metamodelling
DOE

Teaching Unit III
Knowledge-Based Engineering
Design in presence of technological and operative uncertainties
Uncertainty quantification
Robust optimization
Reliability-based optimization
Stochastic and adaptive metmodelling (Kriging, RBF, ...)

Teaching Unit IV
Tools and methods of analysis
Introduction to FRIDA (FRamework for Integrrated Design in Aeronautics) package
Introduction to GA (Genetic Algorithm) and PSO (Particle Swarm OPtimization)
Integration of simulation models

- Lecture Notes
- Daniel P. Raymer, Aircraft Design: A Conceptual Approach, Volume 1, AIAA education series, ISBN 1563478307, 9781563478307
- Sobieszczanski-Sobieski, Alan Morris, Michel van Tooren, "MULTIDISCIPLINARY DESIGN OPTIMIZATION SUPPORTED BY KNOWLEDGE BASED ENGINEERING", Wiley, 2015

An introduction to the 2 dofs semi-rigid wing model, and derivation of the governing equations through application the Lagrangian formulation. Steady and quasi-steady, 2D, aerodynamic models for the aeroelastic analysis of the semi-rigid wing model. Study of aeroelastic flutter and divergence.

Theodorsen theory for 2D unsteady aerodynamics. V-g method for flutter analysis. Padè approximants of the `lift deficiency function' and related finite-state aeroelastic model. Correlation between Theodorsen theory and Wagner theory.

Aeroelastic modelling of 3D wings: bending-torsion structural dynamics model, `strip theory' aerodynamic model and application of the Galerkin method. Extension to swept wing analysis. Aeroelastic stability analysis.

Unsteady, 3D aerodynamics: incompressibe, inviscid flows; diffferential formulation for quasi-potential incompressible flows; boundary integral formulation for quasi-potential flows and panel method for its numerical solution. Definition of the aerodynamic matrix for aeroelastic stability analysis. Rational matrix approximation of the aerodynamic matrix, corresponding finite-state aeroelastic model and flutter analysis.

Aeroelastic model of wing section with trailing-edge flap. Actuation of flap for flutter suppression, as derived from application of optimal control theory with inclusion of an observer.

Bisplinghoff, R.L., Ashley H., Halfman, R., Aeroelasticity. Dover Publications, 1996.
Hodges, D.H. and Pierce, A., Introduction to Structural Dynamics and Aeroelasticity. Cambridge Aerospace Series, 2002.

During the lectures, the teacher will suggest the student the most efficient way to use the proposed references, and will provide them with lecture notes.