The specific aim of this module is to achieve cognitive and practical skills in experimental aerodynamics applied to the aeronautic field and more generally to the industrial and environmental engineering fields.
Lectures are also focused on arguments that deal with the fundamental theory of aeroacoustics, including theoretical design problems. Practical exercises and experimental experiences in the department laboratory will deepen aspects related to noise measurements with particular attention on their application in the aeronautical field (ex.: compressible jets and wall flows ).
Having successfully complete the module, the student will be able to recognize, acquire and analyze aeroacoustics and aerodynamics problems with conventional and advanced instrumentation and elaboration techniques.
Lectures are also focused on arguments that deal with the fundamental theory of aeroacoustics, including theoretical design problems. Practical exercises and experimental experiences in the department laboratory will deepen aspects related to noise measurements with particular attention on their application in the aeronautical field (ex.: compressible jets and wall flows ).
Having successfully complete the module, the student will be able to recognize, acquire and analyze aeroacoustics and aerodynamics problems with conventional and advanced instrumentation and elaboration techniques.
teacher profile teaching materials
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.
Wind tunnels: low speed, high speed and anecoich.
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.
Programme
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.
Wind tunnels: low speed, high speed and anecoich.
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.
Core Documentation
Lecture notes.Reference Bibliography
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. J.B. Barlow, W.H. Rae and A. Pope. Low speed wind tunnel testing. John Wiley and Sons, Inc. 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).Type of delivery of the course
The course is taught by lectures and theoretical exercises. The educational objectives will be pursued also by some laboratory experiences. The laboratory experiences are by group and the theoretical exercises are individual. All practical applications are mandatory. For the laboratory experiences, velocity and pressure measurement instrumentations will be used on laboratory scale experiments like small jet or propeller. Two educational trips are foreseen. One will bring the students to the Italian Research Center for Aerospace and the other to the ship model basin. The last will take place after a series of lectures on optical measurement techniques and a series of seminar from experts in the field. After each lecture, the presentation and the annexed material will be promptly uploaded on Moodle.Attendance
Class attendance, although recommended, is not mandatory. Theoretical and practical applications are mandatory.Type of evaluation
Evaluation of the level of learning achieved by the student will be verified by oral exam with a possible discussion on the laboratory experience and theoretical exercises. All the reports on practical applications are due by one week from the end of the course and they should be redacted in English.