EXPERIMENTAL METHODS FOR FLUID MACHINERY AND ENERGY SYSTEMS

EXPERIMENTAL METHODS FOR FLUID MACHINERY AND ENERGY SYSTEMS

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iten
Code
60459
ACADEMIC YEAR
2018/2019
CREDITS
6 credits during the 2nd year of 9270 Mechanical Engineering - Energy and Aeronautics (LM-33) GENOVA
SCIENTIFIC DISCIPLINARY SECTOR
ING-IND/08
LANGUAGE
Italian
TEACHING LOCATION
GENOVA (Mechanical Engineering - Energy and Aeronautics)
semester
1° Semester
Teaching materials

AIMS AND CONTENT

LEARNING OUTCOMES

The main components of a measuring chain are presented and discussed. Post-processing tools for statistical moment and time (frequency) dependent analysis are also provided. The basic laws governing the main fluid dynamic instrumentations (such as Hot-wire anemometry, Laser Doppler Velocimetry and Particle Image Velocimetry) are provided and discussed.

AIMS AND LEARNING OUTCOMES

The student should be able to:

- identify the proper probe for velocity and pressure fields investigation to be used, based on the specific definition of the quantities to be measured and in relation to the constrains regarding the accuracy, sensibility, spatial resolution and frequency response;

 - employ the different measuring techniques, setting the acquisition parameters for the inspection and analysis of three-dimensional unsteady flows of practical and industrial interest;

- provide a statistical analysis of an ensemble of data, as well as a detailed characterization of the dynamics of complex systems by means of advanced post-processing routines like the Fast Fourier Transform, the auto- and cross-correlation coefficients and phase-locked ensemble averaging;

- acquire expertize in the treatment of voltage signals as well as in the development of regression and calibration curves of complex systems.

The post-processing routines will be developed in Matlab.

Teaching methods

Frontal lessons will be mainly employed in the course. The basic rules describing the theory of the measurement chains, of signal analysis and the basic operating principles of the different probes introduced into the course will be provided to the student. Experimental activities will be also carried out in the Aerodynamics and Turbomachinery laboratory in order to provide to the student expertize in the setting and operation of the different probes presented in the course. Post-processing routines will be also developed in Matlab. It is strongly suggested the participation of the student to the lessons, since the examination is driven by arguments discussed and presented during the lessons 

SYLLABUS/CONTENT

Introduction to the main components of a measuring chain: transducers, filters, amplifiers and A/D conversion board. Nyquist’s theorem. Frequency response and dynamic calibration.

Data statistics. Errors due to finite number of samples and samples dispersion. Mean, rms and higher order statistical moments. Probability density function.

 

Introduction to the basic laws governing different kind of probes and possible applications.

 

Pneumatic probes (1,3, and 5 hole probes): static pressure taps, pressure transducers and directional calibration;

Fast response aerodynamic pressure probes (FRAPP): frequency response and dynamic calibration;

Hot-wire anemometry (HWA): King’s and Jorgensen’s laws;

Laser Doppler Velocimetry (LDV): introduction to the Doppler effect. Seeding particles and their dynamic;

Particle Image Velocimetry (PIV): cross-correlation and magnification ratio;

 

Advanced post-processing techniques: phase-locked analysis, Fourier’s transform, cross-correlation and autocorrelation functions. Applications with Matlab codes.

RECOMMENDED READING/BIBLIOGRAPHY

VKI lecture series, Measurement Thecniques in Fluid Dynamics

TEACHERS AND EXAM BOARD

Exam Board

DANIELE SIMONI (President)

DAVIDE LENGANI (President)

CARLO CRAVERO (President)

FRANCESCA SATTA

ANDREA CATTANEI

LESSONS

Teaching methods

Frontal lessons will be mainly employed in the course. The basic rules describing the theory of the measurement chains, of signal analysis and the basic operating principles of the different probes introduced into the course will be provided to the student. Experimental activities will be also carried out in the Aerodynamics and Turbomachinery laboratory in order to provide to the student expertize in the setting and operation of the different probes presented in the course. Post-processing routines will be also developed in Matlab. It is strongly suggested the participation of the student to the lessons, since the examination is driven by arguments discussed and presented during the lessons 

EXAMS

Exam description

The examination is composed of two parts. The first consists in the discussion of an exercise focused on the post-processing of different kind of data acquired by the research group of the professor, and provided to the student some days before the examination data. In the second part an oral discussion of theoretical topics treated in the lessons will conclude the examination. The examination data will be provided previous appointment.

Assessment methods

The oral examination will allow verifying the acquired knowledge of the student regarding the theory of the different measurement techniques, as well as the mathematical foundations of the different post processing algorithms. With the exercise the capability of the student in the development of a Matlab program aimed at the statistical and dynamical inspection of an ensemble of data will be verified.