ADVANCED MEASUREMENT METHODS (5 CFU)
The course will be offered in English and starts on March 2017 (1 day per week, 8 weeks).
Co-ordinator: Fabio Cozzi, Department of Energy, Politecnico di Milano
The aim of the course is to provide PhD students with general concepts and updated information on advanced experimental methods relevant to the development of conventional and nuclear power systems. The course program will cover applications related to the measurement of thermo-fluid-mechanic quantities, under both steady and unsteady regimes, with single phase or two-phase flows, turbulent and reactive conditions.
The course is divided in five modules as follows:
1. Introduction to Measurement Methods and Temperature measurement. (5 hours) Prof. Antonio Salerno
Error analysis of experimental data; frequency analysis, transfer function, Fourier transform (FFT). Temperature measurement: general principles; classical temperature probes (thermocouples, resistance thermometers, thermistors); static and dynamic calibrations; use in complex environment (high temperature reactive flows or high speed flows). Temperature measurement by radiative methods: principle and application of infrared thermography, optical pyrometers and noncontact techniques.
2. Measurement of thermal fields by optical techniques. (5 hours) Prof. Andrea Lucchini
The nature of light, visible and IR spectrum, propagation of light, refractive index and Snell’s law of refraction. Lenses and Simple Optical Systems, Spectrometers. Diffraction, Diffraction Limited Imaging , Depth of field, magnification. Principles of Interference, Shadowgraph and Schlieren Methods. Measurements of thermal fields in transparent media by optical techniques.
3. Flow measurement by optical techniques. (5 hours) Prof. Fabio Cozzi
Flow visualization through laser beams and laser sheets. Photodetection: photomultipliers, Cameras (CCD, MOS,..). Light sources: thermal, laser, diodes.
Quantitative flow measurements by LDV and PIV: theory and applications.
Quantitative flow visualization by Background Oriented Schlieren technique
4. Flow measurement by probes. (5 hours) Prof. Giacomo Persico
Directional pressure probes and hot wire anemometry for steady and unsteady flow measurements.
5. Two-phase flows. (5 hours) Prof. Manfredo Guilizzoni
Fundamental equations and governing parameters, averaged models. Measurement of void fraction (local, multi-local, spatially-averaged), optical probes, impedance probes, problems of temperature measurement in two-phase flows, temperature measurement using combined local probe, thermocouple devices.
Note: The students will be requested to perform at least one laboratory experience with the supervision of one of the teachers, and to prepare a report on the subject, which will be discussed during the oral examination.