LABORATORY FOR HYDRAULIC MEASUREMENT AND CONTROLS
Learning outcomes of the course unit
Knowledge and understanding:
At the end of this course the student should know, by means of lab experiments, some of the basics of the fluid mechanics. Moreover, he should gain understanding of the instruments and techniques adopted in measuring the main physical quantities in the field of hydraulics. Finally, the student, should be familiar with the errors and the problems encountered in measuring a physical quantity.
Applying knowledge and understanding:
The student should be able to analyze the experimental data collected during the lab experiments and to identify and classify the sources of errors on the basis of the used instrumentation. Finally, the student should be able to relate the lab results with the theory behind the experiments.
By the end of the course, the student should be able to evaluate, with critical mind, the experimental measurements of physical quantities in the fluid mechanics field.
The student should be able to clearly present the experimental results also by means of tables and charts.
Course contents summary
The course is structured in two parts: theory and lab experiments. The theory lectures cover the following subjects: Measurements of physical quantities, measurement system and dimensional analysis. Errors classification, probability distribution and propagation rules. Rules on writing measurements. Accuracy and precision of instruments. Static calibration of instruments. Operating principles of the instruments used in lab. The experimental activities are focused on the following subjects: Venturi meters. Hydraulic machines: pumps and/or turbines. Force of water jets. Weirs. Flow measurements in open channels. Rating curves of flood control systems.
Measurement systems and dimensional analysis. Introduction to error analysis – errors classification. Statistical distribution of accidental errors. Absolute error and relative error. Combination of component errors in overall system-accuracy calculations. Functional elements of a measuring instrument. Accuracy, precision and bias. Full scale, overload, threshold value, resolution and hysteresis. Repeatability and reproducibility. Meaning of static calibration. Least square regression. Laboratory experiences: calibration of a Venturi tube; measurement of the force exerted by a water jet on a surface; calibration of a Belanger weir; experimental determination of the characteristic curve of a centrifugal pump; theoretical and experimental study of a Pelton turbine; experiments on the physical model of a dam.
Misure e Controlli Idraulici (2006), Longo S., Petti M., McGraw-Hill Italia, Collana di Istruzione Scientifica, serie di Ambiente e Territorio.
Strumenti e metodi di misura (2004), Doebelin, E.O. , Mc Graw-Hill, 2004.
Introduzione all'analisi degli errori : lo studio delle incertezze nelle misure fisiche (2000), Taylor, J.R., Zanichelli.
Additional educational material available on the web site “elly.dicatea.unipr.it”: Lecture slides. Text of all the lab experiments.
Slides will be used to convey the most important messages of the theory lectures. The students will perform the experiments during the lab sessions. Before each experiment a lecture will introduce the objectives and the theoretical aspects of the studied phenomena. Then, the collected data will be analyzed (in groups of students) by means of computers and spreadsheets and a discussion of the results will follow.
Assessment methods and criteria
The examination is based on a written lab report and an oral exam. The examination is weighted as follows: 40% written lab report (proper analysis of the experimental data, clarity in presenting the results); 60% oral exam (theory questions, application of theory also to original problems and speaking ability).
Lecture attendance is highly recommended.