CODE 56624 ACADEMIC YEAR 2021/2022 CREDITS 6 cfu anno 1 INGEGNERIA MECCANICA - PROGETTAZIONE E PRODUZIONE 9269 (LM-33) - GENOVA SCIENTIFIC DISCIPLINARY SECTOR ING-IND/08 LANGUAGE Italian TEACHING LOCATION GENOVA SEMESTER 2° Semester MODULES Questo insegnamento è un modulo di: HEAT TRANSFER AND FLUID MACHINERY TEACHING MATERIALS AULAWEB OVERVIEW The course is aimed at providing the basic information for: The choice of a fluid machine basing on the requested performance The knowledge of its behaviour, and related fluid dynamic and structural issues AIMS AND CONTENT LEARNING OUTCOMES The course aims at providing the basic information for: The knowledge of pumps and compressors architecture, and related fluid dynamic, structural, and economical issues. The knowledge of the machine behavior. The choice, the installation, and the operation of the machine. AIMS AND LEARNING OUTCOMES By means of active attendance of classes and individual study, the student will gain: An operative knowledge of: the physical properties of the commonly processed fluids, the followed thermodynamic transformations, the balance equations employed for studying the flow, the similarity theory and the statistical approach, and the effect of the main aerodynamic and structural constraints on the blade design. A basic knowledge of the effect of the density variation on ducts and fluid machinery operation. With reference to turbomachine (fans, multistage compressors, and pumps), a basic knowledge of: the machine architecture, the features of the various parts, the variation of fundamental fluid dynamic and thermodynamic quantities along the machine, and the characteristic curve. A basic knowledge of the effect of aerodynamic and structural constraints on a turbomachine design. A basic knowledge of anomalous operation of pumps and compressors. With reference to positive displacement pumps and compressors, a basic knowledge of the functioning and of the causes of deviation from the ideal behavior. PREREQUISITES Basic knowledge of Fluid Dynamics, Thermodynamics, and Fluid Machinery. TEACHING METHODS Theoretical and applied classes. SYLLABUS/CONTENT 1. Basic concepts of fluid machinery Fluid Dynamics and Thermodynamics 1.1. The typical engineering problems (direct, design, and choice ones). The main properties of the technical fluids. The state equation and the main thermodynamic relations. The basic equations for the study of open and closed systems and turbomachines and positive displacement ones (continuity, momentum, energy, Euler); definitions of the important quantities for the study of fluid machinery (head, efficiency, specific work). 1.2. The similarity theory: choice of the reference dimensional parameters, main non-dimensional parameters for turbomachines (pumps, fans, compressors). Relation between the similarity theory and the statistical approach; choice of the kind of machine for given performance: the Cordier plot. 2. Typical applications of the balance equations Effect of Mach number and density variation on: the work input, the shape of a nozzle, and the heat transfer in a duct; adiabatic, polytropic and isothermal efficiency; thrust of moving fluids on duct walls, boundary layer separation and airfoil lift and drag. Overall efficiency and energy cascade for a fan. 3. Turbomachines (compressors, blowers, fans, and pumps, of axial and radial type) 3.1. Typical architecture and functioning principle, blade shape, analogy with an isolated airfoil, relation between blade angle and characteristic curve, flow deviation at the blade outlet and slip effect in centrifugal rotors, typical applications. Mechanical strain on blades, rotors, stators, shaft and shroud. Effect of centrifugal force and aerodynamic thrust on the blade. Limitations of the operation: stall and surge in compressors; pumps cavitation, suction height and ways of avoiding them. 3.2. Similarity and characteristics curves of turbomachines and of typical fluid dynamic loadings (hydraulic circuits and choked nozzles). Determination of the operating point: matching of the characteristic curves for compressible and incompressible flow. 4. Positive displacement machines 4.1. Reciprocating and rotary screw/vane compressors and pumps: functioning principle, effect of the valves kind, characteristic curves, and typical applications. RECOMMENDED READING/BIBLIOGRAPHY Course notes by the lecturer. L. A. Catalano, M. Napolitano, Elementi di Macchine operatrici a fluido, Pitagora Editrice. R.I. Lewis, Turbomachinery performance analysis, John Wiley and Sons. TEACHERS AND EXAM BOARD ANDREA CATTANEI Ricevimento: Please contact the teacher by e-mail at the address <Andrea.Cattanei@unige.it> Exam Board ANDREA CATTANEI (President) EDWARD CANEPA CARLO CRAVERO FRANCESCO DEVIA GUGLIELMO LOMONACO LUCA ANTONIO TAGLIAFICO VINCENZO BIANCO (President Substitute) LESSONS LESSONS START https://corsi.unige.it/9269/p/studenti-orario Class schedule FLUID MACHINERY EXAMS EXAM DESCRIPTION Oral exam at the end of the course, normally every Tuesday. Please contact the lecturer at Andrea.Cattanei@unige.it at least one week in advance. ASSESSMENT METHODS General discussion of the treated topics based on two questions. The exam aims at ascertain comprehension of physical meaning and engineering interest. Exam schedule Data appello Orario Luogo Degree type Note 18/02/2022 09:00 GENOVA Esame su appuntamento 16/09/2022 09:00 GENOVA Esame su appuntamento FURTHER INFORMATION Pre-requisites : Basic knowledge of Fluid mechanics, Thermodynamics and Fluid machinery.
