• Hidroenergetika, Semester 2, position 3

Mastering knowledge of engineering applications of fans and turbocompressors as machines for raising of fluid energy. Capacity to work in practice on energy installations, as well as design of installations that include a fan or turbocompressor as built-in element with its function.

Upon successful completion of this course, students should be able to: 1. identify and describe the various types and constructions of the fans and turbocompressors, the principles of their work, as well as the standard way of their installation, 2. determine the duty points of the ventilation system and fan, 3. select the appropriate fan and the most energy efficient way of its regulation, 4. determine the duty point of the fan by using the dimensionless parameters (characteristic coefficients), 5. calculate the fan characteristics when working with other fluid density, 6. calculate the thermodynamic and energy parameters of the turbocompressor, 7. design and develop (with the help of CNC and 3D printers) the 3D model of multistage axial compressor, with special emphasis on the impeller blades and guide vanes.

Task and constructions of fans. Examples of application. Similarity theory, dimensionless parameters and fans classification. The calculation of basic dimensions of the fan – type, impeller diameter, impeller outlet width, spiral casing. Matching and regulation of fans. Testings of fans. Specifics of fan and fan systems. In built characteristics of fans. Axial fans without stay vanes - a characteristic of the fan, its matching. Turbulent swirl flow phenomenon in pipes and jets. Air curtains, reversible fans, fans for fire conditions, ceiling and roof fans, fans in cooling systems. Fan selection. Fans in building energy certification. Building air leakage test ("blower door" test). Noise levels of a fan and fan installation. Thermal machines classification. Task and constructions of turbocompressors. Energy balance. Thermodynamic basis. Efficiency. Uncooled and cooled turbocompressors. The exchange of energy in the axial grid. Multistage compressors. Typical performance curves of axial turbocompressors and behavior in work (choke and surge limits). Determination of optimal characteristic coefficients of centrifugal compressors. Performance curves of centrifugal compressors and their behavior at work.

1. Auditory exercises: Calculation examples of lectured material: Matching and regulation of fans. Fan selection. Thermodynamic analysis. Efficiency determination for cooled and uncooled turbocompressors. Multistage turbocompressors. 2. Project design: 2.1. Presentation of the manual for multistage axial compressor design: from calculation of basic dimensions to 3D model. 2.2. Introduction to the application of the existing softwares for turbocompressor design. 3. Laboratory exercises: 3.1. Demonstration: Laboratory for hydraulic machines - constructions of fans and turbocompressors and description. 3.2. Active laboratory exercises: 1.Testing of the fan performance curves. 2.Determination of sound power levels of noise sources (fan) using sound pressure. 3.Fan electrical motors and regulators wiring and starting the machines.

Completed courses: Fluid Mechanics B and Thermodynamics B.

1. Textbooks listed in the references and list of literature provided for students. 2. Lectures and exercises handouts. 3. Manual for multistage axial turbocompressor design. 4. Laboratory for hydraulic machines - fans and turbocompressors, installations, measuring equipment.

Total assigned hours: 75

New material: 20
Elaboration and examples (recapitulation): 10

Auditory exercises: 12
Laboratory exercises: 5
Calculation tasks: 5
Seminar paper: 0
Project: 8
Consultations: 0
Discussion/workshop: 0
Research study work: 0

Review and grading of calculation tasks: 0
Review and grading of lab reports: 0
Review and grading of seminar papers: 0
Review and grading of the project: 5
Test: 5
Test: 0
Final exam: 5

Activity during lectures: 0
Test/test: 50
Laboratory practice: 5
Calculation tasks: 0
Seminar paper: 0
Project: 15
Final exam: 30
Requirement for taking the exam (required number of points): 21

Genić S.,Stamenić M.,Živković B.,Čantrak Đ.,Nikolić A.,Brdarević Lj. (2017):Manual for energy managers' training in the industry energetics,Fac. of Mech. Eng.,University of Belgrade,Belgrade (in Serb); Protić Z., Nedeljković М. (2021): Pumps and fans, Problems, solutions, theory, 7th edition, Faculty of Mechanical Engineering, Belgrade (in Serbian); Obradović N. (1974): Turbocompressors, Faculty of Mechanical Engineering University of Belgrade, Belgrade. (in Serbian); Ilić D. B., Čantrak Đ. S. (2017): Manual for fluid flow measurements in laboratory, Fac. of Mechanical Eng. Univ. of Belgrade, Belgrade. (in Serbian); Čantrak Đ.S.(2022):Investigation of the Turbulent Rankine Vortex in Pipe behind Axial Fan Impeller Using Optical (PIV and LDA) Measurement Methods and Visualization,NTI,Vol.59,No.1,MTI,Belgrade,(Serb)