• Motori SUS, Semester 1, position 2

The aims of the course are to provide a comprehensive insight into the subject matter of Engine Fueling and Mixture formation in IC Engines. Broadening existing and acquiring new knowledge in hydrodynamics by studying spray and droplet formation and break-up. Broadening knowledge on geometric and process parameters influencing the quality of air-fuel mixture. Understanding the influence of air-fuel mixture time-space characteristics on engine combustion process dynamics and performance. Acquiring skills in calculating and simulating characteristics of fuel spray and droplet in time, angle and space domain.

Students are capable of performing calculation of spray formation and break-up, primary and secondary fuel droplet break-up for given injection system parameters in terms of high pressure pump, fuel line and injector. Students are capable to determine fuel droplet SMD (Sauter Mean Diameter) and time required for droplet evaporation for thermodynamic parameters during engine cycle.

1. Engine requirements in terms of air-fuel mixture strength. Air-fuel mixture characterization - homogeneous, stratified and heterogeneous mixture. Air-mixture strength and characteristics influence on combustion process. 2. Fuel spraying - basic approach. Fuel surface tension, viscosity and density. Reynolds, Weber and Ohnesorge numbers. 3. Gasoline engine mixture formation systems. Carburetor, fuel and air flow characteristics. Carburetor auxiliary systems. Low-pressure fuel injection, Manifold/Port Fuel Injection (MPI/PFI) Systems. High-pressure Direct Injection Systems (DI) with side injector (DIS) and central injector (DIC). Multi-injector systems. 4. Diesel fuel injection systems. Direct and indirect injection, high-pressure injection pumps. Injectors and nozzles. Fuel delivery and injection dynamics. Electronic Control Unit. 5. Spray formation. Spray characteristics - shape, angle and length. Spray analysis using Reynolds, Weber and Ohnesorge numbers. Spray break-up. Droplet formation. Primary and secondary droplet break-up. Spray and droplet break-up calculation and simulation methods. Sauter Mean Diameter (SMD). 6. Fuel droplet evaporation. Droplet evaporation simulation methods.

а) Auditory exercises: 1. Display and analysis of Carburetor based Engine fueling. Carburetor Design and Calculation. 2. Display and analysis of SI Engines Fuel Injection Systems. Engine Sensors. Fuel Injector rated flow characteristics. Numeric examples for injection time determination. Injection time correction. Generation of basic Engine Injection Map. 3. Diesel Fuel Injection Systems – numerical examples for HPP element & cam lobe design. 4. Fuel spray formation and break-up calculation and simulation methods. Fuel droplet break-up calculation and simulation methods. Sauter Mean Diameter calculation. b) Laboratory exercises: Testing SI Engines Fuel Injection System components: Injector fuel rate determination (stationary, dynamic), Fuel Rail Dynamic Pressure measurement and analysis, Mass Air Flow-meter (MAFM) Characteristics measurement. Measurement and comparative analysis of MAFM and MAP sensor dynamics. Measurement & Analysis of Ignition System Dynamics.

Desirable: Good practical knowledge of Matlab/Simulink

1. М. Тomić: IC Engines Fueling and Ignition Systems (in Serbian), Uni. of Belgrade, Faculty of Mechanical Engineering, Belgrade, ISBN 978-86-7083-769-0, 2012. 2. S. Popović: Extracts from Lectures (handouts), available in digital form 3. IC Engine testing Laboratory (with an engine on the test bed) 4. Flow Test Bench (in accordance to ISO 5167) 5. Diesel Injection System test Bench 6. DAQ System: National Instruments PXI-1042-RT8186/5401/6123/6229/4070/6602/8461 7. National Instruments LabView

Total assigned hours: 75

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

Auditory exercises: 11
Laboratory exercises: 14
Calculation tasks: 5
Seminar paper: 0
Project: 0
Consultations: 0
Discussion/workshop: 0
Research study work: 0

Review and grading of calculation tasks: 0
Review and grading of lab reports: 4
Review and grading of seminar papers: 0
Review and grading of the project: 0
Test: 0
Test: 6
Final exam: 5

Activity during lectures: 0
Test/test: 25
Laboratory practice: 35
Calculation tasks: 0
Seminar paper: 0
Project: 0
Final exam: 40
Requirement for taking the exam (required number of points): 30

J. Heywood: Internal Combustion Engine Fundamentals, McGraw Hill, ISBN-13: 978-1260116106, 2018; G. Stiesch: Modeling Engine Spray and Combustion Processes, Springer-Verlag Berlin Heidelberg, ISBN 978-3-540-00682-4, 2003; C. Baumgarten: Mixture Formation in Internal Combustion Engines, Springer-Verlag Berlin Heidelberg, ISBN 978-3-540-30835-5, 2006; H. Zhao: Advanced direct injection combustion engine technologies and development Vol.1 i 2, Woodhead Publishing, ISBN 978-1-84569-732-7, 2010; C. Arcoumanis, T. Kamimoto: Flow and Combustion in Reciprocating Engines, Springer-Verlag Berlin Heidelberg, ISBN: 978-3-540-64142-1, 2009