Tecnologia de Motores de Combustão

Knowledge in Thermodynamics, Fluid Mechanics and Heat Transfer.

In theoretical classes, a theoretical presentation of each subject is given.
In theoretical-practical classes, theoretical-practical exercises are solved

» To understand, in theoretical and practical terms, the operating mode and technologies of internal combustion engines;
» To understand the design processes of the main components and the manufacturing technologies of engines;
» To formulate and solve exercises to analyse the operation and performance of engines.

INTRODUCTION TO THE STUDY OF HEAT ENGINES: Fundamental concepts; Classification of reciprocating engines; Speed ​​and load of the reciprocating engine.
THEORETICAL AND REAL CYCLES. PRESSURE DIAGRAMS: Thermal efficiency and average pressure of the cycles; Indicated cycle and average indicated pressure; Difference between real and theoretical cycles; Pressure diagram inside the cylinder as a function of the angular displacement of the crankshaft for 2 and 4 stroke engines.
FUEL, MIXTURE AND COMBUSTION: Types and properties of fuels; Composition and formation of the mixture; Stoichiometric ratio; Heat released during combustion; Start of combustion.
CHARACTERISTIC CURVES AND HEAT BALANCE: Indicated, effective or brake power and absorbed power. Average effective pressure. Efficiency. Heat balance. Specific consumption of SI and CI engines. Stability in engine operation. Regulation and regulators.
MAIN COMPONENTS OF AN ENGINE, FUNCTION AND MATERIALS USED IN MANUFACTURING: Block and Cylinders; Head; Gasket between block and head; Combustion chamber; Valve guides and seats, Clearance between guides and valves and sealing gaskets for valve guides; Pistons and rings; Piston pin; Connecting rod and crankshaft; Crankshaft supports; Bearings; Crankshaft and connecting rod bearings;
KINEMATICS AND DYNAMICS OF ALTERNATIVE ENGINES, DISTRIBUTION: Diagram and types of distribution; Camshaft control; Valves: Valve dimensions and stroke. Variation in lift during movement; Effect of alternating inertia forces. Valve temperature with the engine running. Materials used in the manufacture of valves; Sodium valves; Taps, tappets or impellers; Clearances between valves and “touches”; Automatic clearance adjustment “touches”; Automatic actuators; Valve recall springs; Timing adjustment.
EXHAUST GAS RECIRCULATION SYSTEM (EGR): Function, structure and operation of the system. Valve cooling types and systems.
INTERMEDIATE COOLER OR “INTER-COOLER”: Fundamentals, structure and operation.
SOLVING THEORETICAL-PRACTICAL EXERCISES.

In this unit, the periodic assessment methodology is applied, with the following characteristics:
1) Final exam.
2) 2 tests, for which access requires a minimum of 75% attendance in the contact hours (T+TP), already elapsed on the date of the test.
3) In the exams, each written exam will have a maximum duration of 2 hours.
4) The student's approval without taking a final exam is subject to compliance with the following requirements:
4.1) Attendance at least 75% of the total hours of the curricular unit;
4.2) Minimum average of 9.5 points in the grades of the 2 tests;
4.3) A minimum of 8 points in the classifications of each of the 2 tests;
6) The approval of students who take the final exam is subject to obtaining a minimum of 9.5 points.
7) Both final exams and tests will be worth 20 points. In this quotation, the theoretical component contributes with a quotation of 13.5 points and the theoretical-practical component with 6.5 points.

NOTE:
The use of consultation elements or electronic devices, or others, is not permitted during the tests/exams.

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