Norbert Zsiga, Anton Ledergerber, Nicolas Vuilliomenet 1 Introduction Engine Systems

1.Concept of a combustion engine 2.Different types of engines 3.Topics of the lecture «Engine Systems» 4.Tour through engine hallway ML E 2 Introduction Engine Systems

3 Open the hood…

4 Simplified model of a gasoline engine 44 Intake manifold Engine block Exhaust manifold

5 Simplified model of a gasoline engine 55 Throttle Intake manifold Engine block Exhaust manifold Ignition coil Fuel pump Injection Valves

6 Simplified model of an engine Throttle Intake manifold Engine block Exhaust manifold Ignition coil Fuel pump Injection Valves

7 Simplified model of a gasoline engine

8 Simplified model of gasoline engine

9 Questions: Which control actuators are minimally needed for a gasoline engine Why can the engineblock be intrepreted as a volumetric pump? Anwers: Throttle, Injector,ignition coil, valves,…. It pumps air form the low pressure intake manifold to the higher pressure exhaust manifold (exception: supercharged) Simplified model of gasoline engine

10 Mechanical System

11 4 Stroke Engine In this class only four stroke engines The four strokes: 1.Intake Stroke 2.Compression Stroke 3.Power Stroke 4.Exhaust Stroke =>Engine cycle consists of two revolutions

 Power Stroke and Compression Stroke are combined  Intake Stroke and Exhaust Stroke are combined, i.e. inflowing air washes out exhaust gas. => Engine cycle consists of one revolution 12 2 Stroke Engine

13 Gasoline & Diesel Engines Compression Ignition  CI Engine Spark Ignition  SI Engine Gasoline Diesel

14 Gasoline & Diesel Engines «Qualitative Control» «Quantitative Control» Gasoline Diesel Low power High power Low power High power

15 Questions: Is the combustion in a diesel engine stochiometric? (lambda=1) Is a throttle needed for a Diesel engine? What is the effect of pressing the gas pedal in a diesel and gasoline engine resprectively? Gasoline & Diesel Engines Anwers: No! There is always excess air No! The power is controlled by the amount of injected fuel Diesel: Inject more fuel Gasoline: Opening of throttle, more air into cylinder, controller injects then more fuel

16 Self Induction & Forced Induction Engines Air is sucked in by the down stroke of the cylindar which results in a pressure drop in the intake manifold Air is forced into the intake manifold by the charger Self induction/ naturally aspirated Forced induction/ super charged

17 Questions: Why does forced induction lead to higher specific power (W/kg)? Where is the power taken from for the compressor in forced induction? Anwers: For the same displacement volume ( Hubraum) = same weight, more fuel can be burned, more power is generated Turbocharger, energy from exhaust gas Mechanical, energy from engine shaft Self Induction & Forced Induction Engines

18 Information on the lecture Control of engine is in the focus (not thermodynamics and mechanics) Focus is on modelling only of the engine system Suitable lecture «Vehicle propulsion systems», focus on whole vehicle Good textbook/script is available Idle speed controller is developped and tested on real engine Oral exam in the end

19 ML E floor - «Tour de moteur»

Thank you for your attention. Let’s go!