3 days MOT/MOT1-E
- Engineers and technical staff of engine design, development or tuning departments, SI or Diesel.
- Applicants should be aware of engine components vocabulary.
- This course provides an up-to-date knowledge on the fundamentals about energy conversion and measurements in combustion engines.
- Upon completion of the course, participants will be able to understand:
- the basic parameters on how engines operate and on hydrocarbons characteristics,
- the main differences between SI and Diesel engines,
- the measurements conducted at the engine dyno and roller bench.
- It is recommended to fully master the contents of this module to attend the Module 2 “Spark Ignition Engines” - page 29, Modules 3 “Diesel Engines” - pages 31 and 32. It is also necessary to master the contents of these modules to attend Module 4 “Introduction to the engine control module” - page 64.
- Attendants should understand the main engine components and their functions.
Ways and means
- Many real examples.
- Short calculations on real case data.
Air pollution, roots & consequences, regulations 0.5 day
- Primary and secondary pollutants.
- Air quality: space (local or global) and time scales. Consequences and impacts.
- Phenomena: ozone layer, greenhouse effect, acid rains, photochemical smog, …
- Air quality standards, regulations applied to the car emissions and approval cycles.
- Regulated and non regulated pollutants (NRP).
How do engines work & basic parameters 1 day
- Combustion engines history.
- How do thermal piston engines work: 4-stroke and 2-stroke cycles, gasoline/Diesel, indirect/direct injection, naturally aspirated (NA)/supercharged (SC).
- Geometric parameters: conrod-crank system, bore, stroke, cubic inch displacement, compression volumetric ratio, cylinder spacing, conrod ratio lambda, timing diagram.
- Operating parameters
- Performances: torque (instantaneous, average), power, notion of load, use curve, cycle engine work, mean indicated pressure (IMEP), mean effective pressure (BMEP), friction mean pressure (FMEP), mean piston speed, thermal load and specific power.
- Combustion/emissions: air/fuel ratio, stoichiometry, stoichiometric quantity, equivalence ratio, excess air coefficient, exhaust gas specific emissions.
- Air loading: volumetric efficiency, volumetric performance.
- Efficiency: different efficiencies, differences between the theoretical cycle and the real cycle, specific fuel consumption (SFC), thermal balance.
Combustion - Comparison of SI & Diesel engines 0.5 day
- Combustion: combustion equation, determining the stoichiometric quantity and the air/fuel ratio, calorific value. Pollutants formation, flammability limit, auto-ignition delay.
- Comparison of SI and Diesel engines
- Combustion process: load control, preparing the air-fuel mixture, initiation, expansion, pollutants formation, exhaust gas recirculation (EGR), vibrations and noise origins.
- Full load performance limits: knocking, mechanics, thermo-mechanics, exhaust temperatures.
- In-use efficiency: downsizing, downspeeding.
- Exhaust gas after-treatment.
- Case of the gasoline direct injection (GDI).
Engine fuels 0.25 day
- Situation, market, restrictions and adaptations of oil products due to the motor vehicle fleet changes, biofuels.
- Hydrocarbons structure and properties: alkanes, alkenes, aromatics, naphthenes, H/C ratio, crude structures, main characteristics expected to meet SI and Diesel engines’ needs (volatility, octane and cetane ratings, cold engine operability, sulfur content).
Testing methodology - Measurements on engines & exhaust gas analysis 0.75 day
- Pressure, ionization and temperature sensors. Sampling probes.
- Angular synchronization.
- Interpreting the results.
- Measurements of exhaust emissions and evaporation losses.
- Gas analyzers. Opacity meters.
- Evolution of analysis materials: trends and developments.