My Research
Internal Combustion Engine
The internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. This exothermic reaction creates gases at high temperature and pressure, which are permitted to expand. The defining feature of an internal combustion engine is that useful work is performed by the expanding hot gases acting directly to cause movement of solid parts of the engine, by acting on pistons, rotors, or even by pressing on and moving the entire engine itself.
Many researchers have made a research on the efficiency of the Gasoline engine and also Diesel engine. Both engines are the most popular and being used for today vehicle. However the efficiency of each engine still needs to be improved. Professor Helmut Eischlseder from Graze University of Technology had done lot of research to improve the efficiency of both engines. From his point of view, the most important limitation are the compression ratio and also the air & fuel ratio. If both of these can be controlled well, the analysis to get better engine efficiency would be easier.
For the current gasoline vehicle on the road today, averagely have only about 23.3% of efficiency. It is not even half of the source of energy that we are using. Some of the energy had losses to the mechanical losses, gas exchange losses, wall heat losses, losses due to real combustion and losses due to incomplete combustion.
The designs of engine combustion system keep changing yearly. Many inventions have been made. The latest Gasoline and Diesel Engine design have been change from ‘wall & air guided combustion system ‘to ‘spray guided combustion system’. This design has been applied to latest BMW cars which will give more efficiency compare to the previous design. From the spray guided concept, the fuel injector is being located exactly near the spark plug. From the analysis, the combustion will happen faster and have higher brake mean effective pressure (bmep). Professor Heikal from Engineering Research centre, University Brighton, United Kingdom is running his research into ICE (internal combustion engine). His experiment shows the higher pressure of injection spray also affect the combustion. He has done his research in the Sir Harry RICARDO lab towards the injection pressure. Most of the combustion occurs greater when it is about or higher than 160Mpa. This tells us the injection pressure is proportional to the combustion characteristic.
When comparing the SI (gasoline) and DI (Diesel) engine concept, the Diesel engine has slightly higher efficiency. The technology today has put Diesel into better fuel consumption and efficiency which averagely about 29.3% compare to SI engine only 23.3%. However, the concept of the Diesel engine today is combining with turbo charger; this is to make sure the engine have a higher inlet pressure to be compressed. If we realize, most of the German’s made cars today have divert their technology into Diesel technology. Mercedes-Benz, BMW and also Volks Wagen have put an effort in producing the Diesel cars with less emission rate and low fuel consumption.
The challenge right now to the researchers is to reduce the emission and increase the efficiency. Researchers keep studying in balancing these both criteria. Less emission rate is referring to SI (gasoline) engine while good efficiency is referring to DI (Diesel) engine.
Today, Daimler Chrysler is experimenting exhaust gas treatment for passenger cars. The exhaust system is containing oxidation catalyst, particulate filter SCR catalyst. The function is to reduce poisonous gas such as NOx and Soot. This new technology would be applied into latest Diesel production cars from Daimler Chrysler soon. By this new outcome, the production cars of Diesel engine might get good response worldwide.
Mohamed Faiz b Mohamed Amin
Mechanical Engineering (Automotive)
Universiti Teknologi PETRONAS
