Today, supercharging means a key technology for the development of internal combustion engines. The objects are to enhance effective power by increasing mean effective pressure, to improve dynamic behaviour as well as specific fuel consumption and to comply with lawful emission standards.
Reducing the number of cylinders and the total engine displacement, downsizing along with increased boost pressure leads to a higher mean effective pressure. As a result, the efficiency is improved, but the peak pressure and heat flow rate are increased. This causes a higher thermo-mechanical load of the engine components. Improving the dynamic behaviour by adjustment devices or by switching turbochargers leads to an enlargement of negative gas exchange work and consequently to a loss of efficiency. High pressure exhaust gas recirculation that is applied to reduce NOx emission also increases the gas exchange work. Downsizing of a spark ignition engine makes the engine operate closer to the knock limit and the turbocharger operate closer to the surge line. Keeping the limit of exhaust gas temperature for thermo-mechanical purposes causes a higher fuel consumption, since in customers’ driving operation the rate of full load rises. The reduction of CO2 emission means the biggest challenge for the engine development in the future, especially since exhaust gas emissions are being limited simultaneously more and more and since new test methods (world harmonized light vehicles test procedure, portable emissions measurement system) intensify the requirements.
The demand for a higher efficiency of commercial vehicle engines as well as low and medium speed diesel engines rises permanently. That matter of fact and compliance with NOx emission limits goes along with a very high pressure ratio and defines the supercharging concept for this reason. Gas engines will gain in importance in all fields of application.
Optimizing the supercharging of combustion engines requires a detailed knowledge about the behaviour of the complete system. The operating performance can be predicted very well with simulation models. 3D computational fluid dynamics is an important tool for optimizing the intake area. Real time models are used to control the system. The complete system is tested on a highly dynamic engine test stand. Model-based control is here optimized by bypass structures.
At the 18th SUPERCHARGING CONFERENCE on 12th/13th September 2013 in Dresden the most current methods and results of development will be presented. Engine developing engineers and manufacturers of supercharging systems and other important components will contribute their part. The diversity of engines will reach from car engines up to low speed two-cycle ship engines. The conference will be held in German and English supported by simultaneous translation. As a specialist conference the 18th SUPERCHARGING CONFERENCE represents a forum for all those who work on the development of supercharged combustion engines.