CD Laboratory for Thermodynamics of Reciprocating Engines

Analysing and modelling the position of reciprocating engines on the basis of thermodynamics is the focus of research activities. In particular, piston compressors and two-stroke engines are analysed.

The available simulation methods and analysis procedures for compressors and two-stroke engines do not always meet today's requirements. Work is being carried out on optimising or redeveloping these technologies using applied thermodynamics, with a particular focus on refrigerant compressors for refrigerators and high-speed two-stroke engines. Both are produced in large quantities worldwide and even a slight optimisation of their performance will enable major energy savings.

A qualitatively and quantitatively high-quality representation of the working processes of these piston engines is being developed, allowing their performance to be optimised. In addition, improved methods for describing the charge exchange, i.e. the exchange of combustion gases in the cylinder, are also being researched. In both types of reciprocating engines, the flows associated with the charge exchange generate strong pressure fluctuations, which subsequently reduce the efficiency of the engines.

Due to the lack of good simulation methods and analysis procedures to describe these processes, numerical methods are being adapted to new and improved modelling approaches. To this end, so-called 0 D, 1 D and 3 D methods are being further developed and - where necessary - combined with each other. In the 0 D simulation, no spatial changes are taken into account, only temporal changes. In addition to the thermal behaviour of a piston engine, it also makes it possible to describe the behaviour of the powertrain, the fuel supply and the exhaust system. In the 1 D simulation, changes in one spatial direction are considered and the water, oil and air sides of the engine function are described. Changes in all three spatial directions (3 D) are used to describe radiator and engine compartment flows.

Overall, the further development and combination of these methods based on thermodynamics will make it possible to improve engine design and engine production.