The diesel engine is still the benchmark for efficiency among internal combustion engines. However, more and more complex systems are needed to purify the exhaust gas from harmful components. In the last few years we have dealt intensively with this complex topic at FVT.

Despite all advancements in the combustion process, strict emissions legislation in Europe requires a complete exhaust after-treatment system (AGN) for car and truck engines. Complete means in this case that for each of the legally limited pollutant components an aftertreatment system for the reduction is present. These are typically an oxidation catalyst (DOC) for hydrocarbons (HC) and carbon monoxide (CO), a particulate filter (DPF) and a lean NO_x trap (LNT) or selective catalyst (SCR) for nitrogen oxides (NO_x). 

In addition to their basic functions, the various components also perform auxiliary functions through which they sometimes interact strongly. Thermal management is an integral part of research into AGN systems as the various catalysts require a specific operating temperature. All in all, the development of such systems is a challenging task. FVT research focuses on AGN.

FVT focuses on applied research on AGN systems, and this is mainly done on the engine test bench. The measurements require the massive use of complex exhaust gas measurement technology and a high degree of automation to ensure consistent boundary conditions. For the most part transient load cycles have to be measured, as the cold start phase has a dominant share in the emission result. The measurements are correspondingly lengthy and difficult. In the FVT, many test benches are equipped with the required measuring technology.

The simulation has strong supportive character in research on AGN. Essential content, which is treated mathematically, is the warm-up after the cold start (thermal management). The subject of thermal management goes far beyond the scope of the actual AGN and covers virtually all parts of the powertrain, such as engine process and hybridization. Here, the simulation, in particular the simulation of the entire system, can make a substantial contribution. In addition to thermodynamics, the reaction kinetics is mapped in the simulation. The combination of both approaches allows a large number of further investigations, which are difficult to carry out on the test bench. Simulation and measurement interact strongly.

The FVT uses commercial and custom tools for the simulation.