With the increasing demands of motorists regarding comfort inside cars and the more stringent legal framework conditions for vehicle noise emissions, the requirements placed on engine acoustics have also become stricter. After all, the engine has a significant influence on driving noise alongside wind and rolling noise. Measures for reducing fuel consumption such as turbocharging, downsizing, lightweight construction and new combustion processes can exacerbate this: they can lead to increased vibrations and oscillations, influencing both the acoustics and the dynamics of the engine. Therefore, the researchers and developers of this planning group focus on the question as to how efficient driving and pleasant engine acoustics can be brought into harmony.
Furthermore, the FVV engineers are investigating how the dynamics of highly efficient combustion engines can be optimised still further by examining all the mechanical components of a combustion engine that influence the torque on the crankshaft and therefore the drive behaviour.
Alongside calculations and simulations on a computer, the work performed on the test bench is especially important when researching engine acoustics and dynamics. The specific fields of research tackled by the planning group include the acoustic design of exhaust gas turbochargers, modelling the damping properties of operating fluids or the dynamics of valve and timing gears.
The electrification/hybridisation of the powertrain presents additional challenges for the developers of engine acoustics and dynamics.
To reliably predict interactions between acoustic and vibration phenomena of complex powertrain systems in an early development phase, appropriate test and simulation procedures are indispensable. The Research Association for Internal Combustion Engines (FVV) lays the groundwork for this with numerous projects which range from the detailed analysis of single engine components to automated processes for engine noise and transfer path analysis into the vehicle interior.Read more
Vibrations in the piston conrod lead to unwanted noise in modern combustion engines with self-ignition. The diesel knock or rattle is the best-known example. The aim of this project was to identify the causes of noise and to derive measures to prevent it. To this aim, numerous metrological investigations were carried out to stimulate the crankcases over the piston swing as well as to stimulate and transfer combustion noise over the piston con-rod. The newly developed simulation model formed the contact forces and the component vibrations in the crank drive and in the piston/cylinder contact and also considered transient thermal conditions. With the help of this model, the causes for noise could be identified and the effect of constructive alternatives determined. In addition, the simulation tool was used for elasto-hydrodynamic coupled multi-body systems.Read more
Projects of Planning Group 5 »Engine Dynamics & Acoustics«
Research Association for Combustion Engines eV
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