About The Project
The automotive industry is predominantly being driven by emission legislations which enforce manufacturers to reduce fuel consumption and exhaust emissions. The legislation has led to the introduction of downsized engines incorporating turbochargers to compensate for the reduction in power, alongside new technologies such as cylinder deactivation and light weight powertrains.
Although this strategy has been successful in achieving lower engine emissions, on the other hand it has affected the vehicle’s Noise, Vibration and Harshness (NVH) characteristics. As downsized engines have higher combustion pressures, the resultant torsional oscillations are more broadband and severe than in traditional internal combustion engines. Palliative devices, such as clutch pre-dampers or the Dual Mass Flywheel (DMF) are used to mitigate the torsional oscillations generated in automotive powertrains. However, these palliatives can add considerable mass/inertia and are only effective over a limited frequency ranges.
A different approach that can potentially achieve vibration reduction over a broader band of frequencies is the Targeted Energy Transfer (TET) method. TET uses nonlinear absorbers, also called as Nonlinear Energy Sink (NES). The NES either dissipates more efficiently the vibrating energy through modal structural damping or by directing this energy (in a nearly irreversible manner) from a source (primary system) to the NES. The NES is characterized by inherently nonlinear stiffness characteristics, which is fundamental in achieving TET conditions.
The Dynamics Research Group in the Wolfson School of Mechanical, Electrical and Manufacturing Engineering performs computational and experimental studies on automotive powertrain systems in order to design efficient NES absorbers that are capable of reducing the amplitude of torsional oscillations that are generated in automotive drivetrains. In addition, we are exploring ways to efficiently convert the kinetic energy attracted to the NES into electrical energy. This energy will be used to power low-energy consumption sensors in automotive remote/wireless applications.