Simulation based optimization of the NVH characteristics in modern high speed engine during development phase

Engine noise mitigation is paramount in powertrain development for enhanced performance and occupant comfort. Identifying NVH problems at the prototype stage leads to costly and time-consuming redesigns and modifications, potentially delaying the product launch. NVH simulations facilitate identification of noise and vibration sources, informing design modifications prior to physical prototyping. Early detection and resolution of NVH problems through simulation can significantly shorten the overall development cycle and multiple physical prototypes and costly redesigns. During NVH simulations, predicting and optimizing valvetrain and timing drive noise necessitates transfer of bearing, valve spring, and contact forces to NVH simulation models. Traditional simulations, involved continuous force data export and NVH model evaluation for each design variant, pose efficiency challenges. In this paper, an approach for preliminary assessment of dB level reductions across design iterations is explained using 1/3 octave band frequency analysis of forces acting on various locations. Timing drive simulation for high-speed engine is simulated with different backlash values (baseline and reduced) for gear connecting the camshafts. With the reduced backlash resultant bearing forces reduced on both exhaust and intake camshaft. Converting these forces into different frequency bands using 1/3 octave band frequency analysis reveals significant dB level reductions within several frequency ranges. For exhaust camshaft bearings, noise reductions ranged from in the low-to-mid frequency spectrum. Furthermore, reduction in noise levels was observed for both exhaust and intake camshaft bearings in higher frequency range. Simulation outcomes demonstrably indicate a significant attenuation of dB levels within critical acoustic frequency bands. These findings underscore the potential of this streamlined approach to enhance efficiency of early-stage engine development by minimizing the need for extensive iterative prototype testing. Enabling expedited design optimization for improved NVH performance and aligning with the stringent NVH requirements for high-speed engine of every class