Simulating quiet and comfortable road travel
Computer-aided engineering (CAE) tools have become standard fare for virtual prototyping in order to reduce time and cost of development. They are particularly useful for multi-attribute design considerations, such as when optimal design for noise and vibration reduction conflicts with optimal design for reduction of weight and carbon dioxide (CO2) emissions. Well established deterministic CAE tools exist to model low-frequency (LF) noise and vibrations, and some energy-based (stochastic or probabilistic) high-frequency (HF) methods are also available. In order to fill the mid-frequency (MF) modelling gap, scientists initiated the EU-funded project MID-MOD. During the first reporting period, scientists evaluated five deterministic (typically used for LF) and five probabilistic (typically used for HF) methodologies currently at the laboratory stage for their potential applicability to the MF vibration range problem in industry. Models are being assessed for their ability to adequately represent component, subsystem and full vehicle scenarios in both interior and exterior noise generation. Model formulations and validation are ongoing. Application scenarios for the evaluation of interior and exterior acoustic truck issues have been defined. The latter will evaluate acoustic radiation and emission in the MF range of a truck silencer using a chosen deterministic theoretical method that will be validated with experimental results. Experimental measurements regarding internal car noise applications have commenced. The same deterministic method applied to the truck will be used to model acoustic radiation in the MF range from the signal horn. Component and subsystem levels have been defined for study of interior rail noise. Noise and vibration have important effects on consumer satisfaction and regulatory certification, translating to impact on the competitive position of the transport sector. MID-MOD is providing important CAE simulation tools that are currently lacking in order to reduce the time and cost of new product development while enhancing the overall performance of novel designs.