NVH - Vehicle noise, vibration and harshness
The combined noise, vibration, and harshness - NVH - are immediately apparent when car drivers assess the ‘feel’ of a vehicle. In this article, we examine what NVH means to automotive manufacturers and customers, and how NVH simulation enables test engineers to optimize vehicle noise, vibration, and harshness.
A car that rattles or a motorbike that vibrates are tiring and annoying to use. For customers taking a test drive, the combined noise, vibration and harshness (NVH) is immediately apparent when they assess the ‘feel’ of the car NVH characteristics are high among the factors we use to judge the vehicle’s quality.
On longer journeys, the comfort of good NVH is one of the strongest brand differentiators. So good NVH performance is a necessity for luxury vehicles; while for others, any edges they can gain over competitors will pay back handsomely in brand equity and loyalty.
Optimizing Noise and Vibration
Vibration energy from an engine travels through the engine mounts, into the structure, and through the car seat into the driver. But energy from the same source can take a similar path through the structure to become acoustic noise when it is amplified by the cabin.
Optimizing these factors is therefore of utmost importance for the overall experience of the vehicle.
Computer-Aided Engineering (CAE)
CAE and test departments alike must endeavour to deliver a smooth, quiet vehicle. This is true no matter what the project – from a standard model iteration to developing a new, cutting-edge vehicle design with relatively untried, innovative propulsion, such as hybrid electric powertrains. Moreover, designers have their hands tied by emissions restrictions and face ever-shortening development time frames.
Brüel & Kjær offers tools to provide insight into NVH processes and break sounds down into their component sources and the paths they take. This is true for both the NVH test engineer and CAE analysis alike. And we bridge the gulf between them by auditioning NVH with highly authentic simulators throughout development.
NVH simulation enables managers and customers alike to ‘drive’ rival vehicles and previous models in highly realistic scenarios so engineers can quantify their opinions.
NVH product development has transitioned from paper-and-pen drafted designs to a computer-aided drafting (CAD) environment. This enables CAE Simulation for earlier vehicle testing and faster, less costly redesign.
Source Path Contribution - SPC
Identifying the sources of the vibroacoustic emissions that we both hear and feel is essential to creating comfortable vehicles.