<div class="section abstract"><div class="htmlview paragraph">Many sources and paths cause interior cabin noise. Some noise from an electric
vehicle is unique and different from a vehicle with an internal combustion
engine. Especially, whine noise occurs due to the particular orders of the
electromagnetic force of an electric motor and transmission gears, which is
tonal and usually reaches high frequencies. This paper covers structure-borne
(SB) and airborne (AB) aspects to estimate whine, and the difference between the
two characteristics is distinguished. The focus lies mainly on the process of
virtual vehicle development and application for performance improvement. First,
to predict SB whine, an e-powertrain is modeled as a finite element model (FEM),
and electromagnetic (EM) forces are calculated. A vehicle model is also modeled
as an FEM, in which interior sound packages are carefully modeled as they play
an important role in the medium-frequency region. The e-powertrain and vehicle
models (being simulated separately) are combined to obtain cabin noise up to 1.5
kHz. Design studies show that the stiffness of mount insulators and the panel
stiffness of the vehicle can be substantial design variables to reduce the SB
whine. Second, the study highlights a simulation method to predict interior
airborne whine up to 8 kHz by combining the FEMs of the e-powertrain and the
vehicle’s exterior cavity with a statistical energy analysis (SEA) model of a
vehicle. Path contribution can be identified by defining source strength and
acoustic transfer function of airborne paths. Design modifications, including
encapsulation of the e-powertrain, show this simulation process could be
practically useful to reduce the airborne whine at high frequencies.</div></div>