Abstract
The Energy Boundary Element Method (EBEM) was originally developed for computing
acoustic radiation at high frequencies from a set of incoherent acoustic intensity boundary
conditions prescribed on the surface of the radiator. The acoustic energy density and intensity
constitute the primary variables for the EBEM. The corresponding integral formulation is
developed similarly to the conventional boundary element method. Another area where the
EBEM has also been applied is in computing the acoustic field around an automobile that
originates from typical airborne noise sources (e.g. tire patches, engine, exhaust, etc.) in the
frequency range between 400 Hz - 10,000 Hz. The acoustic field computed by the EBEM
can provide the acoustic loading information for an energy based (Energy Finite Element
Method (EFEM) or Statistical Energy Analysis (SEA)) interior airborne noise analysis. This
new computational capability can eliminate expensive and time consuming tests conducted
for characterizing the acoustic field around a vehicle for airborne noise considerations.
Theoretical aspects of the EBEM are discussed in this paper. Comprehensive vehicle
analyses where test data are compared to simulation results for the acoustic field generated
from an acoustic source placed at several different locations are presented. It is demonstrated
that the EBEM can capture correctly the acoustic field around a vehicle and perform
challenging analyses reliably with small computational resources. A case study is presented
for demonstrating how EBEM and EFEM can be combined for a complete airborne noise
simulation.
Keywords - airborne noise; boundary element analysis; energy finite element method; statistical energy analysis