Efficient CFD Simulation Process for Aeroacoustic Driven Design 2010-36-0545
The transport industries face a continuing demand from customers
and regulators to improve the acoustic performance of their
products: reduce noise heard by passengers and passersby; avoid
exciting structural modes. In both the aerospace and automotive
areas, flow-induced noise makes a significant contribution, leading
to the desire to understand and optimize it through the use of
simulation.
Historically, the need for time-consuming, computationally
expensive transient simulations has limited the application of CFD
in the field of acoustics. In this paper are described efficient
simulation processes that, in some instances, remove the
requirement for transient analyses, or significantly reduce the
total process time through intelligent pre-processing.
We will outline this process and provide both automotive and
aerospace industrial examples, including analyses of highly complex
geometries found in real life. Section 2 describes a modeling
hierarchy which includes steady-state, transient and
frequency-based time-periodic methodologies. Section 3 contains
four popular classes of application spread across the
transportation sectors: - Airframe noise simulation of a complex
nose landing gear; - Aeroacoustics of avionic cooling rack in an
Airbus cockpit; - Automotive sunroof buffeting with structural
impedance; - Fan noise signature in the presence of gusts.
For these case studies, the main focus is the prediction of
aeroacoustic noise sources. The propagation of noise to the
far-field is not considered here, though some qualifying comments
are made in section 2.4.
