February 7, 2022
Hear that? A plane flying over a neighborhood. The fan on your laptop. Acres of spinning wind turbines. All around us, machines are making noise. How much noise is too much? How far does the sound travel? Where, exactly, is all this noise coming from?
Aeroacoustics simulation, the study of sound generated from a flowing fluid, is how engineers and designers identify the origin of a noise, understand its range of impact, and model solutions to reduce or eliminate the noise to comply with sound regulations and improve user experience.
Across industries, aeroacoustics simulation helps engineers analyze the generation of sound to improve comfort and safety. For example, in manufacturing, simulation can help identify hearing-loss hazards caused by the close proximity of equipment to operators. In marine turbines, it can help protect sea life by identifying ways to reduce underwater noise pollution.
In this article, we’ll look specifically at automotive, where thousands of parts are being constantly impacted by flowing air. Here, aeroacoustics simulations can quickly identify the source of a sound and explore ways to silence it.
As a passenger rides in a car, they can perceive a variety of sounds that contribute to overall noise — all of which provide their own challenges for modeling.
Aeroacoustics simulation helps predict the combined impact of noise sources on the overall sound level in specified locations — for instance, the driver’s seat. Being able to predict noise enables designers to make modifications on car details (e.g., side mirror shape, some door gaps, vents, etc.) and materials to comply with regulations and improve the comfort of the passengers.
Ansys Fluent can solve complex aeroacoustics problems and provide an extensive set of modeling options and post-processing capabilities to improve acoustic design using a variety of methods:
In the latest Ansys software release, 2022 R1, we have introduced a new acoustics workflow that couples Ansys Fluent CFD simulations to Ansys Sound. This enables engineers to use advanced acoustics analysis techniques to analyze the acoustic pressure signals computed by CFD, including:
During the solution setup in Ansys Fluent, it’s possible to define an array of receivers and propagate the noise sources to them. The new Sound Analysis module extends Ansys Fluent acoustics capabilities, enabling engineers to hear what you compute in your CFD simulation.
Even short acoustics signatures generated at receiver locations during CFD simulations can be turned into high-quality audible long files. In addition, psychoacoustic analysis tools can provide insight into the impact of predicted sounds on human ear perception. The acoustics analysis in Ansys Fluent also support Frequency Response Function, which allows users to:
With a single click, it’s possible to transfer the acoustic signals and launch more sophisticated acoustics analyses in Ansys Sound.
To hear the composition of different noises on an Alfa Romeo Giulietta (courtesy FCA Italy), check out the Fluent acoustics interactive 3D model below.