Ffwocs Williams & Hawkings (FW-H) Model

Ffowcs Williams & Hawkings (FW-H) Acoustic Model — ANSYS Fluent CFD Simulation

Description

This project explores the Ffowcs Williams & Hawkings (FW-H) acoustic model in ANSYS Fluent, one of the most powerful acoustic-simulation techniques available in modern CFD. The FW-H model is the standard method for predicting the far-field noise radiated by a flow — it takes the unsteady flow near a body and propagates the resulting sound out to distant receivers. This project applies it to a fundamental problem in aeroacoustics: the noise induced by airflow around a cylinder. Within the Acoustics: Beginner CFD Training Package, this project introduces the workhorse aeroacoustic method, building on the Wave Equation model toward the standard tool for far-field noise prediction used throughout the applied cases that follow.

Methodology

The optimized 2D geometry is created in ANSYS Design Modeler and meshed in ANSYS Meshing with a structured grid of 23,264 elements suited to acoustic simulation. A transient analysis is set up to capture the time-dependent acoustic behavior, using a pressure-based solver for the incompressible flow, with the Ffowcs Williams & Hawkings acoustic model implemented to predict the radiated sound. The setup supports extracting sound-pressure levels, analyzing A-weighted acoustic pressure, and performing Fourier transforms for frequency-domain analysis.

Analysis

Post-processing focuses on the sound-pressure levels, interpreted in the frequency domain to understand how sound energy is distributed across frequencies. The A-weighted acoustic pressure is evaluated to tailor the data to human hearing perception and identify the critical frequency ranges for human-centric acoustic design, while the spatial distribution of acoustic pressure at varying distances from the source illustrates the principles of acoustic attenuation. This kind of analysis is essential across aerospace (aircraft noise reduction), automotive design (vehicle aeroacoustics), wind-turbine development, and environmental noise assessment. By the end of this project, you'll be able to set up a transient FW-H acoustic simulation, extract and interpret sound-pressure levels and A-weighted data, perform frequency-domain analysis, and evaluate how noise attenuates with distance from the source.