Broadband Noise Sources Model

Broadband Noise Sources Acoustic Model — ANSYS Fluent CFD Simulation

Description

This project explores the Broadband Noise Sources acoustic model in ANSYS Fluent, a valuable technique for identifying where noise is generated in a flow. Unlike the transient FW-H and Wave Equation methods, the Broadband Noise Sources model gives a quick, steady picture of the acoustic source distribution — a low-cost way to locate the regions responsible for noise before committing to a full transient simulation. 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 completes the trio of core acoustic models, adding the source-identification method to the propagation-based Wave Equation and FW-H models taught before it.

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. The analysis uses a pressure-based solver for the incompressible flow, with the Broadband Noise Sources model implemented for a comprehensive picture of the acoustic sources. The setup supports extracting acoustic power-level contours and analyzing the LEE-Self noise and LEE Shear-noise source distributions, as well as comparing the noise generation with and without the cylinder obstruction.

Analysis

Post-processing focuses on the acoustic power-level contours, interpreted to understand the relationship between acoustic pressure and decibel levels and to locate the critical areas of noise generation around the cylinder. The model distinguishes between the LEE-Self noise and LEE Shear-noise sources, clarifying the mechanisms responsible for the noise, and comparing the cases with and without the cylinder reveals the impact of a flow obstruction on noise generation. This kind of analysis is essential across aerospace, automotive design, wind-turbine development, and HVAC optimization. By the end of this project, you'll be able to set up a Broadband Noise Sources simulation, extract and interpret acoustic power-level contours, distinguish between noise-source types, and identify where noise originates in a flow — a fast, practical basis for noise-reduction design.