Wave Equation Model

Wave Equation Acoustic Model — ANSYS Fluent CFD Simulation

Description

This project explores the Wave Equation acoustic model in ANSYS Fluent, one of the most versatile acoustic-modeling techniques available in modern CFD. The Wave Equation model describes how sound propagates through a medium, and this project applies it to a fundamental problem in hydroacoustics: the noise induced by water flowing around a cylinder. Because the medium here is water rather than air, the case also introduces the specific challenges of liquid-based (hydroacoustic) simulation, where sound behaves differently than it does in a gas. As the opening project of the Acoustics: Beginner CFD Training Package, it introduces the most fundamental acoustic model — sound propagation itself — establishing the foundation for the FW-H and Broadband models 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 in the liquid, using a pressure-based solver for the incompressible flow, with the Wave Equation acoustic model activated for high-fidelity results. The setup supports extracting sound-pressure levels across a broad frequency range — up to 100,000 Hz — and exporting the acoustic source data in ASD format for further analysis.

Analysis

Post-processing focuses on the sound-pressure levels in the liquid environment, interpreted in the frequency domain to understand how sound energy is distributed across a wide spectrum. The results reveal the high-frequency acoustic behavior up to 100,000 Hz, help identify the critical frequency ranges for engineering applications, and allow the acoustic behavior in water to be compared with that in air — highlighting the unique challenges of hydroacoustic simulation. This kind of analysis is central to naval engineering and underwater acoustics, hydraulic system design, oceanographic research, and industrial noise reduction. By the end of this project, you'll be able to set up a transient acoustic simulation with the Wave Equation model, configure it for a liquid medium, extract and interpret sound-pressure levels across a broad frequency range, and apply the results to noise analysis in liquid-based engineering.