Unraveling the Secrets of Noise Generated by Flow past a 2-D Cylinder

Table of Contents

1. Introduction
2. Modeling Flow Induced Noise
   1. Folks-Williams Hawking's Formulation
   2. Tutorial Overview
3. Setting Up The Simulation
   1. Problem Description
   2. Mesh Quality
   3. Activating the Elias Model
   4. Viscous Models
4. Boundary Conditions and Material Properties
   1. Cell Zone Conditions
   2. Inlet Boundary Condition
   3. Reference Values
   4. Solution Methods
5. Running the Simulation
   1. Initialization
   2. Calculating Drag and Lift Coefficients
   3. Post-Processing with CFD Post
6. Extracting Acoustic Noise
   1. Acoustics Models
   2. Defining Sources
   3. Defining Receivers
   4. Exporting Acoustic Noise
7. Post-Processing Acoustic Signals
   1. Analyzing Pressure Fluctuations
   2. Lag and Attenuation of Signal
   3. Fast Fourier Transformation
8. Conclusion

Modeling Flow Induced Noise using Folks-Williams Hawking's Formulation

Modeling flow-induced noise is a complex process that requires accurate simulation techniques. In this tutorial, we will demonstrate how to model a 2D turbulent flow across a circular cylinder using Large Eddy Simulation (LES) and compute flow-induced noise using the SIS fluence acoustics model.

Introduction

Flow-induced noise is a crucial aspect to consider in various engineering applications. Understanding the noise generated by flowing fluids is essential in designing efficient and low-noise systems. By accurately modeling and simulating the flow-induced noise, engineers can optimize designs and minimize unwanted noise.

Modeling Flow Induced Noise

Flow-induced noise can be accurately modeled using Folks-Williams Hawking's formulation. This formulation considers the acoustic analogies of the fluid flow and allows for the calculation of sound pressure levels at different locations. By understanding the principles behind this formulation, engineers can effectively predict and analyze the noise generated by fluid flow.

Tutorial Overview

In this tutorial, we will walk You through the step-by-step process of modeling flow-induced noise using the Folks-Williams Hawking's formulation. We will start by setting up the simulation, including defining the problem description, ensuring mesh quality, and activating the Elias model. Then, we will discuss the boundary conditions and material properties required for accurate simulation. Next, we will run the simulation and calculate drag and lift coefficients. We will also post-process the results using CFD Post to Visualize pressure fluctuations in the domain. Finally, we will extract acoustic noise and analyze the received signals to gain insights into the flow-induced noise.

Conclusion

Modeling flow-induced noise using Folks-Williams Hawking's formulation is a powerful tool for engineers to understand and predict the noise generated by fluid flow. By accurately simulating and post-processing the results, engineers can optimize designs and minimize noise levels in various engineering applications.

FAQ

Q: What is flow-induced noise? A: Flow-induced noise refers to the noise generated by the turbulence and interactions of fluid flow with various structures or boundaries. It is commonly observed in applications involving fluid flow, such as aerodynamics, hydrodynamics, and HVAC systems.

Q: How can modeling flow-induced noise be beneficial? A: Modeling flow-induced noise allows engineers to understand and predict the noise levels associated with certain fluid flow conditions. This information is crucial in designing efficient systems, reducing noise pollution, and improving overall performance.

Q: What are the key components of the Folks-Williams Hawking's formulation? A: The Folks-Williams Hawking's formulation considers the acoustic analogies of fluid flow, taking into account the pressure fluctuations and sound generation mechanisms. It enables the calculation of sound pressure levels at specific locations based on the flow conditions and geometry.

Q: How is flow-induced noise extracted and analyzed in the simulation? A: In the simulation, acoustic noise can be extracted by defining sources and receivers in the domain. The pressure fluctuations at the receiver locations are then analyzed using post-processing techniques such as fast Fourier transformation to understand the frequency content and intensity of the noise.