Sound Generation on a Car with and without Spoiler

Description

Sound Generation (Acoustic) on Audi Car with and without Spoiler, CFD Simulation Ansys Fluent Training

Sound Generation on Audi Car with and without Spoiler has been simulated in this project, and the simulation results have been investigated using ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

Acoustics is a science that deals with the study of mechanical waves in gases, liquids, and solids, including vibration, sound, ultrasound, and infrasound. It concerns production, control, transmission, reception, and sound effects.

The present model is designed in three dimensions using the Design Modeler software. This geometry has meshed in ICEM software.

Sound Generation Methodology

The problem simulates sound pressure waves around a car using Ansys Fluent software. Aeroacoustics is a branch of acoustic science that investigates the production of Noise.

In general, Noise can be generated by the movement of turbulent fluid or from collisions of aerodynamic forces with surfaces. Turbulent fluid motion is associated with pressure and density gradient, resulting in velocity gradient, and these changes have oscillating nature and are the source of sound waves.

Topics related to sound waves are essential in aerospace applications and fields Because the sound waves produced in aerospace devices such as airfoils are very high.

This project examines the sound waves generated around the body of a car. This project uses an acoustic model in Fluent software to simulate and analyze sound or acoustic waves. The Broadband Noise Sources model has also been used to define the acoustic model of the present work.

Definitive density is equivalent to air density, i.e., 1.225 kg / m3, sound speed is equivalent to sound speed in the air, i.e., 340 m / s, and the reference acoustic power is equal to 1e-12 pascal. In this model, an Audi car with and without a spoiler is designed, and the airflow moves towards this car with speed equal to 70 m/s.

This project has been carried out in two modes, with and without spoilers. Moreover, the SST k-omega model is used to solve turbulent fluid equations.

Sound Generation Conclusion

At the end of the solution process, two-dimensional contours related to pressure and velocity, as well as diagrams of changes in velocity and acoustic power level in both two states, are obtained.

The figures show the amount of change in acoustic power level (dB) or the amount of sound pressure in terms of location in the longitudinal direction. This location indicates a few meters before the location of the car body, then on the surface of the car body, and finally a few meters after the car body.

As can be seen in the plots, the sound wave generated due to the hit of the airflow to the car is reduced in the case of a car with a spoiler. The Acoustic power level in the case without a spoiler is about 95 dB and in the case with a spoiler is about 70 dB.

Although in the far-field part of the geometry behind the car, in the case of a car with a spoiler is more than the other case.

A car without Spoiler: