Experimental and Numerical Investigation of the Metal Sheet for Automotive

Shehab Ashraf Salem

Master's thesis

Experimental and numerical investigation of the metal sheets for automotive

Abstract:

This report investigates the aero-acoustic noise generated by sheet metals of three different structures. The investigation is done both experimentally and numerically in order to find the sheet of best acoustic performance. Each sheet was tested experimentally in a wind tunnel in the velocity range of 9 to 20 m/s where the produced sound was recorded by a microphone. The experiment aimed at finding which sheet produces louder noise. Moreover, the velocity fluctuation after the sheets trailing edge was captured by a Hot Wire Anemometer to find the dominant frequency of vortices and calculate turbulence intensity. Finally, the case of highest velocity was numerically simulated using Ansys fluent where the simulation was validated by the experimental results. The numerical analysis used LES turbulence model with Kinetic Energy Transport sub-grid model. Ffowcs-Williams & Hawkings model was used to predict the acoustic sources. Agreements were found between the trend of acoustic noise produced from experiment and numerical simulation over some ranges of frequency.

Abstract:

This report investigates the aero-acoustic noise generated by sheet metals of three different structures. The investigation is done both experimentally and numerically in order to find the sheet of best acoustic performance. Each sheet was tested experimentally in a wind tunnel in the velocity range of 9 to 20 m/s where the produced sound was recorded by a microphone. The experiment aimed at finding which sheet produces louder noise. Moreover, the velocity fluctuation after the sheets trailing edge was captured by a Hot Wire Anemometer to find the dominant frequency of vortices and calculate turbulence intensity. Finally, the case of highest velocity was numerically simulated using Ansys fluent where the simulation was validated by the experimental results. The numerical analysis used LES turbulence model with Kinetic Energy Transport sub-grid model. Ffowcs-Williams & Hawkings model was used to predict the acoustic sources. Agreements were found between the trend of acoustic noise produced from experiment and numerical simulation over some ranges of frequency.

Keywords

CFD, Ansys Fluent, Aero-Acoustic, Ffowcs-Williams & Hawkings

Language used: English

Date on which the thesis was submitted / produced: 21. 5. 2018

Thesis defence

• Supervisor: prof. Ing. Karel Fraňa, Ph.D.

Technical University of Liberec

Faculty of Mechanical Engineering

Master programme / field:
Mechanical Engineering / Machines and Equipment Design