Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 01 Oct 2016

Computational Aeroacoustic Analysis of a Rolling Tire

Page Range: 262 – 279
DOI: 10.2346/tire.16.440403
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ABSTRACT

Road traffic is one of the major sources of noise in modern society. Consequently, the development of new vehicles is subject to increasingly stringent guidelines in terms of noise emissions. The main noise sources of common road vehicles are the engine, the transmission, the aerodynamics, and the tire-road interaction. The latter becomes dominant between 50 and 100 km/h, speeds typical of urban and extra-urban roads. The noise that arises from the tire-road interaction is the combination of structural vibration and aeroacoustics phenomena that create and amplify or reduce the sound emitted from the tire. The aim of the numerical analysis presented in this study is to investigate the aeroacoustic noise-generation mechanisms of the tire and at the same time provide a tool to develop a low-noise tire. The work is divided into two parts: analysis of the steady aerodynamics and the unsteady aeroacoustic analysis. In the first part, the numerical solution of the Navier-Stokes equation allows us to screen aerodynamic phenomena, such as separations or jet streams that can produce noise. In the second part, these aspects are analyzed in greater detail by means of aeroacoustic analogies, confirming the capability of the numerical tool to provide suggestions for the development of quieter tires.

Keywords: tire; pattern; noise; aeroacoustic; simulation; CFD; LES
FIG. 1
FIG. 1

Sound pressure level (SPL) in A-weighted third-octave bands for a slick tire (smooth) and one with longitudinal grooves (straight groove).

FIG. 2
FIG. 2

The tire model of a 205/55 R16 in scale 1:2.

FIG. 3
FIG. 3

Above, the velocity magnitude contour map on a plane at 2 mm from the road surface. Below, the vector velocity field on a cut section at the inlet of the pipe generated from the longitudinal tire groove and the road surface.

FIG. 4
FIG. 4

Contour maps at the pipe inlet of static pressure and X-vorticity, left and right, respectively.

FIG. 5
FIG. 5

Left, static pressure and Z-vorticity contour maps of the pipe in a plane at 2 mm from the road (mid of the pipe height). Right, velocity component fluctuations in the center point of the pipe.

FIG. 6
FIG. 6

Contour maps of static pressure (on the left) and Z-vorticity (on the right) on two orthogonal sections of the pipe outlet. On the upper part, the cutting plane is normal to the tire axle; in the lower part, the plane is at 0.5 mm from the road surface.

FIG. 7
FIG. 7

Contour maps of static pressure and Z-vorticity (left and right, respectively) on a cutting plane at 1 mm from the road surface.

FIG. 8
FIG. 8

Standing wave mode inside the pipe open-open within the contact patch. The probe records the pressure signal at the center of the duct.

FIG. 9
FIG. 9

Pressure signal recorded by the probe placed at the center of the pipe featured by the tire groove and the road surface.

FIG. 10
FIG. 10

On the left, sound pressure level A-weighted of the pressure signal recorded inside the tire pipe; on the right, the A-filter transfer function.

FIG. 11
FIG. 11

Sound pressure level A-weighted of the pressure signal recorded inside the tire pipe filtered in third-octave bands.

FIG. 12
FIG. 12

On the left, A-weighted sound pressure levels of the pressure signals recorded in four probes placed around and inside the contact patch of the tire with the road surface. On the right, the position of the four probes with the reference of the footprint shape.

FIG. 13
FIG. 13

The position of the three receivers used in the FW-H model.

FIG. 14
FIG. 14

Pressure signal calculated at the receivers of Figure 13.

FIG. 15
FIG. 15

Sound pressure levels A-weighted of the pressure signal recorded in the far field.

FIG. 16
FIG. 16

Sound pressure levels A-weighted of the pressure signals filtered by third-octave bands.

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