Method to reduce a vehicle pass-by noise
A simulation method of a vehicle Pass-By Noise (PBN), which method comprises the following steps: (i) providing a tyre model, a vehicle model and one or more sound absorbent material models as inputs to a calculation module; (ii) simulating, by means of the calculation model, a Pass-By noise (PBN) generation profile of one or more rolling tyres based upon the tyre model; (iii) identifying, by means of the calculation module, one or more noise paths at the vehicle body; and (iv) selecting a position and an absorbent material property of an absorbent material to be positioned at vehicle body in order to minimize Pass-By Noise.
1 . A computer-implemented simulation method of a vehicle Pass-By Noise (PBN), the method comprising:
(i) providing, as inputs to a calculation module:
a tire acoustic model including modelled pattern features comprising one or more of lateral slots, sipes, and chamfers;
a vehicle body part model; and
one or more sound absorbent material models;
(ii) identifying, using the calculation module, one or more noise paths at the vehicle body part for each frequency of a predetermined frequency range; and
(iii) selecting a position and a material property of a sound absorbent material to be positioned at the vehicle body part in order to minimize Pass-By Noise,
wherein step (iii) comprises minimizing Pass-By Noise at one or more frequencies in a range of about 500-2000 Hz, and
wherein in step (iii) the selected position of the sound absorbent material is one or more specific locations within a vehicle wheel-arch and/or a vehicle underbody.
2 . The method of claim 1 , wherein the one or more sound absorbent material models include a model of a foam material, of polyurethane (PU), or of an Ethylene-Propylene Diene Monomer (EPDM).
3 . The method of claim 2 , wherein step (iii) comprises selecting a combination of different sound absorbing materials.
4 . The computer-implemented simulation method of claim 1 , provided as part of a vehicle designing method.
5 . A vehicle manufacturing method, comprising:
(i) providing, as inputs to a calculation module:
a tire acoustic model including modelled pattern features comprising one or more of lateral slots, sipes, and chamfers;
a vehicle body part model; and
one or more sound absorbent material models as inputs to a calculation module;
(ii) identifying, using the calculation module to perform an acoustic simulation based on the tire acoustic model and the vehicle body part model, with vibration data of the tire acoustic model as boundary conditions, one or more noise paths at the vehicle body part for each frequency in a range of about 500-2000 Hz;
(iii) selecting one or more positions within a vehicle wheel-arch and/or underbody and a material property of a sound absorbent material to be positioned in the selected one or more positions in order to minimize Pass-By Noise; and
(iv) applying sound absorbing material having the selected material property in the selected one or more positions, such that a material weight is minimized, without affecting vehicle performances in terms of Rolling Resistance coefficient (RRc), behaviour in wet conditions, and vehicle handling.
6 . The vehicle manufacturing method of claim 5 , wherein the one or more sound absorbent material models include a model of a foam material, of polyurethane (PU), or of an Ethylene-Propylene Diene Monomer (EPDM).
7 . The vehicle manufacturing method of claim 6 , wherein the step (iii) comprises selecting a combination of different sound absorbing materials.