Tyre/road noise is a problem with high level of complexity. In the first part of this thesis, the measurements of noise generated by two commercial tyres in rotation are analysed. In the second part, it is proposed and developed an equivalent source model aimed at reconstructing and simulating the acoustic field generated by the rotation of tyre. An important part of the thesis is dedicated to the analysis of the deterministic and random contributions of the noise. The two contributions are separated by means of a proper processing of the measured signals in indoor experiments. The indoor experiment data are utilized for the identification and validation of the equivalent source model which is developed for the simulation of the acoustic field generated by a tyre in rotation. The results of the reconstruction and simulation of the acoustic field are more than satisfactory. It is verified that the proposed model can reconstruct and simulate either the deterministic contribution or the random one of the acoustic field in indoor experiment environment. The outdoor simulations are performed considering some of the principal differences between the indoor and outdoor experiment environments. The results of the outdoor simulations indicate that more differences between the indoor and outdoor experiment environments should be considered for obtaining the best results. This thesis is part of the research project Silent Tyre, under the cooperation agreement between Pirelli Tyre S.p.A. and Politecnico di Milano.
Il rumore di rotolamento dello pneumatico è un problema con alto livello di complessità. Nella prima parte del presente lavoro di tesi, sono analizzate le misure del rumore di rotolamento di due pneumatici commerciali. Nella seconda parte, viene proposto e sviluppato un modello a sorgenti equivalenti per la ricostruzione e simulazione del campo acustico generato dal rotolamento dello pneumatico. Una parte importante della tesi è dedicata all’analisi dei contributi deterministico e aleatorio al rumore, che vengono separati mediante una opportuna procedura di elaborazione dei segnali misurati nelle prove indoor. I dati indoor vengono utilizzati per identificare e validare il modello a sorgenti equivalenti per la simulazione del campo acustico generato da uno pneumatico in rotolamento. La ricostruzione e simulazione del campo acustico ha portato a risultati più che soddisfacenti. È verificato che il modello proposto può ricostruire e simulare sia il contributo deterministico che quello aleatorio del campo acustico nell’ambiente indoor. Le simulazioni outdoor sono eseguite considerando alcune tra le principali differenze tra ambiente indoor e outdoor. I risultati delle simulazioni outdoor indicano che altre differenze tra ambiente indoor e outdoor dovrebbero essere considerate per ottenere risultati migliori. Questa tesi è stata sviluppata all'interno del progetto di ricerca Silent Tyre, nell'ambito dell'accordo di cooperazione esistente tra Pirelli Tyre S.p.A. e Politecnico di Milano.
Tyre noise numerical modelling based on equivalent acoustic sources
LI, QIANQIAN
2016/2017
Abstract
Tyre/road noise is a problem with high level of complexity. In the first part of this thesis, the measurements of noise generated by two commercial tyres in rotation are analysed. In the second part, it is proposed and developed an equivalent source model aimed at reconstructing and simulating the acoustic field generated by the rotation of tyre. An important part of the thesis is dedicated to the analysis of the deterministic and random contributions of the noise. The two contributions are separated by means of a proper processing of the measured signals in indoor experiments. The indoor experiment data are utilized for the identification and validation of the equivalent source model which is developed for the simulation of the acoustic field generated by a tyre in rotation. The results of the reconstruction and simulation of the acoustic field are more than satisfactory. It is verified that the proposed model can reconstruct and simulate either the deterministic contribution or the random one of the acoustic field in indoor experiment environment. The outdoor simulations are performed considering some of the principal differences between the indoor and outdoor experiment environments. The results of the outdoor simulations indicate that more differences between the indoor and outdoor experiment environments should be considered for obtaining the best results. This thesis is part of the research project Silent Tyre, under the cooperation agreement between Pirelli Tyre S.p.A. and Politecnico di Milano.| File | Dimensione | Formato | |
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2017_07_Li.pdf
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https://hdl.handle.net/10589/135463