Theoretical Models And The Experimental Study Of The Horn Effect

Tire/road noise becomes the major component of the modern transportation noise as the total noise produced by power transmission system has been greatly reduced. Tire noise will be seriously amplified by the geometrical structure formed by the curved surface of the tire and ground plane, which leads to a greater effect on the transportation and the living environment of residents. To analyze and predict this effect, this dissertation pays attention to the investigation of prediction models and experiments. Three models, the spherical model based on the expansion with the spherical wave, the 2D and 3D cylindrical model based on the expansion of the cylindrical wave and the multipole model, which can realize predictions of high precision have been set up and examined through experiments. In addition, the experiments of two cylinders having the same sizes with a real tire, a cylinder having measurement holes on the surface and a dissected cylinder have been carried out to analyze the horn effect when the locations of the source and receivers are different and to analyze the horn effect at a loaded condition. The precision of each theoretical model are examined based on the data of experiments. What's more, this dissertation makes a conclusion about the rules of how the locations of the source and receivers influence the horn effect. The results of this dissertation could be beneficial to the control as well as the investigation of the mechanisms of tire/road noise.