Modelling and evaluating interior tire-road noise

Exterior and interior tire-road noise is a common problem for car and tire manufactures. Exterior tire-road noise is bounded by SPL limits mentioned on a vehicle pass-by as described in UN-ECE R117 and EC R661/2009. Interior tire-road noise on the other hand is determined by market requirements. Predicting interior tire-road noise and determining these market requirements are still very challenging. First a brief review of interior and exterior tire-road noise model approaches is given in order to distinguish which model approach for interior tire-road noise is most promising. Some experimental considerations are given as a guide line for this evaluation. A full FEM/BEM exterior tire-road noise model combined with measured structure and air-borne transfer paths appears to be most promising. By playing this simulated noise over head phone for a relative small jury one obtains an engineering tool where the tire-road parameters, for a specific car, can be optimised for to a comfortable interior sound field