SEA Wind Noise Load Case for Ranking Vehicle Form Changes

Vehicle manufacturers demand early design assessment of vehicle wind noise attribute so as to eliminate engineering waste induced by late design changes. Vehicle wind noise attribute can be simulated with a Statistical Energy Analysis (SEA) model using exterior surface turbulence pressure on the vehicle greenhouse panel as the wind noise load. One important application of SEA wind noise model is the wind noise assessment for vehicle form design. Vehicle form optimization for wind noise plays an important role in lightweight vehicle architecture, since that reduction in the wind noise load will compensate the loss of vehicle body acoustic attenuation caused by down-gauge glazing and body panels. In this paper, two SEA wind noise load cases currently used in vehicle SEA wind noise modeling have been analyzed and evaluated against vehicle measurements. Two types of evaluations have been made: prediction of the interior cabin noise level at driver's ear location and simulation of level change in the interior cabin noise corresponding to different exterior mirrors. The correlation result shows that current wind noise load cases over-predict the interior cabin noise and mis-simulate the level change in interior cabin noise in response to mirror shape change. A new SEA wind load case has been proposed. The prediction of the interior cabin noise from the proposed load case shows a good correlation with vehicle measurement. The correlation result shows that the proposed load case improves the simulation of change in the interior cabin noise in response to mirror shape change. Further effort is needed to improve the determination and representation of acoustic energy in the pseudo acoustic near field.