Numerical Analysis for Roof Rack Crossbar Wind Noise Prediction and Minimization

Wind noise from crossbars in a vehicle roof rack system is investigated using the computational fluid dynamics (CFD) model. Favre-averaged Navier–Stoke’s equation is used to resolve the time-dependent effects of the flow turbulence. The pressure data of a point in the flow domain is processed to obtain the wind noise in terms of sound pressure level (SPL). An aerodynamic problem involving a right circular cylinder is used to validate the CFD model against experimental data. Later, the numerical analysis is performed on a crossbar of length 1 m for a wind speed of 40 m/s, to obtain the broadband and narrowband noise. Further, three configurations of the crossbar are investigated to analyse their effect on the strength of Aeolian tone. Ultimately, a crossbar configuration is obtained that shows a 50% reduction in noise.