Estimation of Aerodynamic Bogie Noise Through Field and Wind Tunnel Tests

A method has been developed to determine the aerodynamic noise from the bogie of a high-speed train using a two-dimensional microphone array in a wind tunnel. First, the flow velocity under the train car in the rail direction was measured in a field test. Second, the flow distribution was simulated in the wind tunnel. Third, aerodynamic noise generated by a bogie was estimated from the source distribution measured using a two-dimensional microphone array. Finally, the noise generated from the lower part of the car, which was obtained by adding the aerodynamic noise and the rolling noise estimated by the TWINS model, was compared with the result obtained from the field test. It was found that the estimated noise shows good agreement with the measurement obtained in the field test. The estimated lower part noise levels were consistent with the actual experimental measurements. This conclusion suggests that this method is appropriate to estimate aerodynamic bogie noise quantitatively. It is also shown that below 500 Hz the contribution of the aerodynamic bogie noise is more than those of the rolling and machinery noise.