Abstract
The narrow gauge railway vehicle is proceeding with making the drive-system noise which has the possibility to generate noise a low noise. However, so far, as for the measure which decreases the aerodynamics noise of the induction traction motor noise which is one of the sources of the drive-system noise, the way of finding an optimum by the trial and error using the actual device was caught. Therefore, the mechanism of the generation of the aerodynamics noise hadn't been complete as the fluid acoustic analysis but the environment was ready as the tool which analyzes a fluid sound. According to this, we can choose the optimum by fluid acoustic analysis before the production of the actual machine.
