The Effect of Scaling of Owl's Flight Feather on Aerodynamic Noise at Inter-coach Space of High Speed Trains based on Biomimetic Analogy

생체모방공학을 이용한 고속철도 차간 공간에 적용한 부엉이 깃 형상 크기에 따른 공력소음 저감 연구

An analysis and design method for reducing aerodynamic noise in high-speed trains based on biomimetics of noiseless flight of owl is proposed. Wind tunnel testing and numerical CFD (Computational Fluid Dynamics) simulation for the basic inter-coach spacing model are carried out, and their results compared. To determine the effect of scaling of the owl's flight feather on the noise reduction, two-fold and a four-fold scaled up model of the feather are constructed, and the numerical simulations are carried out to obtain the aerodynamic noise levels for each scale. Original model is found to reduce the noise level by 10 dB, while two-fold increase in length dimensions reduces the noise by 12 dB. Validation of numerical solution using wind tunnel experimental measurements are presented as well.