전체 공기저항 저감을 위한 전후대칭열차 전두부 형상 최적설계

Nose shape optimization of the high speed train have to aim the reduction of the total aerodynamic drag considering the driving in the both way. Therefore, 3-D shape modeling is necessary for the accurate simulation of the wake area behind the train. Nose shape optimization is performed with the Vehicle Modeling Function which is 3-D modeling available. The 3-car long streamlined train shape is constructed and viscous compressible flow solver is adopted with unstructured meshes to predict the aerodynamic drag. The total aerodynamic drag of the train with the optimized shape was reduced by 5.8% when compared to the base model. The low-risen and long vertical nose shape of the optimized shape weakens the whirled flow around the nose tip behind the train rear nose and reduces the total aerodynamic drag. The flow change around the rear nose is dominant than that around the front nose.