A STUDY ON THE AERODYNAMIC DRAG OF THE VEHICLES RUNNING IN THE TUNNEL USING COMPUTATIONAL FLUID DYNAMICS

In order to analyze effects of various parameters on aerodynamic drag of an underground freight system and to suggest a plan for reducing aerodynamic drag, a three-dimensional simulation using computational fluid dynamics has been made and aerodynamic drags respectively for a single vehicle running and a platooning in which a group of two or more aligned vehicles run have been calculated. A concept design of an underground freight system has been made to obtain two concept designs, i.e., a pallet-exclusive transportation design and a vehicle-compatible transportation design. ANSYS FluentTM has been used for modeling, meshing and numerical analysis for respective designs. It can be known from the analysis that aerodynamic drag significantly increases in an underground tube compared to an open space and the amount of an increase of aerodynamic drag is considerably affected by the sectional area ratio between the tube and the capsule. In addition, the aerodynamic drag in the platooning is reduced by up to 10% compared to the single running depending on the number of the capsules and the distance between the capsules.