IMPROVEMENT OF LIFT-TO-DRAG RATIO OF THE AERO-TRAIN

Abstract

Aero-Train is a new concept of environment friendly high speed transport system invented by our group. In order to realize this concept, improvement of the aerodynamic performance is essential. Our goal is to attain the overall lift to drag ration up to 25. Presently it is around 13 to 15. Some of the possible reasons why the value is low are in the interference drag and induced drag around lifting and guide wing junction. Flow separates largely at suction surfaces of the wing section enhanced by the existence of horizontal and vertical walls. Separation control study is conducted in present investigation using CFD and EFD approaches. Drastic improvement of lift to drag ratio was achieved by introducing several devices at the wing section. . Over 20% of Carbon Dioxide emission is from the general transport system. Fluid dynamic drag force is proportional to the square of the speed of the vehicle. Therefore in the case of high speed transport system including aircrafts, reduction of the aerodynamic drag force is essential from the point of environmental pollution problem. The Laminar-Turbulent Transition Symposium is essentially important in improvement of overall performance of aircrafts, namely increasing lift to drag ratio by maintaining laminar boundary layer over the vehicle surface. . In the case of high speed ground transport systems like Shinkansen in Japan or Trans Rapid in Germany where cruising speeds exceed 300 km/h, around 90-% of the total drag is from aerodynamic drag. From such a point of view, we need to consider them as aircrafts. Therefore, increasing the lift to drag ratio of ground transport system is as important as that for aircrafts.