Aerodynamic drag on the bullet trains
Abstract
The running resistance of electric trains can be divided into two resistances, one is the air resistance and the other is the mechanical resistance. The reduction of air resistance of high speed electric trains is especially important, as air resistance of trains increases faster than mechanical resistance in high speed. The air resistance of a long electric train like the 'Shinkansen' (Bullet Train) is evaluated as the combination of the pressure resistance which is exerted at the head and tail parts of the train and of the friction resistance which is exerted along side surfaces of the train and is proportional to the train length. The air resistance is measured from the difference of air resistance between long and short trains by the wind tunnel tests. The air friction resistance is measured from the pressure increase on the side surface of the train, when the train enters a tunnel. The combined resistance (air resistance and mechanical resistance) of the electric trains moving in the tunnel was measured and the resistance difference in and out of the tunnels were assumed to be the air resistance of the train. With this experiment, accuracies of measurement methods were analyzed.
- Publication:
-
Proceedings of the 5th and 6th Seminars on Investigation and Control of Boundary-Layer Transition
- Pub Date:
- October 1990
- Bibcode:
- 1990sicb.proc...15M
- Keywords:
-
- Aerodynamic Drag;
- Boundary Layer Transition;
- Computational Fluid Dynamics;
- Computerized Simulation;
- Rail Transportation;
- Rapid Transit Systems;
- Acceleration (Physics);
- Laminar Flow;
- Mechanical Impedance;
- Transfer Tunnels;
- Transonic Flow;
- Turbulent Flow;
- Fluid Mechanics and Heat Transfer