3. Results and discussion3.1. Flow features3.1.1. Flow around the trainTo better exhibit the flow around train exposed to naturalwind, the surface pressure contour of the train is demonstrated in Figure 7. The aerodynamic performances oftrain on the windward side and the leeward side are obviously different. It is visible that a high-pressure regionis generated on the windward side of the train, whilea low-pressure region on all other sides. In addition, itcan be observed that a significant difference, the positivepressure reducing on the windward flank and the negative pressure increasing on the leeward flank, exists alongthe traveling direction from the front to rear, which maybe produced by the interaction of the moving train andincoming wind. Clearly the extreme pressure obtained atstagnation point, appears on the nose of head-car due tothe compressible effect of moving train on the air, whilethe lower pressure is given on the top and bottom oftail-car, perhaps indicating some separated flow in thisregion. It is worth remarking that the shielding effect ofweb member of truss bridge is depicted on the pressuredistribution of windward side.