Train-induced pressures and flows in large underground stations

Airflows caused by trains travelling at high speed through large underground stations arc investigated with particular attention to velocities likely to be experienced by passengers waiting on platforms. For the particular cases considered, bulk airflows due to train displacement effects are found to be unlikely to cause violations of usual comfort criteria. However, the criteria would be violated for people standing too close to the moving trains. In the case of bulk airflows, comparisons are made between alternative predictions obtained using 1D and 3D methods. It is found that 1D methods can give sufficient accuracy for many design purposes. It is also found that large-scale circulations in station boxes arc quite sensitive to the relative resistance to flows though alternative routes to/from the station box.