Velocity distribution around the train in the tunnel at different heights for cases 1–3.

<p>(a) <i>Z</i> = 0.25 m, height of the train bogie; (b) <i>Z</i> = 1.85 m, half of the train height; and (c) <i>Z</i> = 3.8 m, above the top of the train.</p

The static pressure and velocity variations in two sides of tunnel for case 2.

<p>(a) the wave diagram; (b) time history of the static pressure and longitudinal velocity.</p

Computational domain and boundary conditions.

<p>Computational domain and boundary conditions.</p

Comparison of the longitudinal velocity along the train for case 2 and open air.

<p>Comparison of the longitudinal velocity along the train for case 2 and open air.</p

Longitudinal velocity distributions along the tunnels for cases 2 and 3.

<p>Longitudinal velocity distributions along the tunnels for cases 2 and 3.</p

Grid around the tunnel entrance.

<p>Grid around the tunnel entrance.</p

Time histories of the velocity components for cases 1–3 at two positions.

<p>(a) <i>X</i> = 25 m, <i>Y</i> = 5.5 m, and <i>Z</i> = 1.85 m; (b) <i>X</i> = 300 m, <i>Y</i> = 5.5 m, and <i>Z</i> = 1.85 m.</p

Parameters for each calculation case.

<p>Parameters for each calculation case.</p

Peak values of the longitudinal velocities along the tunnel for cases 1–3.

<p>Peak values of the longitudinal velocities along the tunnel for cases 1–3.</p

Contour of the tunnel cross-section.

<p>Contour of the tunnel cross-section.</p