Evaluation of the slipstream in different regions around a train with respect to different nose lengths: A comparison study

Abstract

In this work, the flow surrounding the train was obtained using a detached eddy simulation (DES) for slipstream analysis. Two different streamlined nose lengths were investigated: a short nose (4 m) and a long nose (9 m). The time-average slipstream velocity and the time-average slipstream pressure along the car bodies were compared and explained in detail. In addition to the time-averaged values, the maximum velocities and the pressure peak-to-peak values around the two trains were analyzed. The result showed that the nose length affected the slipstream velocity along the entire train length at the lower and upper regions of the side of the train. However, no significant effect was recognized at the middle height of the train along its length, except in the nose region. Moreover, within the train’s side regions (y=2.0–2.5 m and z=2–4 m) and (y=2.5–3.5 m and z=0.2–0.7 m), the ratio of slipstream velocity U _max between the short and long nose trains was notably higher. This occurrence also manifested at the train’s upper section, specifically where y=0–2.5 m and z=4.2–5.0 m. Similarly, regarding the ratio of maximum pressure peak-to-peak values Cp – p _max, significant regions were observed at the train’s side (y=1.8–2.6 m and z=1–4 m) and above the train (y=0–2 m and z=3.9–4.8 m).

Keywords

high-speed train / nose length / slipstream velocity / pressure change

References

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