Modelling the response of a standing person to the slipstream generated by a passenger train

Abstract

This article develops two relatively simple models that are combined in order to model the response of a standing person to a passing train. The first model combines potential flow theory, boundary layer theory, and autoregressive modelling in order to simulate the slipstream of a passenger train. The second moment simulates the response of a person to the wind velocities generated in the slipstream model. For the first 0.375 s the person is assumed to respond as a solid object, whereas after this time a spring-mass-damper system is used to represent the response of a person. A Monte Carlo analysis is used in order to establish the probability of a person becoming destabilized as a result of increasing train speed. Finally, a parametric analysis is undertaken and illustrates that the output of the models that represent the response of a person is sensitive to the parameter values chosen.These measurements are complicated further since platform height in Europe can vary between countries. Currently, HS RST TSI [3] imposes two limits on the slipstream induced velocities.

Experimental investigation of the slipstream development around a container freight train using a moving model facility

“…In this study, close to the train side (1.75 m from the centre of track (probe 1)), a nose peak of magnitude 120% in U extending 10 m has been found. For a train speed V train ¼ 20 m/s the 10 m peak extents relate to a time scale of 0.5 s, beyond the suggested range to create passenger instability (Sterling et al, 2008;Jordan et al, 2009). However, at full UK freight speed of 33.5 m/s this relates to a time scale of 0.3 s, which coupled with a peak magnitude of 120% could potentially cause passenger instability.…”

The Aerodynamics of a Container Freight Train

“…Understanding slipstream development allows appropriate safety guidelines to be published. Current safety measures include announcements of oncoming trains, platform warning signs and yellow lines indicating a safe distance from which to stand behind as an oncoming non-stopping train approaches Jordan et al, 2009). …”

“…Research focused on key flow regions has allowed an understanding of the fundamental nature of flow within these regions to be developed in recent years (Sanz-Andrés et al, 2003;Jordan et al, 2009;Baker et al, , 2013a.…”

“…In this study, close to the train side (probe 2) a nose peak of magnitude 120% in U extending 10m has been found. At train speed 20m/s this relates to a time scale of 0.5s, beyond the range of creating passenger instability Jordan et al, 2009). However, it will be shown in section 5.7 that the nose peak extents and normalised magnitudes remain relatively constant as train speed is increased, highlighting Reynolds number independence.…”

“…A slipstream extends from upstream of the train nose into the wake beyond the train tail. Slipstreams associated with high speed trains can create highly turbulent nonstationary air flows, with pressure and velocity magnitudes capable of interacting and potentially destabilising trackside objects and people (Jordan et al, 2009). However, slipstream magnitudes are highly dependent on train type, speed, and the distance from the train side.…”