i.           
To find the forces and moments affecting the train
and its effects on comfort and stability. The goal of this project is to
combine the aerodynamic forces that acts on a high speed train with the
dynamics on the trains bogie and coupling. An interesting final result would be
to find how sensitive the dynamics in the train is to varying velocity.

      ii.           
Reducing the Energy
Consumption of Rail Vehicles

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In
Intercity and high speed trains, 60 per cent of the traction effort is lost due
to aerodynamic drag and friction in typical operation cycles. By reducing the
drag by 25 per cent, it is possible to save between 8 – 15 per cent of traction
energy.

1.1  Literature
Review

 

Baker
et al. (2006) and Baker (2010) discussed a number of experimental and numerical
studies on the assessment of the slipstream gusts caused by passing trains in
open field, with and without cross winds. They also described the potential
effects of wind gusts on exposed people. They mentioned that there is a large
variability in experimental data due to different boundary conditions, train
types and complex flow structures induced by a moving train. Three regions
around a train moving in open field were distinguished: the nose region, the
boundary-layer region, and the wake region. Also, these authors highlighted the
development of turbulent gust flows in the near wake for high-speed trains and
in the growing boundary layer of freight trains. These unsteady flows can cause
discomfort or even destabilize people standing alongside the moving train, by
gusts with speed above 15-20 m/s (Baker et al. 2006). Sterling et al. (2008)
analyzed experimental data for high-speed passenger trains and freight trains
in open field. They examined the different flow regimes within the three
regions around a train and, in line with the previously discussed studies,
highlighted the intermittent behavior of the near wake flows. The velocities
were found to be higher in the near wake and the boundary layer regions than in
the nose region of the train. They also mentioned that the boundary layer
development was slightly different between full-scale and reduced-scale
measurements and that this could influence the near wake flow.

Gil
et al. (2008) mentioned considerable run-to-run variability in the measured
data for a 1/25th scale train with 3 carriages moving on a circular track with
speeds of about 5 m/s to 15 m/s. They experimentally showed that higher train
speeds cause higher ratios of slipstream velocity to train speed. However,
Hemida et al. (2010) studied a 1/25 scale model of an ICE train running on a
circular track in an open space using validated LES simulations and showed that
the Reynolds number effect on normalized slipstream velocities is negligible for
trains moving with speeds varying within 20%. Finally, Hemida et al. (2014) in
their LES study investigated the effect of the platform height on the
slipstream velocity. The slipstream velocities that occurred with a higher
platform were increased due to the blocking of the developing slipstream flow.
They also monitored the instantaneous flow in the wake of the train and
confirmed the presence of highly turbulent vorticity. The maximum velocities
and the largest turbulence intensities were observed in the near wake of the
passenger train. 4

1.2  Geometry

 

The
first part of this work is to examine the methodology used for the
computational technique in studying train passing in tunnels. This technique is
based on a moving train in a stationary environment. As part of the Aero TRAIN
project, a generic train has been created that has previously been used to
investigate pressure pulses in a circular tunnel. Figure 1 shows the profile of
the generic train. This profile is described by the following equation;

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