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University of Birmingham
Centre for Rail Research and Education
School of Civil Engineering
B15 2TT
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Tel: 0121 414 5055

Moving Model Rig - applications

click here for non-railway applications

Moving model tests underway on experimental rig

The TRAIN rig is one method of carrying out aerodynamic investigations on trains. Its specific advantages are:

    It avoids the uncontrolled ambient conditions and expense associated with full scale tests, and model test geometry can be varied relatively quickly and cheaply
    Unlike conventional wind tunnels and CFD, it can be used to investigate transient phenomena, such as train passing, slipstreams etc.
    It can be used to calibrate/validate computational models of train tunnel pressure transients
    The use of full scale train speeds ensure Mach number similarity when undertaking tests of pressure wave phenomena in tunnels

Typical examples of studies that can be performed include:

    investigations into the effects of cross-winds on train stability
    slipstream studies (at the trackside and on station platforms with and without cross-winds)
    trains passing
    effect of train shape (development of the aerodynamic design of new trains and improvement of existing trains
    determination of train empirical factors for unsteady flow predictions in tunnels
    exploration of methods for the alleviation of transient pressures in tunnels
    investigation of primary wave steepening in tunnels and the development and alleviation of micro-pressure waves

Click here or go to YouTube to see a video of the rig in action!TRAIN rig video

Moving model tests underway on experimental rig

The rig has been used in the past for a range of different types of test:

    Tunnel pressure transients for a variety of types of train
    Aerodynamic design of train noses
    Pressure pulses around trains in the open air
    Ventilation flows in cross passages
    Train slipstream behaviour
    Determination of pressure loss coefficients and friction factors for trains

Some of this work is described in the following papers

  • T Johnson, J Holding, "Better understanding of high speed train slipstream velocities"
  • P. Da Costa, A. Willaime, A. Evangelou T. Johnson, N. Paradot "Model rig measurements for SNCF new tunnel portal designs"
  • T Johnson, S Dalley "1/25 Scale Moving Model Tests for the TRANSAERO Project"
  • T Johnson, G Figura-Hardy (2008) "Comparison of full-scale and model-scale slipstream velocities", World Congress on Rail Research Abstract
  • T Johnson "Measurements of the effect on pressures of a porous tunnel entrance using a moving model rig"
  • C J Baker, S J Dalley, T Johnson, A Quinn, N G Wright (2001) "The slipstream and wake of a high speed train", Proceedings of the Institution of Mechanical Engineers F Journal of Rail and Rapid Transit, 215, 83-99

    Further publications will be added as they become available from the work currently being undertaken in the rig. This includes work on pressures in semi-confined structures, slipstreams around high-speed trains and pressures on vehicles in cross-winds.

    Other applications

    The TRAIN Rig can potentially be used for a wide range of vehicle testing, but is particularly useful where the motion of a body in the vicinity of the ground is being studied. Possible applications include:

      Investigation of road vehicle behaviour in cross winds
      Measurement of road vehicle aerodynamics in confined situations
      Measurements of road vehicle aerodynamics during overtaking and vehicle passing
      Measurement of pollutant dispersion around moving road vehicles in rural and urban geometries
      Investigations of aircraft and wing behaviour in close proximity to a ground plane
      Investigation of the aerodynamics of bluff bodies in proximity and intermittent contact with the ground (sports balls, wind borne debris)

    Please contact us to discuss any ideas you may have for using the rig.