Technical Reports

Aerodynamic Forces on Maglev Vehicles

  • 01
  • Dec
  • 1992
AUTHOR: Federal Railroad Administration; T. Barrows; D. McCullum; S. Mark; R.C. Castellino
OFFICE: RPD
REPORT NUMBER: DOT/FRA/NMI-92/21
SUBJECT: Maglev
ABSTRACT: The results of four separate tasks are documented: (1) minimization of front-end drag, (2) effect of fineness ratio (ratio of length to diameter) on drag, (3) design of aerosurfaces for control purposes, and (4) control and dynamics of maglev vehicles with aerodynamic control surfaces. Task 1 examines the flow disturbances near the nose of a high speed channel vehicle which cause vortices to form near the tops of the guidewalls. These vortices are a major source of drag. The nose of the train can be idealized as a source flow, and the walls of the channel guideway are represented as two vertical flat plates. A numerical solution of the two-dimensional unsteady problem is presented. Using a representative design example, the nose shape which provides the minimum drag is derived from this solution. Under task 2, drag data is presented from the automotive industry, the Japanese National Railway, Krauss-Maffei, and Tracked Hovercraft Limited. An empirical formula is used to estimate the drag of vehicles designed for channel and box beam guideways. The optimum width for these cases is derived. Under task 3, a simple numerical scheme is described for computing the lift and drag on an aerosurface with a control flap operating in close proximity to a guideway surface. It is shown that large variations in lift can be produced using very small flap angles. Task 4 examines the improvement in ride quality (or conversely the increase in allowable guideway roughness for a given ride quality) which is possible through the use of aerodynamic control surfaces. Comparisons are made between vehicles with active and passive secondary suspensions with aerodynamic control surfaces mounted on the vehicle body or control flaps on the vehicle bogies.

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