DYNAMICS OF SIMPLE AIR-SUPPORTED VEHICLES OPERATING OVER IRREGULAR GUIDEWAYS

The simplest appropriate dynamic model for fluid suspensions, a dynamic spring with lead and lag, is used to study the vertical displacement and acceleration of a vehicle moving over a guideway containing deterministic and random irregularities. The analysis is limited to heave motion and to irregularity wavelengths long relative to the suspension length. For any value of lead time constant an optimum lag time constant is shown to exist which minimizes vehicle acceleration and which may be achieved by adjusting the dead volumes in the fluid suspension. The general results are applied to a simple rigid-walled plenum. Relations for acceleration, relative displacement, mass flow and pumping power are presented as functions of cushion geometry, loading, and hover height. The dynamic lead is shown to depend primarily on the vehicle weight and area and to be a primary factor determining maximum acceleration. For typical vehicle weights and sizes it is shown that optimum dynamic lead cannot be physically realized in a simple plenum suspension. Further the results obtained in this simple analysis suggest that it will be very difficult to achieve adequate passenger comfort at HSGT speeds over realistic guideways through use of only primary rigid simple plenum suspensions. (Author)

• Corporate Authors:

  Massachusetts Institute of Technology

  Engineering Projects Laboratory
  Cambridge, MA  United States 
• Authors:
  • Richardson, H H
  • CAPTAIN, K M
  • RIBICH, W A
• Publication Date: 1967-6

Media Info

• Pagination: 55 p.

Subject/Index Terms

• TRT Terms: Aerodynamics; Guideways; Intelligent transportation systems; Suspensions
• Old TRIS Terms: Advanced systems
• Subject Areas: Operations and Traffic Management; Railroads; Terminals and Facilities;

Filing Info

• Accession Number: 00039088
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: DSR-76110-4
• Contract Numbers: C-85-65t
• Files: TRIS
• Created Date: Nov 24 1973 12:00AM