COMMENTS ON WAVE COMPRESSIBILITY AND STATIC COMPRESSIBILITY ON SUBWAY VEHICLE PERFORMANCE

The effects of wave compressibility and static compressibility as they relate to subway vehicle performance are examined. An idealized environment was assumed in which a one dimensional piston moved without friction or leakage through an infinite tube. The equations developed to measure aerodynamic drag are outlined in detail. The total unsteady drag exerted upon a dynamic vehicle was found to include both near field (wave drag) and far field (shock drag) effects. Wave drag effects on a vehicle accelerating in a confined space filled with compressible inviscid fluid were examined. This analysis revealed that shock drag contributed substantially to total drag effects during deceleration (as much as 30%), but that it was of a much lesser importance during acceleration. /UMTA/

• Corporate Authors:

  California Institute of Technology

  Graduate Aeronautical Laboratories
  Pasadena, CA  United States 
• Publication Date: 1971-3

Media Info

• Pagination: 43 p.

Subject/Index Terms

• TRT Terms: Aerodynamics; Compressibility; Compressive strength; Drag; Entropy (Communications); Environmental engineering; Equations of motion; Mathematical analysis; Mathematical methods; Rapid transit cars; Shock waves; Speed; Subways; Tunnels; Urban transportation; Vehicle performance; Wave drag; Wave motion
• Uncontrolled Terms: Compressive properties
• Old TRIS Terms: Applications of mathematics
• Subject Areas: Bridges and other structures; Highways; Planning and Forecasting; Railroads;

Filing Info

• Accession Number: 00039843
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: Intrm Rpt
• Contract Numbers: DOT-UT-290
• Files: NTIS, TRIS
• Created Date: Mar 9 2003 12:00AM