THE EFFECT OF AIR COMPRESSIBILITY ON THE NONLINEAR MOTION OF AN AIR CUSHION VEHICLE OVER THE WAVES

The nonlinear behavior of an air-cushion vehicle (ACV) during coupled heave and pitch motion over a sinusoidal water wave is studied. The compressibility of the air flow within the vehicle is considered in addition to the previously-studied effect of the waves generated by the pressure distribution under the craft. The ACV studied is of the plenum-chamber type with a transverse stability skirt. Linearized potential-flow theory is used to compute the waves generated by the craft. The effect of compressibility is assumed to occur principally in an accumulation of the air within the vehicle compartments. Numerical computations were made to determine the response of a typical ACV to regular head waves. Nonlinearity with respect to wave height is particularly evident at a Froude number of 1.5 and a dimensionless encounter frequency of 9. For the same conditions, the heave and pitch motions were reduced by up to 20% from the hydrodynamic effect. However, the motion could be increased by 50% or more for a craft of length 40 m, when compressibility were accounted for.

  • Supplemental Notes:
    • Prepared for presentation at the Eleventh Symposium on Naval Hydrodynamics, London, England, March 28-April 2, 1976.
  • Corporate Authors:

    University of New South Wales

    School of Mechanical and Industrial Engineering
    Kensington, New South Wales  Australia  2033
  • Authors:
    • Doctors, L J
  • Publication Date: 1976-1

Media Info

  • Features: References;
  • Pagination: 16 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00139684
  • Record Type: Publication
  • Source Agency: University of New South Wales
  • Report/Paper Numbers: NAV/ARCH 76/1
  • Files: TRIS
  • Created Date: Sep 16 1976 12:00AM