The harmonic heave and pitch motion of an air-cushion vehicle traveling at a constant speed over water is studied here, with a view to determining the power radiated by the surrounding wave system. The planform of the particular craft considered is compartmented into forward and aft subcushions, and the fluctuations of pressure in these are utilized to represent the effect of the vehicle on the water. The usual linearized incompressible potential flow theory is used. The calculations show that at typical Froude numbers and encounter frequencies, considerable power can be radiated in this manner, and it is generally of similar magnitude to the power required to overcome the usual steady-state wave resistance. Surprisingly, the singularity in the linear theory that occurs at the critical speed-frequency condition was found to be extremely localized and is therefore only significant in the case of a two-dimensional pressure band, or in the case of a three-dimensional pressure patch, at low Froude numbers.

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  • Corporate Authors:

    Society of Naval Architects and Marine Engineers

    601 Pavonia Avenue
    Jersey City, NJ  United States  07306-2907
  • Authors:
    • Doctors, L J
  • Publication Date: 1978-6

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Filing Info

  • Accession Number: 00178889
  • Record Type: Publication
  • Source Agency: Society of Naval Architects and Marine Engineers
  • Files: TRIS
  • Created Date: Jul 29 1978 12:00AM