The importance of the fluctuating pressure field is outlined and its relationship to underwater detection and vessel vibration is discussed. The theoretical analysis of the fluctuating field is considered. Experimental data are presented for the duct-surface pressure fluctuations in a model ducted-impeller unit designed as a screw propeller replacement for a 19,000 ton dead-weight ore carrier. These pressures were measured over a range of impeller loadings and under uniform and nonuniform inflow conditions, and were analyzed both spectrally and harmonically. Significant conclusions are that the fluctuating pressure decreases rapidly with distance from the impeller, that only blade frequency harmonics are present in the pressure, and that blade thickness controls the pressure field forward of the impeller. ( Author )

Media Info

  • Pagination: p. 42-56

Subject/Index Terms

  • Subject Areas: Environment; Marine Transportation; Vehicles and Equipment;

Filing Info

  • Accession Number: 00007107
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: DRB Reprint-2995
  • Contract Numbers: 4738( 00 )
  • Files: TRIS
  • Created Date: Dec 22 1971 12:00AM