LOW FREQUENCY VARIATION OF THE SURFACE OF TIP REGION CAVITATION ON MARINE PROPELLER BLADES AND CORRESPONDING DISTURBANCES ON NEARBY SOLID BOUNDARIES

Two features are considered in this paper: The effectiveness of the apparent volumes of water/cavitation-bubble mixture on and near to heavily loaded blades in inducing fluctuating pressure on near and far field solid boundaries. Cavitating bubbles may travel from the tip region of heavily loaded blades to nearby solid boundaries causing severe erosion and excitation of vibrations. Use has been made of high speed cameras, TV equipment and photogrammetry to provide basis for a "macro-type" of analysis of the highly complex phenomena indicated above. The accuracy of the photogrammetric methods seems adequate for full scale tests. Exposure time i.e. radial-tangential motion of mixture may constitute a general difficulty for model work. A simple transfer function is developed, which relates volumes in translating motion (with moving surface) to nearby and far field-velocity potential of low frequency. The effectiveness of mixture downstream of separation region on blade tip region--in causing disturbances in water--is briefly considered.

• Corporate Authors:

  Royal Norwegian Council for Scientific & Indus Res

  Radhusgaten 8, Sentrum
  Oslo,   Norway 
• Authors:
  • Sontvedt, T
  • Frivold, H
• Publication Date: 1976

Media Info

• Features: References;
• Pagination: p. 2-14
• Serial:
  • Norwegian Maritime Research
  • Volume: 4
  • Issue Number: 2
  • Publisher: Royal Norwegian Council for Scientific & Indus Res

Subject/Index Terms

• TRT Terms: Cavitation (Mechanics); Cavitation erosion; Propellers; Transfer functions; Vibration
• Subject Areas: Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00152483
• Record Type: Publication
• Source Agency: Engineering Index
• Files: TRIS
• Created Date: Apr 27 1977 12:00AM