MEASUREMENT OF PRESSURE DISTRIBUTION ON A FULL SCALE PROPELLER - MEASUREMENT ON A CONVENTIONAL PROPELLER

This paper describes the development of a sophisticated pressure measurement technique for a full scale propeller and the success of the measurement. First of all, the special pressure pick-ups with Helmholtz chamber were designed. The full scale measurements were carried out on the training ship SEIUN-MARU. Six pressure pick-ups were equipped at each of four propeller blades. The pressure signals were transmitted from the pressure pick-ups on the propeller blades through slip-rings to FM receivers and analysed using static pressure calibration data obtained in the sock before the voyage. This ship was operated so carefully that the working conditions at each propeller revolution rate were kept constant, that is, Kr=0.210. Then, the measured non-dimensionalised pressure distributions were similar at each condition, except cavitation regions. Except the lowest revolution rate, sheet cavitation or tip vortex cavitation was observed and the influence of cavitation of other blades on the pressure measurement was found out. The present measurement techniques have the accuracy of plus or minus 0.03 kg/cm2. By the pressure coefficient, it amounts to plus or minus 0.3 at 70 RPM and plus or minus 0.7 at 140 RPM, respectively. The measured pressure distributions were compared with the theoretical ones obtained by the existing lifting surface theory. In this calculation, the estimated nominal wake distribution was employed, including the tangential wake based on the measurement in a towing tank. Excellent agreements with theory were found at most of the measurement points, especially the fore part of the blades. These results clearly demonstrate that the use of this estimated wake and the lifting surface theory with the concept of the equivalent two-dimensional profile is quite reasonable for a conventional propeller principally. Near the angular position of the top, some discrepancies between the measurements and theory were observed probably due to the deformation of the nominal wake and the leading edge separation. The present full scale measurements indicated that there still exist some problems on the lifting-surface theory and the use of nominal wake. These measurements also confirmed that the measured pressure in the sheet cavitation region was nearly equivalent to the vapour pressure at each working condition. The study has provided a number of invaluable standard data to validate the numerical computational techniques on marine propellers at high Reynolds number.

• Supplemental Notes:
  • Soc Naval Arch Japan J, v 168 n 2, Dec 1990, p 65 [11 p, 11 ref, 3 tab, 12 fig]
• Authors:
  • Ukon, Y
  • Kudo, T
• Publication Date: 1990

Language

• Japanese

Subject/Index Terms

• TRT Terms: Instruments for measuring loads or pressure; Measurement; Pressure; Propellers
• Uncontrolled Terms: Pressure distribution
• Old TRIS Terms: Pressure measurement; Seiun-maru
• Subject Areas: Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00716290
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Feb 28 1996 12:00AM