EXPERIMENTAL PERFORMANCE AND COMPARISON OF PERFORMANCE PREDICTION METHODS FOR A TROCHOIDAL PROPELLER MODEL

A three-bladed, 150 mm orbit diameter model trochoidal propeller was tested at atmospheric pressure in a cavitation tunnel. The tests included forward propeller operations at rotational speeds of 150 and 200 rpm and bollard pull tests at speeds from 100 to 200 rpm. Results are presented of thrust and torque coefficient and propulsive efficiency over a range of advance ratio. Results from two theoretical analysis methods for cycloidal propellers were compared with particular emphasis on their effectiveness in predicting performance of this trochoidal propeller. Mendenhall and Spangler's discrete vortex method for cycloidal propeller performance was modified to: a) calculate the angle of attack changes at each propeller blade directly from the induced velocities due to all vortices in the flow representing the wake and other blades; b) calculate lift and drag on the blades from various models and experimental section data; and c) include an approximate model for stall hysteresis of a blade section operating into and out of stall (dynamic stall). Multiple streamtube momentum theory was used with experimental blade section data. Results show that both methods predict the global induced velocities of the propeller at the blades to similar levels of accuracy. However the accuracy of performance prediction is limited because: a. the methods do not adequately calculate the three dimensional performance of the blades in unsteady flow below stall; and b. the performance of the blade section in three dimensional unsteady flows through and above stall is unknown.

  • Supplemental Notes:
    • Intl Shipbuilding Progress, v 41 n 426, July 1994, p 113 [24 p, 24 ref, 16 fig]
  • Authors:
    • Riijarvi, T
    • Mun, J L
  • Publication Date: 1994

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00716161
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Feb 28 1996 12:00AM