A THEORETICAL AND EXPERIMENTAL INVESTIGATION OF FLAPPED RUDDERS

Two flapped rudders with .10 and .20 flap areas of a typical high speed vessel were examined experimentally in a water tunnel, in free stream, and behind a propeller. Effects of rudder geometry are discussed in detail, in particular, effects of taper ratio, thickness, sweep angle, and flap size. A lifting surface program was written and used in order to compare and choose the best rudder planform. Results include free-stream coefficients of lift, drag, moment and flap moment, for a wide range of angles of attack and flap deflection angles. Effects of variations in propeller-rudder axial clearance was examined. Presented is a discussion of effects caused by viscosity, gaps, and wall interaction. Comparison was made with the performance of other flapped rudders. A rudder with 20 percent flap was selected as one having the best performance characteristics. A strong effect of propeller wake on rudder characteristics was observed. Independence of rudder forces on axial clearance between propeller and rudder was noticed.

  • Corporate Authors:

    Massachusetts Institute of Technology

    Department of Ocean Engineering, 77 Massachusetts Avenue
    Cambridge, MA  USA  02139
  • Authors:
    • Oppenheim, B M
  • Publication Date: 1974-12

Subject/Index Terms

Filing Info

  • Accession Number: 00057478
  • Record Type: Publication
  • Source Agency: Massachusetts Institute of Technology
  • Report/Paper Numbers: Thesis
  • Files: TRIS
  • Created Date: Oct 22 1974 12:00AM