Accession Number : AD0700944

Title :   A THEORY FOR THE PROPELLER-RUDDER INTERACTION.

Descriptive Note : Final rept.,

Corporate Author : STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB

Personal Author(s) : Tsakonas,S. ; Jacobs,W. R. ; Ali,M. R.

Report Date : AUG 1968

Pagination or Media Count : 107

Abstract : The propeller-rudder interaction problem is studied by means of the unsteady lifting-surface theory. Both surfaces of arbitrary geometry are immersed in a nonuniform flowfield (i.e., hull wake) of an ideal incompressible fluid. The boundary-value problem yields a pair of surface integral equations, the inversion of which is achieved by the so-called 'generalized lift operator' technique, a new approach developed by the authors, in conjunction with the presently used 'mode-collocation' method. The analysis demonstrates the mechanism of the interaction phenomenon by exhibiting the filtering effects of the propeller on the harmonic constituents of the wake which allow the rudder to be exposed only to the blade harmonic and multiples thereof. A numerical procedure adaptable to the CDC 6600 computer was developed which furnishes information about (1) the steady and time-dependent pressure distribution on both lifting surfaces, and (2) the resultant hydrodynamic force and moments. A limited number of calculations exhibits the importance of some parameters such as axial clearance, number of blades, and harmonic components of the hull wake. (Author)

Descriptors :   (*MARINE RUDDERS, INTERACTIONS), (*PROPELLERS(MARINE), HYDRODYNAMICS), INTERFERENCE, LIFT, VIBRATION, PROPELLER BLADES, SHIP HULLS, WAKE, INTEGRAL EQUATIONS, THEORY

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE