Accession Number : AD0427833


Title :   BLADE FREQUENCY HARMONIC CONTENT OF THE POTENTIAL WAKE OF SINGLE SCREW SHIPS,


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


Personal Author(s) : Breslin,J P ; Odenbrett,C L


Report Date : Apr 1963


Pagination or Media Count : 1


Abstract : Using thin ship theory, approximate formulas are developed for the axial velocity at the propeller plane. Harmonic analysis of the flow variation at one radius is carried out to provide the harmonic content at the propeller plane of U- and V-sectioned hull forms and a strut of infinite draft for which the exact solution is known. These results are compared with the harmonic content obtained from experimental model data. The potential wake harmonics are compared with those obtained from model tests and are found to be much smaller. An estimate is made of the harmonic content of the viscous wake. Vibratory thrust computations for a specific propeller, using the wake velocities of the U- and V-sectioned hull forms, are included. It is concluded that the potential flow contribution to the harmonic content of the flow at the propeller plane and the resultant vibratory thrust is of an order of magnitude smaller than that which arises from viscous effects. (Author)


Descriptors :   *WAKE , *MARINE PROPELLERS , HARMONIC ANALYSIS , SHIPS , VELOCITY , PROPELLER BLADES , THRUST , TORQUE , FLUID FLOW , MATHEMATICAL MODELS , PERTURBATION THEORY , BESSEL FUNCTIONS , SHIP HULLS , VIBRATION , VISCOSITY , HYDRODYNAMICS , BOUNDARY LAYER


Distribution Statement : APPROVED FOR PUBLIC RELEASE