Accession Number : AD0265193

Title :   ON THE CALCULATION OF THRUST AND TORQUE FLUCTUATIONS OF PROPELLERS IN NONUNIFORM WAKE FLOW

Corporate Author : DAVID TAYLOR MODEL BASIN WASHINGTON D C

Personal Author(s) : McCarthy,Justin H.

Report Date : OCT 1961

Pagination or Media Count : 41

Abstract : The general phenomenon of propeller thrust and torque fluctuations in the behind condition is discussed. Mention is made of published methods of calculating these fluctuations and of some experimentally measured values. Following, the effects of wake distribution, number of blades, propeller skew, load distribution, and stern ARRANGEMENT ARE CONSIDERED IN RELATION TO INSTANTANEOUS THRUST AND TORQUE ABSORBED BY A PROPELLER. A short method for the calculation of quasi-steady-state propeller thrust and torque fluctuations is then outlined. The method of calculation is applied to several examples and the results are compared with those given by other methods of calculation and with experimental results. Comparison indicates that the short method presented predicts thrust and torque fluctuations which are in generally good agreement with experimental results for the cases examined. (Author)

Descriptors :   *FLUID FLOW, *MARINE PROPELLERS, *THRUST, *TORQUE, *WAKE, EXPERIMENTAL DATA, HARMONIC ANALYSIS, LOAD DISTRIBUTION, MODEL BASINS, MODEL TESTS, NAVAL RESEARCH LABORATORIES, PITCH(MATERIAL), PITCH(MOTION), PROPELLER BLADES, SHIPS, VELOCITY, VORTICES.

Distribution Statement : APPROVED FOR PUBLIC RELEASE