Accession Number : AD0688785

Title :   NOTES ON SHIP MODEL TESTING IN TRANSIENT WAVES.

Descriptive Note : Research and development rept.,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER WASHINGTON D C HYDROMECHANICS LAB

Personal Author(s) : Gersten,Alvin ; Johnson,Robert J.

Report Date : APR 1969

Pagination or Media Count : 49

Abstract : Ship model experiments were conducted to evaluate the accuracy of motion transfer functions obtained by means of the transient wave technique. Since such an evaluation was especially needed for higher ship speeds, Froude numbers up to 0.35 were investigated. Also studied was the feasibility of measuring the incoming wave train far ahead of the model, where distortion of the forcing function by model-generated waves cannot occur. Further, in the interest of reducing computer usage time, the effect of sampling rate on the analysis of analog signals obtained during transient wave tests was examined. Results are also presented which demonstrate a need for smoothing the 'raw' spectra obtained from the computation of Fourier transformations, in order to provide consistently useful transfer functions. (Author)

Descriptors :   (*MODEL BASINS, HYDRODYNAMICS), (*WATER WAVES, MOTION), VELOCITY, DISTORTION, MEASUREMENT, SHIP MODELS, FOURIER ANALYSIS, DATA PROCESSING, TEST METHODS, NAVAL RESEARCH

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE