Contribution of higher-order harmonics for estimating manoeuvring derivatives from oscillatory tests

Article type: Research Article

Authors: Sutulo, S. | Guedes Soares, C.

Affiliations: Unit of Marine Technology and Engineering, Technical University of Lisbon, Instituto Superior Técnico, Lisbon, Portugal

Note: [] Corresponding author. E-mail: guedess@mar.ist.utl.pt.

Abstract: The process of estimation of manoeuvring derivatives from oscillatory captive model tests is analyzed and it is demonstrated that, contrary to common belief, all important information concerning quasi-steady force components can be extracted by means of only two terms of the Fourier expansions of the output time histories of force measurements: the mean values and the first-order out-of-phase coefficient values. Additional involvement of the second-order coefficients does not alter substantially the estimates of the regression coefficients and in most cases does not make the resulting regression model more certain and accurate, as shown with an example.

Journal: International Shipbuilding Progress, vol. 54, no. 1, pp. 1-24, 2007