| Summary: | A method is presented for predicting full-scale ship powering performance from model load-varying testdata. The method follows the recommendations for powering prediction of the Specialist Committee onUnconventional Propulsors of the 22nd IITC: specifically, that ship models fitted with unconventionalpropulsors should be tested as a unit and not broken down into component tests of hull, propulsor, rotorand stator components, and that extrapolation of full scale powering should be done using self propulsionload varying tests of the geometrically similar ship model and geometrically similar propulsor. Values of aform factor, a resistance and a thrust deduction fraction are found from an analysis of the under/overloadtests. The full scale torque and thrust coefficients are estimated from the model propeller data in thebehind condition. Results are presented for a conventional twin screw icebreaker for which self-propulsiondata and full scale trials results were available. Comparisons are made between the results and anextrapolation done using the IITC 1978 method. The effects of using different friction lines are discussedand included in the analysis. A discussion of the choice of appropriate correlation coefficients is included.
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