Ship powering prediction from isolated load-varying test data

• Main Authors: Molloy, S, Bose, N
• Format: Conference Object
• Language: English
• Published: University of British Columbia 2001
• Subjects: Biological Sciences; Ecology; Marine and Estuarine Ecology (incl. Marine Ichthyology); Asan; Icebreaker
• Online Access: http://ecite.utas.edu.au/47458

A method for predicting full-scale ship powering performance from model load-varying self-propulsion testdata is presented. The method uses load varying tests in isolation of resistance and/or propeller open watertests. Although presented here for a conventional twin screw icebreaker, the method is being developed asan alternative to conventional lITC 1978 based methods for ships fitted with unconventional propulsors,including those using podded propulsion systems.Values of a form factor, a resistance and a thrust deduction fraction are found from an analysis of theunder/overload tests. The full scale torque and thrust coefficients are estimated from the model propellerdata in the behind condition. The method is illustrated by using model test data for the Canadian R-Classicebreaker for which corresponding full-scale trials results are available. Comparisons are made of theresults with an extrapolation done using the lITC 1978 method. The effects of use of different friction linesare also discussed.