Propulsion and forward bollard pull tests were made for two coastal vessel models fitted with ducted propellers. The duct section shapes were of new type geometry described in preceding reports. The complete propulsor was investigated in two alternative locations, in the original one designated as the 'reference location', and in the 'aft location', where the complete propulsor was shifted aft by the amount of about 0.17*(duct chord). The propulsive performance in the aft location was better by about one to four percent for both vessels because of their rather full hull form. This is in agreement with published propulsion model test results of tankers of large block coefficient. The bollard pull tests were made at the even keel and at several forward trim conditions. The purpose of the trim was to simulate a smaller draft. The merit coefficient based on the pull force was better for the aft locations. At the aft locations the propulsor started to draw air at smaller forward trim angles than at the reference location. The shallow semi-tunnel of one of the models gave good protection against drawing air into the duct.
Influence of Nozzle Shape and Propeller Location on the Propulsion of Two Ships with Ducted Propeller
1992
32 pages
Report
No indication
English
The Influence of Nozzle Shape and Propeller Location on the Performance of a Ducted Propeller
British Library Conference Proceedings | 1992
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