A numerical investigation of sinkage and trim effects on the resistance of trimaran hull form in calm water
(2.School of Naval Architecture Engineering, Dalian University of Technology, Dalian, China 116024)
(3.State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian, China 116024)
(4.Liaoning Engineering Laboratory for Deep-Sea Floating Structures, Dalian, China 116024)
【Abstract】 ObjectivesThe navigation attitudes (sinkage and trim) of a semi-planing ship (at Froude number Fr> 0.4) have significant effects on its resistance performance during the voyage. The sinkage and trim effects on the resistance components (frictional resistance and pressure resistance) are discussed.MethodsA CFD study is carried out on the resistance performance of a trimaran in calm water, and the k-ε turbulent model and overlapping grids are adopted. The free model and constrained model are computed. The computed results are compared to analyze the effects of sinkage and trim on the resistance components. ResultsThe results show that the change in total resistance caused by sinkage and trim is more than 20% in semi-planing conditions. The sinkage and trim have a significant effect on the pressure resistance, up to nearly 50%, and a relatively small effect on frictional resistance, less than 8.5%. More than 90% of the resistance increase caused by motion attitude comes from the change in pressure resistance.ConclusionsPredicting the motion attitudes and resulting pressure resistance changes accurately is extremely important for a semi-planing trimaran.
【Keywords】 semi-planing; trimaran; resistance; sinkage and trim;
(Translated by HAN R)
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