The resistance and flow field characteristics of moonpool and its improvement forms

ZHAN Xingyu1，MAO Xiaofei*1，2 1 School of Transportation，Wuhan University of Technology，Wuhan 430063，China 2 Key Laboratory of High Performance Ship Technology of Ministry of Education， Wuhan University of Technology，Wuhan 430063，China moonpool is a type of opening structure through the hull from deck to bottom, but it often brings adverse impacts on the performance of resistance due to its complex flow.［Methods］ The computational fluid dynamics（CFD） method was utilized to perform numerical simulations of resistance and flow field of a ship with moonpool in still water. Meanwhile，the resistance performance of two typical modified moonpools，recess type and corner-cutting type，was verified and the improvement mechanism of resistance increase was studied.［Results］The total resistance of the ship increases by 51% with the setting of moonpool，and the moonpool resistance is close to the great increment of pressure resistance. The maximum reductions of added moonpool resistance can separately reach 80% and 40% by the recess type and corner-cutting type moonpools. And the flow details show the process of vortex motions in the flow field，the law of resistance increase caused by moonpool and the improvement mechanism of added moonpool resistance by the modified moonpools.［Conclusions］The resistance variation is closely related to the periodic vortex motions in the flow field，which differs in different speeds. Moreover，the recess type moonpool increases the damping of fluid motions and the corner-cutting type moonpool alleviates the strong effect of the vortex on the back wall of moonpool therefore the modified types are able to reduce the increased resistance induced by moonpool. method；still water resistance；flow field analysis；vortex motion

Abstract：［Objectives］The words：moonpool；CFD Key