简介:Fishareabletomakegooduseofvortices.Inacomplexflowfield,manyfishcontinuetomaintainbothefficientcruisingandmaneuverability.Traditionalman-madepropulsionsystemsperformpoorlyincomplexflowfields.Withfish-likepropulsionsystems,itisimportanttopaymoreattentiontocomplexflowfields.Inthispaper,theinfluenceofvorticesonthehydrodynamicperformanceof2-Dflapping-foilswasinvestigated.Theflapping-foilheavedandpitchedundertheinfluenceofinflowvorticesgeneratedbyanoscillatingD-sectioncylinder.Anumericalsimulationwasrunbasedthefinitevolumemethod,usingthecomputationalfluiddynamics(CFD)softwareFLUENTwithReynolds-averagedNavier-Stokes(RANS)equationsapplied.Inaddition,dynamicmeshtechnologyandpostprocessingsystemswerealsofullyused.Thecalculationsshowedfourmodesofinteraction.Thehydrodynamicperformanceofflapping-foilswasanalyzedandtheresultscomparedwithexperimentaldata.Thisvalidatedthenumericalsimulation,confirmingthatflapping-foilscanincreaseefficiencybyabsorbingenergyfrominflowvortices.
简介:国际海事组织(IMO)制定的STCW78/95公约的实施,全方位地影响了航海教育和船员培训,对船员培训的质量提出了更高的要求.为了履行STCW78/95公约,符合ISM规则的要求,提高我国船员的GMDSS专业知识水平和实际操作技能,有效地实施国际海上搜救公约(SAR),确保海上人命的安全,我国积极开展了GMDSS专业培训工作,并取得了一定的成效.但是自GMDSS在海上实施以来,误报警事件屡见不鲜.究其原因,除了现有GMDSS设备本身的缺陷外,还与高级船员对其设备不甚了解和缺乏严格的训练有关.为了保证GMDSS的有效实施,充分发挥其作用,必须加强对高级船员的GMDSS专业培训,切实提高培训质量.