破碎浮冰环境下结构物倾斜入水空泡演化特性实验研究

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中图分类号:O354;TJ012.3 国标学科代码:13025 文献标志码:A
Abstract:Toinvestigate the influenceof thedensityofcrushed iceregiononthecavityevolutionofastructure,anoblique water-entry experiment of the structure was conducted byhigh-speed photography technology under different crushed ice cover densities.Moreover,bycomparing the water-entryprocess oftheoblique structure in varying densities ofcrushed ice cover,the influenceofcrushedicecoverdensityoncavityevolution duringtheoblique water-entryprocessofthestructure was obtained.Results indicate that during the cavity expansion, the presence of crushed ice reduces the cavity diameter by impedingtheoutward expansionof thefluidnear thefreesurface,compared withtheice-freeenvironment.Whenthecavity closes,crushedicealsoimpedes theinwardcontractionof thefreesurfacefluidand prolongs thecavity expansiontime.The augmentationinthetotal volumeofairwithin thecavityresultsina decrementof the pressure diferentialbetweentheinside andoutsideofthecavity,ultimately leading toaretardation inthecavityclosuretime.Inconditions of lowercrushed ice densities,jetspointtotheinteriorof thecavitywhenthecavitycoapses.Asthecoveragedensityofcrushedicegradual increases,the impedance exerted by the crushed ice on the inward contraction of fluid at the free surface progressively intensifies.This enhancedobstruction fromthe crushedice further prolongs thecavityclosure time andconcurrntlyaugments itslengthand maximumdiameter.Besides,underconditionsofhighercrushedicecoverdensities,thecavitywallis wrinkled by the irregular impact of thefluid. As the submerged depth of the structure increases,the cavity undergoes a dep necking underthe influenceof ambient pressure.As thecoverage densityof crushed ice gradually increases,thevelocity of the underwater motion of the structure shows a trend offaster decay compared with those in ice-free environments.
Keywords:crushed floating ice environment; oblique water-entry; water-entryexperiment;cavityevolution;structure
在北极的复杂环境中,全球气候变暖致使海面上存在大量破碎浮冰,破碎浮冰的存在会影响结构物的入水过程。(剩余11464字)