不同浮冰覆盖率下结构物串联入水空泡演化特性试验研究OA

To clarify the influence mechanism of floating ice on cavity evolution during tandem water entry,a series of tandem water entry experiments under different floating ice coverage ratios were conducted using high-speed imaging technology.The tandem water entry processes under ice-free and various floating ice coverage conditions were compared.The cavity evolution process was divided into three stages:expansion,closure,and collapse.The effects of ice coverage ratios on the cavity evolution characteristics were systematically investigated.The results show that floating ice significantly affects both the cavity evolution and dynamic characteristics.It suppresses the axial and radial expansion of the cavity by restricting fluid backflow.As the ice coverage ratio increases,the pressure difference between the inside and outside of the cavity increases,which accelerates cavity closure.In addition,airflow disturbances induced by the trailing body alter the closure process of the cavity generated by the leading body.During the collapse stage,the presence of floating ice intensifies cavity instability,resulting in unstable motion of the leading body.The velocity attenuation of the body exhibits a three-stage characteristic:a rapid decrease during cavity expansion,a slower attenuation during cavity closure,and an accelerated reduction during cavity collapse.A higher floating ice coverage ratio enhances the kinetic energy transfer effect and lead to greater velocity attenuation.Meanwhile,the horizontal displacement of the body is positively correlated with the floating ice coverage ratio.Under ice-free condition,the motion trajectory remains relatively stable,whereas under high ice coverage conditions,frequent collisions increase the horizontal displacement and reduce the motion stability of the bodies.In addition,both the cavity length and its peak value increase with the ice coverage ratio.The present study provides experimental references for the design of trans-media vehicle in ice-covered regions.