层冰边界条件下多气泡破冰试验研究

Experimental study on multi-bubble ice breaking under layered ice boundary condition

为提高破冰船的破冰能力,探究气泡运动状态和特征参数对层冰的影响规律,在一定的气泡间距和气泡与层冰距离条件下,通过超高速摄像机研究在层冰下方布置单个气泡、水平布置2个气泡、垂直布置2个气泡的运动状态、半径变化及其破冰效果。研究结果表明:带孔层冰下方布置单个气泡时,气泡塌陷后形成冲击波,在层冰的上、下表面形成膨胀波和压缩波,导致层冰自上向下破裂;无孔层冰下方水平布置2个距离过近的气泡,相互融合后坍塌,形成斜射流后释放冲击波,传播到层冰的上、下表面,导致层冰自下向上破裂;带孔层冰下方水平布置2个距离较近的气泡时,气泡融合后坍塌,形成朝下的斜射流,射流碰撞后形成冲击波,导致层冰自下向上破裂;带孔层冰下方垂直布置2个距离较近的气泡时,气泡相互融合后收缩,形成向下的射流,射流碰撞产生水锤效应,产生冲击波传播到层冰表面产生反射波,导致层冰自下向上破裂。气泡与带孔层冰相互作用的破冰效果弱于无孔层冰。

To enhance the icebreaking capability of an icebreaker,the influence of the bubble motion state and characteristic parameters on ice blocks is investigated.Under specific conditions of bubble spacing and distance between bubbles and ice sheets,the motion states,radius changes,and icebreaking effects of arranging a single bubble,horizontally arranging two bubbles,and vertically arranging two bubbles below the ice sheet are studied using a high-speed camera.The research results show that when a single bubble is arranged below a perforated ice block,the collapse of the bubble forms a shock wave,creating expansion and compression waves on the upper and lower surfaces of the ice block,causing it to rupture from top to bottom.Placing two bubbles horizontally beneath a solid ice block too close together results in their collapse after merging,forming an oblique jet flow that releases a shock wave,which propagates to the upper and lower surfaces of the ice block,causing it to rupture from bottom to top.When two bubbles are placed horizontally below a perforated ice block at a relatively close distance,their merging and collapse create a downward oblique jet flow to form shock waves,causing the ice block to rupture from bottom to top.Placing two bubbles vertically below a perforated ice block at a close distance results in their mutual merging and contraction,creating a downward jet flow to generate a water hammer effect,producing shock waves that propagate to the ice block′s surface,leading to its rupture from bottom to top.The icebreaking effect of bubbles interacting with perforated ice sheets is weaker than that of non-perforated ice sheets.