新型动力安装锚水动力学特性模型试验研究

相比于已有动力锚(鱼雷锚、多向受荷锚等),新型轻质动力安装锚借助助推器安装,具有质量轻、埋深大、承载效率高、在海床中下潜容易等特点。良好的水动力学特性(较小的拖曳阻力系数及稳定的下落垂直度)是确保动力安装锚准确、有效地安装到指定地点并贯入到设计深度的前提。通过4组10个工况的模型试验,研究了轻质动力安装锚的终端速度和拖曳阻力系数,及轻质动力安装锚和助推器的组合锚在水中自由下落时的方向稳定性。试验结果表明:优化后轻质动力安装锚的拖曳阻力系数为0.51~0.55,这有助于提高组合锚在水中的下落速度,从而提升组合锚的沉贯深度;增大助推器尾翼展弦比和选用轻质材料制作尾翼能减小组合锚的下落偏角,提高组合锚的方向稳定性。

Experimental investigation on hydrodynamic characteristics of light-weight gravity installed plate anchor

Compared with existing dynamically installed anchors (i.e. torpedo anchor and OMNI-Max anchor), the light-weight gravity installed anchor (L-GIPLA), which is installed by the aid of a booster, owns the advantages of light weight, high penetration depth, high ratio of capacity-to-weight, and diving behaviour in the seabed. Well hydrodynamic characteristics (relatively low drag coefficient, and favourable verticality during free fall in water) are key factors affecting the accurate and effective installation of the dynamically installed anchor to a predesigned position and to a designed embedment depth. In the current study, four groups of model tests, including 10 cases, were conducted. First, the corresponding drag coefficient and the terminal velocity of the L-GIPLA were investigated, and then the directional stability of the hybrid anchor (i.e. booster and L-GIPLA) was investigated. The testing results indicate that the drag coefficient of the optimized L-GIPLA is in the range of 0.51~0.55, which is beneficial in increasing the fall velocity and the embedment depth of the hybrid anchor. To reduce the tilt angle and hence to improve the directional stability of the hybrid anchor, it is necessary to enlarge the aspect ratio of rear fins or replace the rear fins with low density.