基于降低航行阻力的声呐导流罩外形优化

Numerical optimization of sonar dome profile based on reducing its sailing resistance

导流罩突出于主船体的底部或首部之外,可以明显降低水流对声呐探测性能的影响,但在一定程度上增大了航行阻力。本文通过数值方法研究某Ⅰ型船加装导流罩前后航行阻力的变化及导流罩对船速的影响。研究表明,加装导流罩后船底的最大压力和船的航行阻力有所增大,但由于导流罩的排水体积与整个船舶的排水体积相比要小得多,因此加装导流罩对船速影响不明显。为优化导流罩的外形结构和进一步降低航行阻力,提出了4种导流罩外形模型并对其流体动力学性能进行分析。对比结果表明,导流罩外形结构为头部流线型、尾部半圆型的综合性能最佳。

Owing to protruding from the hull bottom or the head of a ship, sonar dome can significantly reduce influence of water flow on detecting objective performance of sonar, while at the same time it increase sailing resistance to some extent. In the present thesis, sailing of a ship with or without installing sonar dome was numerically studied. The research focuses on changing of sailing resistance and influence of sonar dome on sailing speed. The numerical results show that the maximum pressure of the bottom of the ship and sailing resistance are all increased after installing the sonar dome. Due to the drainage volume of the sonar dome much smaller than that of the whole ship, the impact of installing sonar dome on sailing speed is not evident. In order to optimize profile of the sonar dome and further reduce its sailing resistance, four kinds profile structure of sonar dome were proposed and their fluid dynamics performances were discussed. The compared results show that the comprehensive performance of the dome profile with its head streamline and tail for semi-circular is the best.