基于第三代涡识别方法的极地邮轮自航流场中的涡结构分析

Identification of Vortex Structure in Flow of Self-propelled Polar Cruise Ship Based on the Third Generation Vortex Identification Method

在船舶航时产生的流场中,涡结构是无处不在的。自2017年兴起的Liutex方法对流体的局部刚体旋转进行了详细阐释,其中包括局部旋转轴和旋转强度,据此,涡量可分解为刚体旋转和纯剪切,可从流体运动中提取出刚体的旋转部分。对于不同的研究对象,第三代涡识别方法Liutex无需调整阈值,此外,ΩR方法还可识别强度不同的涡结构;通过使用Liutex方法,可以较为准确地描述各种涡的重要特征量,如涡核中心、涡流边界及绝对强度等。该文通过使用不同的涡识别方法,分析了极地邮轮自航流场中船体、舵周围以及旋转螺旋桨所产生的涡结构。

Vortex structures are common when ships pass by.The Liutex method,which emerged in 2017,can show us the local rigid body rotation of the fluid,including the local rotation axis and rotation intensity,according to which the vorticity can be decomposed into rigid body rotation and pure shear,so that the rotating part of the rigid body can be extracted from the fluid motion.The third-generation vortex identification method does not need to adjust the threshold,and in addition,ΩR method can also identify vortex structures with different intensities.By using the Liutex method,various important feature quantities of vortices can be described more accurately,such as vortex core,vortex center,eddy boundaries,absolute intensity,etc.In the paper,by using different vortex identification method,the vortex structure generated by the hull,rudder and the rotating propeller of the self-propelled polar cruise ship is analyzed.