In this paper, several commonly used vortex identification methods for marine hydrodynamics are revisited. In order to extract and analyse the vortical structures in marine hydrodynamics, the Q, λ₂ — criterion and modified normalized Liutex/Rortex \(\it {\tilde\Omega_R}\) method are utilized for vortex identification for propeller open water test, ship drag test, ship propeller-rudder interaction, VIV of a marine riser and VIM of a Spar platform. The limitation of Q and λ₂ — criterion is discussed. The Liutex/Rortex \(\it {\tilde\Omega_R}\) method is promising for convenient and accurate vortex identification and visualization. However, care should be taken when choosing the small parameter b₀ for \(\it {\tilde\Omega_R}\). We proposed recommended values of b₀ for marine hydrodynamic problems.

中文翻译：

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海洋流体动力学中的涡旋识别方法

本文讨论了几种常用的海洋流体动力学涡旋识别方法。为了提取和分析在海洋流体动力学旋涡结构中，Q，λ ₂ -标准和改进的归Liutex / Rortex \（\它{\代字号\ Omega_R} \）方法被用于涡旋识别为螺旋桨打开水试验，船舶阻力测试，船舶螺旋桨/舵相互作用，船用立管的VIV和Spar平台的VIM。的限制Q和λ ₂ -标准进行了讨论。Liutex / Rortex \（\ it {\ tilde \ Omega_R} \）该方法有望实现方便，准确的涡流识别和可视化。但是，在为\（\ it {\ tilde \ Omega_R} \）选择小参数b ₀时应小心。对于海洋流体动力学问题，我们提出了建议的b ₀值。