LAUSR

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, λ 2 — criterion and modified normalized Liutex/Rortex $$\it {\tilde\Omega_R}$$ Ω ~ 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 λ 2 — criterion is discussed. The Liutex/Rortex $$\it {\tilde\Omega_R}$$ Ω ~ R method is promising for convenient and accurate vortex identification and visualization. However, care should be taken when choosing the small parameter b 0 for $$\it {\tilde\Omega_R}$$ Ω ~ R . We proposed recommended values of b 0 for marine hydrodynamic problems.