Application of an anisotropic SST model to complex flow simulations

Objective The flow fields around underwater vehicles are highly complex, making accurate prediction of their hydrodynamic characteristics a significant challenge in computational fluid dynamics. To address this challenge, this study aims to apply and evaluate a turbulence model suitable for numerical simulation and engineering prediction of complex flows.

Method Based on the conventional SST (Shear Stress Transport) turbulence model, an anisotropic SST turbulence model (Anisotropic SST, ASST) is developed and evaluated by introducing nonlinear correction terms into the Reynolds stress formulation. To assess its applicability and predictive capability, systematic numerical validations are performed using several benchmark cases at moderate to high Reynolds numbers (Re = 3.6×10⁴–1.4×10⁷), including backward-facing step flow, the Rood wing–body configuration, the A-airfoil, and the SUBOFF model.

Results The results indicate that the ASST model can effectively capture complex flow phenomena over a wide range of Reynolds numbers. Quantitative comparisons show that the SST model generally underpredicts Reynolds stress levels, whereas the ASST model effectively alleviates this limitation through nonlinear corrections, resulting in improved predictive accuracy.

Conclusion This study provides an important methodological reference for improving the accuracy of hydrodynamic predictions for underwater vehicles.