Numerical investigation of two-dimensional axisymmetric and three-dimensional flow simulations over a benchmark underwater vehicle.

This article focuses on the application and validation of two-dimensional (2D) axisymmetric computational fluid dynamics (CFD) simulations to predict turbulent flow around the bare hull of the Defense Advanced Research Project Agency submarine model (DARPA SUBOFF). The study demonstrates that 2D axisymmetric simulations, using the Reynolds-averaged Navier–Stokes (RANS) equations with the k–ω shear stress transport turbulence model, produce results for total drag, pressure distribution, wall shear stress, and velocity profiles that closely agree with three-dimensional (3D) simulations and experimental data from the David Taylor Research Center (DTRC). Verification and validation are conducted at three levels, including mesh sensitivity analysis via Richardson extrapolation, showing minor errors and significant reductions in computational time and resources compared to 3D simulations. The research highlights the efficiency and reliability of 2D axisymmetric CFD for preliminary hydrodynamic design and optimization of axisymmetric underwater vehicles, while noting its limitation to axisymmetric flow conditions without crossflow or angle of attack effects.