Numerical analysis of turbulent fluctuations around an axisymmetric body of revolution based on wall-modeled large eddy simulations

Abstract

Wall-modeled large eddy simulation (WMLES) is used to investigate turbulent fluctuations around an axisymmetric body of revolution. This study focuses on evaluating the ability of WMLES to predict the fluctuating flow over the axisymmetric hull and analyzing the evolution of turbulent fluctuations around the body. The geometry is the DARPA SUBOFF bare model and the Reynolds number is 1.2×10⁷, based on the free-stream velocity and the length of the body. Near-wall flow structures and complex turbulent fluctuation fields are successfully captured. Time-averaged flow quantities, such as time-averaged pressure and skin-friction coefficients, and time-averaged velocity profiles on the stern, achieved great agreements between WMLES results and experimental data. Self-similarity of time-averaged velocity defects within a self-similar coordinate up to twelve diameters from the tail. A comprehensive analysis of second-order statistics in the mid-body, stern, and wake regions is condutced. Numerical results agree well with experimental data and previous wall-resolved large eddy simulation (WRLES) results about root mean square (rms) of radial and axial fluctuating velocities at the stern. Turbulent fluctuations including turbulent kinetic energy (TKE) and second-order velocity statistics are identified as dual peak behavior and non-self-similar over the wake length, consistent with previous findings in the literature. This assessment enhances the understanding of WMLES capabilities in capturing complex fluctuating flow around axisymmetric geometries.