Analyzing Wind Direction Flow Control on Full-Scale Amphibious Assault Ship Airwakes Using a Computational Fluid Dynamics Simulation

Lu, Y.; Shao, W.; Chang, X.; Chuang, Z., and Zhou, Z., 2022. Analyzing wind direction flow control on full-scale amphibious assault ship airwakes using a computational fluid dynamics simulation. Journal of Coastal Research, 38(6), 1181–1194. Coconut Creek (Florida), ISSN 0749-0208. This paper presents an aerodynamic study on flow control by different wind directions on full-scale amphibious assault ship (AAS) airwakes using computational fluid dynamics (CFD). The Reynolds-averaged Navier-Stokes (RANS) equation was employed to conduct a numerical simulation for the analysis of aerodynamic characteristics of the ship airwake flowfields under wind impacting. The aerodynamic performance of a small-scale landing helicopter assault (LHA) model was first simulated and then validated with Particle Image Velocimetry experimental data from the VSHAIP project of the NASA Ames Research Center. Employing CFD simulations, the computed unsteady ship airwakes compared well to experimental data. After validation, full-scale AAS airwakes were further simulated by CFD to capture the vortex patterns and velocity distributions of winds in the Head, Red, and Green directions surrounding the AAS. Building on this, the range of wind direction angles of relatively stable vertical wind speed above each landing point is discussed. The aerodynamic analysis and numerical method described in this study will build a strong foundation supporting the numerical simulation of the ship airwakes in full scale as well as small scale.