In the present work, the influence of a neutral atmospheric boundary layer (ABL) on a ship airwake is evaluated in the context of helicopter operations in complex environments. A ship geometry representing the Simple Frigate Shape 2 is immersed into a large eddy simulation–resolving, unsteady ABL. The ship is modeled using the immersed boundary method to simulate complex geometry in the context of a Cartesian mesh. Several baseline, uniform-inflow cases establish the agreement with both previous computational fluid dynamics results and experimental data. Comparison of the baseline uniform-inflow cases to the ABL cases provides insight into the fundamental topology differences present in real airwakes. It is observed that ship airwakes are considerably different in the simulated unsteady ABL. Specifically, the ABL cases display an increased high-frequency energy content associated with small-scale turbulent fluctuations. These additional effects on the airwake can potentially affect the operation of helicopters in the highly unsteady airwake region and thus should be taken into consideration for more realistic dynamic interface modeling.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Aerospace Engineering
- Mechanics of Materials
- Mechanical Engineering