Naval Systems

 

Incompressible simlation of the unsteady airwake of a LHA ship.

 

JSF lift fan and jet plume interaction with LHA airwake.

 

Unsteady simulation of an AV-8B harriaer at a hover alititude of 30 ft.

Varied naval specific problems have been addressed by CRAFT Tech such as missile launcher interactions and aircraft/VSTOL landing problems on aircraft carriers. V/STOL aircraft such as the AV-8B Harrier and the F-35 Joint Strike Fighter (JSF) encounter unique challenges in performing takeoff and landing maneuvers during carrier operations due to the interaction of the jet downwash with the unsteady airwake generated by the ship superstructure and deck. Computational modeling and simulation are playing an important role in the study of these complex interactions and their impact on the design of aircraft flight control systems and operational envelopes. The CRUNCH-CFD code is being used in the development and validation of a physics-based, high fidelity CFD model for predicting the coupled airwake of a ship-V/STOL-aircraft combination. The challenges include geometric complexity, the magnitude of the simulation domain, and the broad array of physical phenomena that range from the low velocity, low frequency, large-scale vortex shedding from the ship superstructure to the high-speed, high frequency acoustic emissions that characterize the V/STOL aircraft.