What’s that in the sky? It’s not a bird, or a plane, it’s … a flying submarine?!
Meet the Flimmer.
That’s short for “flying swimmer,” and comes from the “what will the Naval Research Laboratory dream up next?” category.
It’s hard to argue with the logic behind what some have dubbed the “duck drone.” Covering vast distances is far easier in the air than underwater. In addition, an air-delivered unmanned underwater vehicles can operate in areas that lack easy access.
Yet the challenges are many, as aerodynamics and hydrodynamics require far different designs. For example, weight is bad for a thin-skinned aircraft, but good for a thick-skinned submersible. According to officials who commented in NRL’s magazine Spectra, “[c]ombining these two diametrically opposed vehicles to design a flying submarine comes down to a balancing act between buoyancy, weight, and structural elements.”
Still, it appears that the sky is the limit for unmanned submarines (sorry, we couldn’t resist). The Flimmer program is off to a good start, as a test sub that merged basic submarine and aircraft designs was recently dropped from 1,000 feet and hit speeds of 50 knots as it was manually guided to a target in the water. Once submerged, two inflatable bladders provided pitch and heave control as the vessel hit speeds of 10 knots. Officials found that “controlling the vehicle in forward motion underwater was identical to ‘flying’ the aircraft. The configuration of an aircraft shape and traditional aircraft control surfaces of rudder, elevator, and ailerons functions exactly the same whether in air or water.”
The technology has since been applied to the Wrasse-inspired Agile Near-shore Deformable-fin Automaton, or WANDA — a fish-like underwater vehicle. The final fish out of water is expected to have a wing and four fins that will provide maneuverability and stability underwater. Designers must figure out how to make fins that can survive the forces of splashdown. A hollow, flood-able wing is also under construction.