Wing in Groundeffect (WIG) - Technology
Sea birds often fly in closed proximity to the water surface - utilizing the Groundeffect for effective flying. The wing experiences an increase in lift and a decrease in drag, which is due to two mechanisms:
- An increase in static pressure under the aerofoil due to the finite distance with the ground (chord dominated ground effect), which increases lift
- The disruption in the formation of wing tip vortices due to the proximity of the ground (span dominated ground effect), which reduces induced drag.
Wing-In-Groundeffect - Advantages:
Wing-In-Groundeffect crafts (WIG) are an emerging technology that provide surface transportation over water, with characteristics in between air crafts and marine crafts, in terms of speed, cost, maintenance and payload capacity. With cruising speed of 180 km/h they are faster than almost all other sea crafts and, over short/medium distances, they provide journey times comparable to helicopters and air crafts. Flaring above the water, without water contact, WIG crafts provide an efficient means of transportation, with no sea motion fatigue and no wake, while offering natural stealth.
- Speed is much higher than all other sea crafts, between plane and ship
- Infrastructure requirements are simple, identical to those of boats
- Opens new opportunities for regular high speed boat travel
- Exceptionally friendly to the environment due to low use of energy and exchange of fluids with the sea, hardly producing any wake
- Super efficient due to energy-saving flare-mode, extremely low fuel consumption
- Travel comfort at premium quality due to smooth gliding chracteristics provided by an air cushion and therefore no sea sickness
- Can be operated with a sports boat license (but a good briefing and training is strongly recommended)
- WIG crafts are recognized universally as maritime vessels for construction, insurance, operator licensing and registration requirements.
During the cold war in the 1960s the research into WIG technology began, the Soviets developed the square planform wing shapes for huge Ekranoplans led by the Russian engineer Rostislav Alexeev (1916 - 1980). Several of these large war crafts have been build and operated by the Russian military end of the last century, but no commercial versions of Ekranoplan have ever been build. Almost at the same time Dr. Alexander Martin Lippisch (1894 - 1976) developed the Reverse Delta Wing providing more pitch stability in Groundeffect and also a better surface clearance height including kinetic jumps. SeaFalcons aerodynamic is based on the Reverse Delta Wing design.