AI News, BOOK REVIEW: Vibrating Bat Wings Inspire Efficient Sea-Skimming Drones

Vibrating Bat Wings Inspire Efficient Sea-Skimming Drones

In addition, membrane vibrations are known to enhance leading edge vortex shedding, forming large roll up vortices of low pressure content which can significantly contribute to the total lift enhancement at high incidences.” If I were to attempt to translate all that, I would guess that the rapid wing wiggles (technical term there) helps air stick to the wing when it would otherwise break away.

In the late 1980s, the Sovietsdeployed a thing called an ekranoplan, which was a rather bizarre looking flying boat that depended on ground effect-generated lift to fly at up to 550 kilometers per hourover water: Technically, an ekranoplan is a boat, not an aircraft, because it’s restricted to water.

Boeing also toyed with a similar idea, called the Pelican: While able to fly at altitudes up to 20,000 feet, the Pelican would have functioned best as a trans-oceanic ground effect aircraft, with a payload of 1,400 tons and a range of 10,000 nautical miles at an altitude of about 20 feet.

TheAlekseyev Central Hydrofoil Design Bureau in Russia is planning on selling a bunch of these fancy newA-050 ekranoplans to the Chinese army: These will be able to carry up to 100 passengers at 450 kilometers per hour, with a range of 5,000 kilometers, looking totally cool and futuristic while doing it.

Ground effect (aerodynamics)

In fixed-wing aircraft, ground effect is the increased lift (force) and decreased aerodynamic drag that an aircraft's wings generate when they are close to a fixed surface.[1] When landing, ground effect can give the pilot the feeling that the aircraft is 'floating'.

The pilot can then fly just above the runway while the aircraft accelerates in ground effect until a safe climb speed is reached.[2] When an aircraft flies at a ground level approximately at or below the length of the aircraft's wingspan or helicopter's rotor diameter, there occurs, depending on airfoil and aircraft design, an often noticeable ground effect.

Ground effect also alters thrust versus velocity, where reduced induced drag requires less thrust in order to maintain the same velocity.[6] Low winged aircraft are more affected by ground effect than high wing aircraft.[7] Due to the change in up-wash, down-wash, and wingtip vortices there may be errors in the airspeed system while in ground effect due to changes in the local pressure at the static source.[6] Another important issue regarding ground effect is that the makeup of the surface directly affects the intensity;

Fluid-structure interactions of membrane wings in free-flight and in ground-effect

Currently, there is a growing demand to improve the aerodynamic performance of Micro-Air-Vehicles for extended mission time, higher payload capacity and improved agility.

Their wings have to operate within a challenging Reynolds number regime of Re =10(4)-10(5) which is known for its low energy content in the boundary layer, causing early flow separation and loss in lift production.

Multiple high-speed recordings involve lift, drag and pitch moment measurements with a load-cell, membrane deformation measurements with photogrammetry and digital image correlation (DIC)and flow measurements with planar/stereo particle image velocimetry (PIV).

Higher aspect-ratios are found to exploit the benefits of wing flexibility to a larger extend, showing a gain in peak-lift of up to 60% for an aspect-ratio of 2 and 31% for an aspect-ratio of 1 (in reference to rigid at-plates).

Review ArticleFlapping wing micro-aerial-vehicle: Kinematics, membranes, and flapping mechanisms of ornithopter and insect flight

The application of biomimetics in the development of unmanned-aerial-vehicles (UAV) has advanced to an exceptionally small scale of nano-aerial-vehicles (NAV), which has surpassed its immediate predecessor of micro-aerial-vehicles (MAV), leaving a vast range of development possibilities that MAVs have to offer.

Because of the prompt advancement into the NAV research development, the true potential and challenges presented by MAV development were never solved, understood, and truly uncovered, especially under the influence of transition and low Reynolds number flow characteristics.

Membrane wings in Ground effect: Experiment in wind tunnel November 2014, By Robert Bleischwitz

Membrane wing in ground effect. Modification in angle of attack and height over ground are investigated using DIC+ dynamic load measurement technique. University of Southampton.

Wing In Ground UAV with membrane wings

Test vehicle for the application of flexible membrane wings of UAV/MAVs, flying close to the ground. Feel free to contact me: modellwerft@freenet.de.

Membrane wings in Ground effect: Experiment in wind tunnel

Membrane wing in ground effect. Modification in angle of attack and height over ground are investigated using DIC+ dynamic load measurement technique. University of Southampton.

WIG - Wing in Ground Effect

A Wing In Ground-effect vehicle (WIG), is a vehicle that cruises little more than a few feet over flat surfaces, most often water. It can be seen as a transition between a hovercraft and an...

Seminar: Aerodynamics of membrane wings: By Robert Bleischwitz

Seminar: April 2015, University of Southampton TOPIC: Aerodynamics of membrane wings with focus on aspect ratio and ground effect.

This Ship Is A Hovercraft Until It's An Airplane - BTF

Behold The Future...This Ship Is A Hovercraft Until It's An Airplane. How low can you soar? When is an airplane actually a boat? That's as much a legal question as it is a philosophical...

Model Ground Effect Vehicle with Close Coupled Canards and short tail

1/6 Scale model "Hoverwing" type model ground effect vehicle to test different wing plans before full scale build - More info at This..

RC Bat Type Membrane Wing Glider 1st trial

RC コウモリタイプの膜翼グライダーを作ってみました。 試作1号機の滑空テスト状況です。 RC Bat Type Membrane Wing Glider 1st gliding test which is still under...

Slow motion wind tunnel membrane wing test

Memebrane wings tested in wind tunnel.

RC Bat Type Membrane Wing Glider 2nd Test

RC bat type membrane wing glider 2nd test on 14th Oct 2016 which was modified control mechanism and front side of the wing to have "Camber" from 1st test condition. Her maneuverability is well...