Ekranoplan Technology

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What is Wing-in-Ground Effect? – What is an Ekranoplan?

Wing-in-ground effect (WIG) sounds complicated but is really very simple; it is the interaction of airflow between a surface and something flying close to it, because when a wing flies close to a surface the airflow gets squashed, as demonstrated by the sea-skimming albatross in the picture below. This causes an increase in the lift generated and a decrease in the drag - so it becomes very much more efficient.

An Ekranoplan or WIG vehicle is simply a craft that rides on this effect; It's weight can be muchgreater yet it's power requirement is much less than if it were trying to fly in free air. If already this is sounding a bit complicated, then let us imagine it is just the same thing as skimming a playing card across a table - it tends to glide on forever. Or riding on the back of a pelican (one of the heaviest flying birds), that has learned to glide effortlessly over the surface of the sea using this 'ground-effect'.

We also may be familiar with 'ground effect' from road vehicle technology; racing cars are designed to use negative ground effect to suck themselves to the road for greater traction.

But Why Do It?

Because ground effect enables us to travel over the surface (albeit just above the surface) at speeds around 100 knots, in a vehicle that is more simple than an aeroplane and can carry more payload than an aeroplane, for less fuel than an aeroplane, but without the surface contact, sea sickness wake and wash of a boat! So we have a new class of surface vehicle that is faster and more comfortable than a boat but much cheaper than an aircraft. And yes, it is a surface vehicle, even though it is flying – because it’s height from the surface is governed by the extra lift from ground effect, which it loses as soon as it tries to get any higher.

This technology transforms a seaway into a freeway, without the cost of building the road, and in places where roads may not be possible. with the benefits:

  • Very fast.

  • Smooth comfortable to travel on.

  • Very energy efficient.

  • Kind to the environment with no wake or wash to damage it or upset other water users.

  • Immune to sea currents.

  • Cheaper capital & operating cost than an equivalent aircraft.

Civil applications include inter-island passenger ferry, luxury resort taxi service luxury cruising craft, mobile medical facility.

In a military role such craft have the additional benefit of natural stealth, as they skim at high speed amongst wave clutter on radar and leaving no visible wake. This gives less than two minutes warning to a target. Military applications include anti-piracy, anti-drug-trafficking interception and enforcement, wide area EEZ patrol, insertion and covert operations.

In many patrol situations a the combination of UAV + WIG patrol/interceptor may offer greater effectiveness than conventional warship + helicopter, but for far less cost.

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The Brown Pelican has learned to glide effortlessly by riding in ground effect. Five pelicans demonstrate this by gliding in close formation just inches above the water surface as they capturing ground-effect vortices beneath their wings.
(Photo by Mia McPherson. Do not use this image without contacting the owner: www.onthewingphotography.com)



The Wright brothers flew their 'Flyer' in ground effect and so started the age of aviation.



The biggest ever ekranoplan - the Soviet KM - at 550 tonnes.



The Fischer Flugmechanik HoverWing 2VT 2-seat technology demonstrator during 3000km of sea trials.



The civil HoverWing 20 - 20 seat passenger craft.


As a military variant - the HW20MIL
Technology links:

HoverWing Brochure

HoverWing technology promotional video.

Soviet KM Caspian Sea Monster Video





The Future - coming to a port near you.