RUMCars Forum

General Category => Off Topic Lounge => Topic started by: Barry on January 13, 2013, 09:42:35 AM

Title: Ground Effect
Post by: Barry on January 13, 2013, 09:42:35 AM

Saw this on Facebook and it reminded me of a great TV program many years ago on this beast.  Fantastic.

Thought I would add another photo - not ground effect!
Title: Re: Ground Effect
Post by: Big Al on January 14, 2013, 09:14:24 AM
Laminar flow (friend of Bandy Sandy), as used under Citroen CX. The Caspian Sea Monster, now known as an Ekranoplan. Fantastic apparent cul de sac of technology. Great images and film of these things and if you look further there are smaller privately made ones. Really good one in America. It is likely a well designed personal version will win the prize for flying however far it is of what ever pier it is on the south coast where people normal fall in dressed as superheros.

No idea what the massed blades of the jet engines are doing in the other picture though. Sure it is not someone mucking about.
Title: Re: Ground Effect
Post by: Barry on January 14, 2013, 12:04:00 PM
You will like this one.

Title: Re: Ground Effect
Post by: Big Al on January 14, 2013, 01:17:06 PM
The Blackburn Beverly flirted with having seating in the frontal area of the main wings for soldiers. The idea has not got adopted and I assume it is in part as wings tend to be of a higher aspect ratio/less drag than of earlier designs. This would reduce the space. In addition techniques for the hull are frame have improved meaning that space can be created in more convenient ways.

The Russian monsters were designed to shift men by the division into battle across the seas around their borders. The Americans opted for hovercraft with leeboards, effectively, for the same idea. All cold war initiatives to wrong foot the opposition. In the end the enemy seems to be religious indoctrinated nutters from various trees rather than regimes.
Title: Re: Ground Effect
Post by: Barry on January 20, 2013, 06:04:45 PM
New Photo
Title: Re: Ground Effect
Post by: marcus on January 20, 2013, 06:41:48 PM
Great stuff, there are various Ekranoplans operating on the Caspian Sea, up to some really big machines. A useful In-Between device in certain places.

Another weird and wonderful plane is the Junkers 38 which used to visit Croydon...6 passenger seats and windows in the leading edge of the wing.
Title: Re: Ground Effect
Post by: AndrewG on January 20, 2013, 07:31:43 PM
In the early 1990s I did a job in the former Soviet Union that used as a sub-contractor the design bureau where a lot of Ekranoplan testing was done.  They had a spectacular combined wind tunnel/water channel in which Ekranoplans could be tested at take-off (was it Saunders Roe who once had something similar for flying boats?).  The bureau was convinced that I could just drop a word in the right ear and they would sell hundreds in the West.....

I think the killer blow to Ekranoplans is trying to use them - they are not the sort of thing that can share sea space with conventional ships as avoiding collisions gets really quite tricky, particularly in rough seas.  The Russians just assumed that one would apply to the UN and have 'flight lanes' across oceans declared ship-free.  Which I think is what they did in the Caspian Sea and of course is what military aviation does the world over.

It was with great disappointment that I had to turn down a 'test flight' in a small one - sadly I was there to do a job, not have fun.
Title: Re: Ground Effect
Post by: Big Al on January 21, 2013, 08:41:48 AM
Just as large hovercraft the leakage from under the airdam is upset by rough water and there are conditions where operation is either ridiculously expensive in fuel or dangerous. Secondly neither craft has the ability to hope over shipping nor the agility to avoid it. The Ekranoplan could live in another form though. It has been mooted that in situations of permanent flow the principles could be used to create a 'flying' built up area that will remain above water and provide a dry environment using no land.
Title: Re: Ground Effect
Post by: marcus on January 21, 2013, 10:32:04 AM
My US business partner was an airliner captain and assured me that the Ground Effect for large airliners actually extends to about two hundred feet up, so Ekranoplans can build up high speed in level service, and use that speed to get over ships. However, weather is a problem and there are not many places where weather, other traffic, and payloads are ideal for Ekranoplan ops. I think Saunders Roe did have a big tank, and it was they who made the big SRN4 cross-Channel Hovercraft. I would love a flight in a really big flying boat.
Title: Re: Ground Effect
Post by: AndrewG on January 21, 2013, 04:11:35 PM
Yes, I understand that an Ekranoplan can, just, fly so can raise itself up enough to clear shipping - at the expense of significantly greater fuel consumption.

But like all these problems, it's the little details that catch you out.  You need to know in advance that a ship is there if you are going to gain altitude before you hit it but, even with modern radar, in a big North Atlantic swell, it is very hard to guarantee that you will see absolutely 100% of ships in advance.  And those poor buggers who want to sail their yachts across the Atlantic will just have to take their masts down.

But then something like the North Atlantic is just the wrong sort of sea for an Ekranplan.  They had no problem flying over a short chop, but quarter-mile-long Atlantic waves (or worse-still two-mile long Mozambique Channel waves) are a real problem as then you have to fly above them with all the fuel consumption that that demands.

I believe Lufthansa used to fly some of their Atlantic routes in ground effect over the Sargasso in the 1930s - even a conventional airliner works as a ground effect vehicle.  The arrival of jets, with lower drag at higher altitude, put paid to that.

One more thing that kills these craft is the same as for hovercraft - once they leave the water, regulatory bodies think they are aircraft and they get lumbered with all the associate costs and procedures, which then kills their economics.
Title: Re: Ground Effect
Post by: marcus on January 21, 2013, 04:26:37 PM
The infamous Dornier DO X flying boat could rarely get more than 1,000 feet up even when not fully loaded, and when it made its two flights across the Atlantic it was in GE a lot of the time!