applications for wing in ground effect vessels,a transformational concept

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Applications for Wing in Ground Effect Vessels, a Transformational Concept John S. Canning NSWC DD Code D11 (540) 653-2832 [email protected] .mil

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The Lun-class ekranoplan was a Ground Effect aircraft designed by Rostislav Evgenievich Alexeyev and used by the Soviet and Russian navies from 1987 to sometime in the late 1990s.When an aircraft is flying at an altitude that is approximately at or below the same distance as the aircraft's wingspan or helicopter's rotor diameter, there is, depending on airfoil and aircraft design, an often noticeable ground effect. This is caused primarily by the ground interrupting the wingtip vortices and downwash behind the wing. When a wing is flown very close to the ground, wingtip vortices are unable to form effectively due to the obstruction of the ground. The result is lower induced drag, which increases the speed and lift of the aircraftA Wing-in-Ground effect craft (WIG) is a vessel with wings that cruises just above the water surface, it is floating on a cushion of relatively high-pressure air between its wing and the water surface. Is also known as a WIGE (Wing-in-Ground Effect), or a Wing ship.It is the ultimate low-drag marine craft.It is a very high-speed, sea-based platform.

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  • Applications forWing in Ground Effect Vessels,a Transformational ConceptJohn S. CanningNSWC DD Code D11(540) [email protected]

  • What is a WIG?A Wing-in-Ground effect craft (WIG) is a vessel with wings that cruises just above the water surface, it is floating on a cushion of relatively high-pressure air between its wing and the water surface. Is also known as a WIGE (Wing-in-Ground Effect), or a Wingship.It is the ultimate low-drag marine craft.It is a very high-speed, sea-based platform.Some WIG vehicles have the ability to fly without ground effect as well, but inefficiently as compared to aircraft.Airfisch 8 by Airfoil Development GmbH

  • Caspian Sea MonsterThis is the largest WIG produced to-dateLength: 348 ft, Wing-span: 131 ft

  • What a WIG is not.Although it is capable of flying, it is not an aircraft.WIGs are not designed or built to be aircraft.The Caspian Sea Monsters, for example, were built in shipyards, using ship construction techniques.However, they could benefit from modern aircraft design and construction technologies, such as integrated product models and composite materials.They are also not hydrofoils, hovercraft, or surface effect ships.Some versions have been designed that will hover.These distinctions are blurring, however

  • Two Perceived Fundamental Uses:Weapons PlatformTraditional warship roleIncludes being a Mothership for unmanned vehiclesLogistics PlatformFalls between being a ship and an aircraft for delivering cargo for both speed and cost.Tendency exists to view this as an either/or choice.Suggest that appropriate design might lead to a RO/RO family of capabilities that could provide both uses.

  • A Weapons Platform View

  • A Transformational Question:Is the military object to clear the minefield, or to quickly get to the other side of the minefield, and do something to the enemy?A WIG will travel over the top of a minefield at very high speed, without damage, and perform its mission on the other side.Clear the minefield?Hop over the minefield?

  • A Corollary:Q: If we can jump over minefields, how about enemy submarine patrol areas?A: You bet!!!

  • OK, So What if You Really Want to Clear a Path Through a Minefield?Have a WIG drop and control a number of UUVs designed to hunt/kill mines on its way over the minefield, and have them clear the path in a parallel effort, as opposed to starting at one edge of the minefield and working through it in a serial manner.MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELDMINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD MINEFIELD

  • ASCMs:An Example for Large Ship ASUWUtka: Armed with six SS-N-22 SUNBURN missiles. Length 242 ft.NOTE: Due to ship construction techniques used, ONI has concluded that Utka would be difficult to destroy.

  • Sea Sniper:An Example for ASWBased on RAMICS technology could put this on a WIGMoving Target/Moving Shooter

  • FYI: Rapid Airborne Mine Clearance System (RAMICS)Uses a 30mm Bushmaster II chain gun for shallow water minesStationary Target/Stationary Shooterhttp://www.onr.navy.mil/sci_tech/ocean/Info/RAMICS/ramics.htm

  • Small Boat ASUWLethal30 mm chain gunSame one for Sea SniperLook down/Shoot downStay out of lethal range of small boat weaponsOther guns and/or missile systemsNon-lethalActive Denial TechnologyHPM system causing intense skin pain for exposed personnelRunning Gear Entangling SystemSpecially designed boat-stopping rope

  • Active Denial TechnologyThe Air Force is investigating an airborne version of this current ACTD. Whatever they develop could be adapted to WIGs.http://www.de.afrl.af.mil/factsheets/activedenial.html

  • Other ExamplesAC-130 Gunship w/ 105mm gunAirborne LaserWhile not WIGs, these examples indicate that other, large weapon systems have, and are, being integrated into airborne platforms. This could be done for WIGs.

  • A Logistics Platform View

  • A ComparisonSpeed - 40 + knotsRange 4000+ nm @ 40ktsDraft 10 7Length Overall - 370 ft Beam - 100 feetWeight - ? Cargo capacity - 1100 tons Operate at speed in 15 ft seasSpeed 270 knotsRange 930 nmDraft Draft? What draft?Length 348 ftWing span 131 ftWeight 540 tonsCargo capacity ?Operate at speed in any seasDirect comparisons are difficult due to differences on how lift capability is figuredAustralian HSVRussian KM

  • WIG LogisticsDo you want it there fast or do you want it there cheap? This has always been a concern of manufacturers, merchants and logisticians. When the shipment is trans-oceanic, mile for mile, sea travel is the cheapest. Air shipment is faster, but costs five times more per kilogram of weight. However, WIG technology can deliver large amounts of cargo with significantly less fuel consumption (50% more payload with 35% less fuel consumption than similar-sized aircraft 75% less fuel than comparable-sized hydrofoil ferries).Quote from: http://www.geocities.com/equipmentshop/wig.htmRussian CHDB Chaika-2

  • Comparison of Relative $/lb and Speed to Move CargoShipAircraftWIG

    Chart1

    1

    5

    2.3

    Speed, kts

    Relative $/lb of Payload

    Sheet1

    VehicleSpeed$/lb

    Ship151

    Aircraft5655

    WIG5002.3

    Sheet2

    Sheet3

  • Implications for Strategic Mobility CapabilityPrior to the Gulf War, four separate DoD studies concluded we didnt have enough sealift to meet mobility demandsOlds, Bradley L. The Impact of Wingships on Strategic Lift, Thesis for the Naval Post Graduate School, Monterey, CA, SEP 1993DoDs Mobility Requirements Study & Bottom-Up Review Update (1995) indicate that the U.S. still had an overall strategic mobility shortfallLosi, Peter C. The Wingships Potential For Strategic Lift, Executive Research Project for The Industrial College of the Armed Forces, National Defense University, Washington, D.C., 1995Does that mean we need WIGs for strategic mobility?Depends on if a shortfall still exists when WIGs are fieldedWe are undergoing the RMAForces getting smallerLogistics decreasing

  • Strategic Airlift In Support of Military CONOPSPelican Container Cargo Aircraft Boeing Phantom Works, Air Vehicle Advanced Design Long Beach, California This is a current LAND-BASED proposal

  • Why are WIGs not more Common?The main problem is getting out of the water, since the required power for take-off is a number of times higher than that required for cruising. This is due to the high drag in the water just before leaving the water surface, also called "hump drag.Ever since the very first experimental WIG craft were built in the 1930s, longitudinal stability has been recognized as a very critical design factor. When not designed properly WIG craft show a potentially dangerous pitch up tendency when leaving (strong) ground effect.A WIG craft that fulfills all efficiency expectations would be extremely big, hundreds, maybe thousands of tons. Only at this size the relative height will be sufficiently small to be more efficient than for example a 747 on a trans-Atlantic route and still be clear of the waves.Investors for a project to develop a craft this size will not be easy to find if the technology has not proven itself first.

    The Russians solved all but the last problem

  • Getting a WIG Out of the WaterTo address the hump drag issue, Beriev produced this WIG that incorporates a hydrofoil.

  • Addressing the Longitudinal Stability IssueFlying wings, such as the YB-49, were inherently unstable. This issue was solved for the B-2 by the use of computer control. The same could be done for WIGs.

  • A Design ChallengeDesigning a WIG craft is much more challenging than designing a ship or an aircraft. Especially in the preliminary design phase, many problems have to be addressed at the same time. One cannot isolate wing, tail and fuselage design, which is common practice to a certain extent in aircraft design. Rules of thumb are hardly available and simple analytic calculation methods for performance and stability of a WIG craft do not exist.Meeting this challenge would provide the Navy a very valuable transformational capability

  • Ideal WIG MissionsQuick response precision strike platformSpecial operations force insertionMine clearing & layingDeep sea submergence recoveryUrgent re-supply of ships afloatDisaster responseSource: ARPA Mission Analysis Team for 1994 wingship study

  • Projections on WIG TechnologyRussian analysts consider that WIG technology is now at the point where the U.S. can build an ocean-skimming WIG Air-Mech craft. It would weigh 5,000 tons and carry a cargo of 1,500 tons for a distance of 20,000 kilometers (12,420 miles) at a speed of 400 kilometers per hour (250 miles per hour). Such a craft could deliver 1,200 tons of military equipment and cargo plus 2,000 Soldiers. Russian analysts feel that, with financial backing, they could build a 5000-ton craft capable of lifting 1200 tons or 3000 passengers now. It could fly at 800 kilometers per hour (500 miles per hour) with a range of 16,000 kilometers (9936 miles).Quote from: http://www.geocities.com/equipmentshop/wig.htmArtists conception of a proposal to ARPA by Aerocon, 1993 566 ft in length

  • CostsEstimates by Aerocon in 1994 put full-scale development and production costs in the range of $6.5 - $8.5B, but would save billions no longer necessary for other types of force projection, overseas deployment operations, pre-positioning, and support costsProgram costs of 13 WIGs estimated to total $15.2B, using Aerocon figuresEstimates by ARPA were as much as $50 - $60B just for development, but admitted that costs were hard to nail downAir Force estimated $95B, but wasnt really interested since it was sea-basedR&D cost estimates, which vary considerably, are largely unreliable because neither aircraft nor ship parametrics apply.Recent Boeing figures are more than Aerocons estimates, but much less than ARPAs. Boeing is looking at significant cost-sharing from commercial transportation industry. DoDs share would be negotiable.

  • ScheduleReported estimates from beginning of development to IOC ranged from 10 years to over 13.5 years (the median figure for IOC from an acquisition Milestone I decision).

  • RisksVuja DeWe aint never been here beforeFinding a U.S. builder willing to take this onAt least one appears to be ready to address WIG technologyPropulsionLarge engine technologyDiffering power requirements for takeoff/cruiseSaltwater environmentRough water performanceCan it stay in ground effect?Does it need to stay in ground effect?Russian experience indicates that you can pull up to go over rough water/obstaclesProgram sponsorshipNo natural sponsorFalls in the cracks between the Air Force and the NavyFalls in the cracks between NAVSEA and NAVAIRMaterialsLightweight, corrosion resistant

  • Nuclear Propulsion for AircraftNB-36HBetween 1946 and 1961, the Air Force and the Atomic Energy Commission spent more than $7 billion trying to develop a nuclear-powered aircraft. Although no airplane ever flew under nuclear power, the Air Force converted this B-36 bomber, known as the Nuclear Test Aircraft, to carry an operating three-megawatt air-cooled reactor to assess operational problems (it made 47 flights over Texas and New Mexico between July 1955 and March 1957).

    The technicians and scientists did their best to succeed with the ANP program, and they did make a great deal of technological progress. However, without guidance their efforts were too spread out. The blame for the failure of the ANP program cannot rest with the technology, it belongs to the politicians and the military. While technical objectives were generally met by the contractors, there were apparently no firm military requirements set by the Joint Chiefs of Staff.

  • Thoughts on the Risk of Nuclear Propulsion History often characterizes past civilizations by the magnitude of the energies they harness wood fires, coal fires, coke fires, and combustion of oil. Currently, we have reached the end of the chemical energy ladder with the combustion of hydrogen. Very likely, we will be judged by future historians by our ability to accept the challenge and demands presented by the use of nuclear power.The fears invoked by the perceived risk are unreasonable. the risk of all the nuclear power plants in the US causing ten deaths in a one-year interval is 100,000 times less than having ten people killed in an airplane crash. Its even 1000 times less than the chance of ten people dying from dam failures. Letting fear of a technology rule the course of history for a civilization is irrational. We can easily imagine early man finding a flaming branch after a lightning storm. Upon returning to his lair to show the new light to his tribe, he accidentally burns his fingers, drops the branch and sets fire to skins, bedding and surrounding detritus. The conclusions by the tribe: the flame is bad, evil; put it away; hide in the dark. But those who choose to conquer their fears will progress. Those who run and hide in the dark will not.Are We Afraid of a Little Fire? by Dr. Stephen D. Howe, Science Fact article in the JUL/AUG 2002 issue of Analog magazine, pg 60-61

  • Why a WIG Needs to be LargeDr. V.V. Sokolov, Chief Designer at CHDB, told DARPA investigators in a 16 AUG 93 interview that the height of the wing above the level water line is usually:h = H/2 + 0.1cwhere:h = height of wing above level water lineH = average of 3% highest wavesc = wing chordIt is easy to see from this that for zero height, h, there is a relation between wave height and the minimum wing chord (the distance from leading edge to trailing edge) required to stay above the waters surface in a wave environment. This relation is plotted here. Wing size quickly becomes large for increasing sea state.

    Chart1

    1.640415

    8.202075

    20.50519

    41.010375

    65.6166

    98.4249

    147.63735

    229.6581

    Min Wing Chord

    Sea State

    Wing Chord, ft.

    Minimum Wing Chord vs Sea State

    Sheet1

    Sea StateMin Wing ChordWave Height

    11.6404150.328083

    28.2020751.640415

    320.505194.101038

    441.0103758.202075

    565.616613.12332

    698.424919.68498

    7147.6373529.52747

    8229.658145.93162

    Sheet2

    Sheet3

  • Annual Sea State Occurrences in the Northern HemisphereSource: ARPA Wingship Investigation, 1994, Vol 1, Fig 5.4.4.1-1

    Chart1

    0.799.31.398.7199

    6.892.56.492.36.692.4

    23.768.815.576.819.672.8

    27.84131.645.229.743.1

    20.6420.3620.9424.2620.7922.31

    13.157.2115.039.2314.098.22

    6.051.1672.236.821.4

    1.110.051.560.671.340.06

    0.05-00.67-00.060

    North Atlantic

    North Atlantic (cumulative)

    North Pacific

    North Pacific (cumulative)

    Northern Hemisphere

    Northern Hemisphere (cumulative)

    Sea State

    Probability

    Probability of Sea State in the Northern Hemisphere

    Sheet1

    Sea StateNorth AtlanticNorth Atlantic (cumulative)North PacificNorth Pacific (cumulative)Northern HemisphereNorthern Hemisphere (cumulative)

    0-10.799.31.398.7199

    26.892.56.492.36.692.4

    323.768.815.576.819.672.8

    427.84131.645.229.743.1

    520.6420.3620.9424.2620.7922.31

    613.157.2115.039.2314.098.22

    76.051.1672.236.821.4

    81.110.051.560.671.340.06

    >80.05-00.67-00.060

    Sheet2

    Sheet3

    Chart1

    00.328083

    0.3280831.640415

    1.6404154.101038

    4.1010388.202075

    8.20207513.12332

    13.1233219.68498

    19.6849829.52747

    29.5274745.93162

    45.93162>8

    Min

    Max

    Sea State

    Significant Wave Height, ft

    Wave Heights vs. Sea State

    Sheet1

    Sea StateMinMax

    0-100.328083

    20.3280831.640415

    31.6404154.101038

    44.1010388.202075

    58.20207513.12332

    613.1233219.68498

    719.6849829.52747

    829.5274745.93162

    >845.93162

    Sheet2

    Sheet3

  • Significant Wave Height, ftTen-Day Period, JAN 2001

  • Significant Wave Height, ftTen-Day Period, JUL 2001

  • Shared DevelopmentThe Russians have more experience working with this technology than any other group.Teamed with Aerocon for ARPA effortCurrent efforts with othersLikely worthwhile developing a teaming relationship with them in order to take advantage of this expertise

  • Admiral Cebrowskis Transformational Capability Checklist:Does it enable a new concept of operation?Does the new system or idea enable a difference in kind, not degree?Is it robust in the face of a wide range of threats?Does it broaden the competition more than legacy approaches?

    YesYes

    YesYesQuestion:WIGs:

  • Conclusions & RecommendationsWIGs are not new, but the technology hasnt been fully explored.It offers significant advantages to the Navy that can master it.It is truly transformational.Recommend we pursue WIG technologyRussian Orlyonok A90.125 Length 190 ft

    *