Table Of ContentWIG Craft and Ekranoplan
· ·
Liang Yun Alan Bliault Johnny Doo
WIG Craft and Ekranoplan
Ground Effect Craft Technology
123
LiangYun AlanBliault
MarineDesignandResearchInstitute A/SNorskeShell
ofChina(MARIC) 4098Tananger
1688XizhangNanRoad Norway
200011Shanghai [email protected]
People’sRepublicofChina
[email protected]
JohnnyDoo
TeledyneContinentalMotors
2039BroadStreet
P.O.Box90
Mobile,AL36601
USA
[email protected]
ISBN978-1-4419-0041-8 e-ISBN978-1-4419-0042-5
DOI10.1007/978-1-4419-0042-5
SpringerNewYorkDordrechtHeidelbergLondon
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Preface
In the last half-century, high-speed water transportation has developed rapidly.
Novel high-performance marine vehicles, such as the air cushion vehicle (ACV),
surface effect ship (SES), high-speed monohull craft (MHC), catamaran (CAT),
hydrofoil craft (HYC), wave-piercing craft (WPC) and small water area twin
hull craft (SWATH) have all developed as concepts, achieving varying degrees of
commercialandmilitarysuccess.
PrototypeACVandSEShaveachievedspeedsof100knotsinflatcalmcondi-
tions;however,thenormalcruisingspeedforcommercialoperationshasremained
around35–50knots.Thisispartlyduetoincreaseddraginanaveragecoastalsea-
waywheresuchcraftoperateservicesandpartlyduetolimitationsofthepropulsion
systemsforsuchcraft.Waterjetsandwaterpropellersfacelimitationsduetocav-
itation at high speed, for example. SWATH are designed for reduced motions in a
seaway,butthehullformisnotalowdragformsuitableforhigh-speedoperation.
So that seems to lead to a problem – maintain water contact and either water
propulsionsystemsrunoutofpowerorcraftmotionsandspeedlossareaproblem
inhigherseastates.Theonlywaytohigherspeedwouldappeartobetodisconnect
completelyfromthewatersurface.
You,thereader,mightrespondwithaquestionaboutracinghydroplanes,which
manage speeds of above 200 kph. Yes, true, but the power-to-weight ratio is
extremelyhighonsuchracingmachinesandnoteconomiciftranslatedintoauseful
commercialvessel.
Disconnection of the craft from the water is indeed a logical step, but it has its
consequences.Thecraftmustbepropelledbyairanditwillhavetobesupportedby
airaswell.Alowflyingaircraft?Insomeways–yes–butwithadifference.When
anairplanefliesveryclosetothegroundamuchhigherpressurebuildsupunderthe
wings–groundeffect.Someearlyhovercraftwereconfiguredtocaptureairasthey
movedforward–capturedairbubblecraft.
Combine ground effect with a geometry specifically designed to enhance the
effectandyouhaveacraftthatmightbeabletoachievemuchhighercruisingspeed.
Flyingabovewaves,itsmotionsmightalsobemuchreduced.Thisideagavebirth
tothewing-in-groundeffect(WIG)craft.
The original type of WIG can be traced from at the beginning of last century.
Actually,in1903,theWrightBrothersflewtheirfirstairplaneoverrelativelylong
v
vi Preface
distances in the surface effect zone. Engineer Kaario of Finland started tests of
craft lifted by ground effect in the middle of 1930s. However, due to limitations
in the efficiency of structural materials and available engine power, the WIG was
notdevelopedfurtheruntilthebeginningofthe1960s.
ThesewereideasthatexcitedAlexeevinRussiainthe1960sand1970safterhis
institute had developed several series of hydrofoil designs. Alexeev and his team
of Russian pioneers in this new vehicle technology were interested in very high
speeds, and their programme was developed directly from hydrofoil research. The
craftwerechristened“Ekranoplan”.Paralleleffortsonprototypecraftandtheoret-
ical analysis gradually built experience and understanding through the 1970s and
1980sleadingtothefirstmilitaryservicecraftbasedintheCaspianSea.Thiswas
atrulyoutstandingtechnologicalachievementdeliveredthroughvisionarysupport
fromtheRussianNavy.
InGermany,alsointhe1970s,researchandprototypecraftaimedatusingground
effectwasalsocarriedout.RatherthanthelargemilitarybudgetavailableinRussia,
theGermanprogrammeswerefundedprivatelyandlaterwithlowlevelsupportfrom
government. This work led to ground effect craft suitable for high-speed coastal
patrol,thoughinlimitedseaconditions.
Atthebeginningof1970s,RussianengineersBartiniandR.Y.Alexeevinvented
power-assistedliftarrangementsforWIGcraftbymountingjetenginesinfrontof
the main wing to feed engine exhaust air into the air channel under the wing to
createtheso-calledpower-augmentedramwing-in-groundeffectcraft(PARWIG).
This augmented lift improved the take-off and landing performance by reducing
take-offspeedanddistance.
The full story of Alexeev’s craft is outlined in Chapter 2 together with other
developmentsfromaroundtheworld.Thetechnicalachievementswerehighlysig-
nificant,anditisapitythattheeconomicsituationinRussiathroughthe1990swas
such that the programme had to be stopped. It may be some time before we see
machinestoequaltheKMandSpasatel.
In recent years, researchers in China and Russia have mixed air cushion tech-
nologyintotheWIGtocreatethedynamicaircushioncraft(DACC)anddynamic
aircushionwing-in-groundeffectcraft(DACWIG)toproducecraftwithamphibi-
ouscapabilityandmuchhighertransportefficiencyatmediumcruisespeedsinthe
range150–250kph.
Since a WIG has several operational modes (floating hull, cushion and plan-
ing,andair-bornemodes),thecraftdesignisrathermorecomplex thanaircraftor
othermarinecraft.AWIGnormallyjusttransitsthroughallthemodesexceptflying
in ground effect, but unfortunately the drag forces and motions are the greatest at
speedsbelowtake-off,soeffectivedesignfortheconditionsmetduringthetake-off
and landing runs is essential to a successful WIG design. The challenges are not
overthough–quasi-staticanddynamicstabilityofaWIGwhenflyingisstrongly
influencedbyboththeflyingheightandthecraftpitchangle.
Research into these areas is at an early stage and much more knowledge in the
different areas is needed. In this book, we give an outline of the knowledge as it
Preface vii
exists right now. This provides a starting point, though readers are encouraged to
seekoutfurthersourcesforthemselves!
Some accidents have occurred on full-scale WIG craft, so that there is some
uncertaintyastothesafetyofWIGforpotentialoperatorsatpresent.Thisisbeing
addressed by a technical committee of the International Maritime Organisation
(IMO)whohavepublishedasafetycodeintheformofguidelinesforWIGin2003.
The technology is indeed still somewhat experimental and needs a build-up of
operational experience, even if it is at relatively small scale, in order to develop
confidence for the commercial industry to gain enthusiasm for this new form of
transportation. The IMO guidelines should help a lot in this respect, but practical
operations,perhapsfollowingtheexampleofthemanySR.N6hovercrafttrialsoper-
ationsandexpeditionjourneysinthe1960sand1970s,willbeneededtoprovetheir
capabilityandvaluetosociety.
On an international basis, the WIG craft is now recognised basically as a high-
speed marine vehicle and will be certified as such, rather than being certified by
aerospace authorities. This has significant cost and operational advantages that
shouldassistinthecraft’scommercialisation.
WIGarebaseduponacombinationofaircraftandmarinetechnologywhilebeing
differentfromeither.WIGoperatebothonwaterandinairaswellasontheedgeof
bothmedia.AWIGisneitheranairplanenorwatercraftassuch.Itisratherdiffer-
ent either from airplane industry (sophisticated lightweight structures, high power
intensity,automated,heavycertificationrequirements,expensiveconstructionetc.)
orfromwatercraft(experiencebaseddesign,relativelyheavystructure,robust,low
cost, etc.). The WIG borrows from both technologies to achieve a high speed and
lightweight,yetlow-costmarinevehicle.
Ourbookbeginswithageneralreviewofgroundeffecttechnologyandahistor-
ical review to give a background to the main body of the text covering the theory,
as well as a design approach for WIG. This is the first major text on this subject
outsideRussia,sowehopetoreachaworldwideaudienceandencourageinterestin
thistechnologyinbetweenthemarineandaerospaceworlds!
There are this Preface, 13 chapters and Backmatter in the book. We intro-
duceWIGcraftconcepts andbackground development inChapters1and2.From
Chapters 3,4,5,6,7,8and9,thebook describestrimandlongitudinal forcebal-
ance, static hovering performance, aerodynamic characteristics, stability, drag and
poweringperformance,seakeepingqualityandmanoeuvrability,andmodelexper-
imentalinvestigations.Thematerialsandstructures,powerplantselection,andlift
andpropulsionsystemselectionareintroducedinChapters10,11and12.Inthese
chapters,theissuesrelatedtoWIGdesignareconsideredasaderivationfromair-
craftormarinedesignratherthangivingadetailedtreatise.InChapter13,ageneral
approachtoWIGconceptspecificationanddesignisdescribed.
ThePostscriptdiscussesprospectsforthefutureandaseriesoftechnicalissues
concernedwiththedevelopmentofWIGthatfaceresearchersandengineersinthis
area at present. There is so much to work on at present. The WIG principle can
be applied to a wide envelope of operational speed and environmental conditions,
viii Preface
leadingtocraftasdifferentasglidersandjetairlinersintheaircraftworld.Inaddi-
tion,iflongdistancetransportationistobecomereality,WIGwillneedanewform
of“trafficlane”agreedatinternationallevelanddocumentedoncharts.Significant
opportunitiesawaitus!
A comprehensive listing of references is included at the end of the book, clas-
sified by chapter. These should be useful to the reader to provide more detailed
informationandsupportfortheanalysisanddesign.
The authors aim with this book to provide a useful reference for engineers,
technicians, teachers and university students (both undergraduate and postgradu-
ate),involvedinthemarineengineeringworldwhoareinterestedinWIGresearch,
design,constructionandoperation.
SincetheWIGisanoveltechnologyandstillinitsinitialdevelopment,thepre-
sentationofsomeofthetheoryshouldbeconsideredasstatementofcurrentstateof
(limited)art,soreadersshouldtakecaretocheckforthemselvesthevalidityofthe
theoriespresentedhere.Theauthorswillbepleasedtohavecommentsandfeedback
fromreaders.
Shanghai,PRChina L.Yun
Tananger,Norway A.Bliault
Mobile,Alabama J.Doo
May2009
Acknowledgements
The authors would like to express their sincere thanks to the leadership and col-
leaguesoftheMarineDesignandResearchInstituteofChina(MARIC)andHPMV
Design Subcommittee of CSNAME, including Prof. Xing Wen Hua, Prof. Liang
QiKang (Managing Director,MARIC),Mr.Wang GaoZhong (Deputy Managing
Director of MARIC and also Former Chief Designer of WIG type SWAN), Prof.
Peng,Gui-Hua(DirectorofHPMVDivision,MARIC),Prof.Xie,You-Non(Deputy
Chief Designer of “SWAN”), Mr. Wu Cheng Jie, (Principal Designer of SWAN),
Mr. Hu, An-Ding (Chief Designer of WIG “750”, MARIC) and Mr. Li, Ka-Xi
(Chief Designer of WIG “XTW”, CSSRC), for their help and using their papers
andresearchduringthewritingofthisbook.
We also wish to thank the following for material contributions and for permis-
sion to use illustrations and photos: Johnny Doo (SSAC), Edwin van Opstal (SE
Technology),BoeingAircraftCompany,FlightshipGroundEffectPtyLtd,Fischer
Flugmechanik/AFDAirfoilDevelopmentandBobWindt(UniversalHovercraft).
Finally we wish to thank our peer review group who provided most valuable
feedbackonthecontentandpresentationofthebook.
ix
Contents
1 WingsinGroundEffect. . . . . . . . . . . . . . . . . . . . . . . . 1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
MarineTransportandWIGDevelopment . . . . . . . . . . . . . . . 2
AlternativeTechnologies . . . . . . . . . . . . . . . . . . . . . . . . 3
TheHydrofoil . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
TheSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
TheHovercraft . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
GroundEffectforHigherServiceSpeed . . . . . . . . . . . . . . . . 6
SomeWIGTechnicalTerms . . . . . . . . . . . . . . . . . . . . . . 7
GroundEffect . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
DynamicAirCushion . . . . . . . . . . . . . . . . . . . . . . . . 8
StaticAirCushion . . . . . . . . . . . . . . . . . . . . . . . . . . 9
BasicPrinciplesofGroundEffect . . . . . . . . . . . . . . . . . . . 9
TypesofWIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
ClassicWIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
PARWIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
PARWIGAttributes . . . . . . . . . . . . . . . . . . . . . . . . . 22
PARWIGLimitations . . . . . . . . . . . . . . . . . . . . . . . . 22
MilitaryApplications . . . . . . . . . . . . . . . . . . . . . . . . 23
CivilApplications . . . . . . . . . . . . . . . . . . . . . . . . . . 25
DynamicAirCushionCraft(DACC) . . . . . . . . . . . . . . . . . 25
DACCCharacteristics . . . . . . . . . . . . . . . . . . . . . . . . . 27
DACCApplications . . . . . . . . . . . . . . . . . . . . . . . . . . 27
DynamicAirCushionWing-in-GroundEffectCraft(DACWIG) . . . 27
DACWIGAttributes . . . . . . . . . . . . . . . . . . . . . . . . . . 29
DACWIGApplications . . . . . . . . . . . . . . . . . . . . . . . . . 32
2 WIGCraftDevelopment . . . . . . . . . . . . . . . . . . . . . . . 33
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
RussianEkranoplanDevelopment . . . . . . . . . . . . . . . . . . . 33
KMor“CaspianSeaMonster” . . . . . . . . . . . . . . . . . . . 42
UT-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
OrlyonokandLun . . . . . . . . . . . . . . . . . . . . . . . . . . 45
xi
xii Contents
Orlyonok’sAccident . . . . . . . . . . . . . . . . . . . . . . . . . . 47
TheDevelopmentofLun . . . . . . . . . . . . . . . . . . . . . . . . 51
KeytoFig.2.20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Second-GenerationWIG. . . . . . . . . . . . . . . . . . . . . . . 54
DesignStudiesforLargeCommercialEkranoplaninRussia . . . . 57
Volga-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
RecentSmallCraftDesigns . . . . . . . . . . . . . . . . . . . . . . 60
Ivolga . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Amphistar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
TechnicalDataSummaryforRussianWIGCraft . . . . . . . . . . . 63
WIGDevelopmentinChina . . . . . . . . . . . . . . . . . . . . . . 65
CSSRCPARWIGCraft . . . . . . . . . . . . . . . . . . . . . . . 67
CASTDPARWIG . . . . . . . . . . . . . . . . . . . . . . . . . . 67
DACWIGCraftDevelopedbyMARIC . . . . . . . . . . . . . . . 70
TheConversionof“SWAN” . . . . . . . . . . . . . . . . . . . . . . 75
WIGDevelopmentsinGermany . . . . . . . . . . . . . . . . . . . . 77
TandemAirfoilFlairboats(TAF) . . . . . . . . . . . . . . . . . . 77
Lippisch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Hoverwing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
WIGintheUnitedStates . . . . . . . . . . . . . . . . . . . . . . . . 85
WIGinAustralia . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
SeaWing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Radacraft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Flightship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
ConcludingObservations . . . . . . . . . . . . . . . . . . . . . . . . 93
3 LongitudinalForceBalanceandTrim . . . . . . . . . . . . . . . . 95
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
OperationalModes . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
RunningTrim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
CentresofEffortandTheirEstimation . . . . . . . . . . . . . . . . . 102
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
LongitudinalCentresofForcesActingonWIGCraft . . . . . . . . . 103
CentreofBuoyancy(CB) . . . . . . . . . . . . . . . . . . . . . . 103
CentreofHydrodynamicForceActingonHullandSideBuoys . . 103
CentreofStaticAirCushionPressure(CP) . . . . . . . . . . . . . 104
CentreofAerodynamicLiftofaSingleWingBeyondtheGEZ . . 104
CentreofLiftofWIGMainWingwithBowThrusters
inGroundEffectZone . . . . . . . . . . . . . . . . . . . . . . . . 104
CentreofLiftofaWholeWIGCraftOperatinginGEZ . . . . . . 106
InfluenceofControlMechanismsonCraftAerodynamicCentres. . . 106
LongitudinalForceBalance . . . . . . . . . . . . . . . . . . . . . . 109
Condition for Normal Operation of a WIG in Various
OperationModes. . . . . . . . . . . . . . . . . . . . . . . . . . . 109
InherentForce-BalanceMethod . . . . . . . . . . . . . . . . . . . 111
