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Twenty-Third Symposium on Naval Hydrodynamics (2001)
Naval Studies Board (NSB)

Page
704
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Page
704
Front Matter (R1-R19)
Modern Seakeeping Computations for Ships (1-45)
Forces, Moment and Wave Pattern for Naval Combatant in Regular Head Waves (46-65)
New Green-Function Method to Predict Wave-Induced Ship Motions and Loads (66-81)
Validation of Time-Domain Prediction of Motion, Sea Load, and Hull Pressure of a Frigate in Regular Waves (82-97)
Ship Motions and Loads in Large Waves (98-111)
Prediction of Vertical-Plane Wave Loading and Ship Responses in High Seas (112-125)
Basic Studies of Water on Deck (126-142)
Second Order Waves Generated by Ship Motions (143-156)
Prediction of Nonlinear Motions of High-Speed Vessels in Oblique Waves (157-170)
Optimizing Turbulence Generation for Controlling Pressure Recovery in Submarine Launchways (171-180)
Hull Design by CAD/CFD Simulation (181-190)
Steady-State Hydrodynamics of High-Speed Vessels with a Transom Stern (191-205)
Practical CFD Applications to Design of a Wave Cancellation Multihull Ship (206-222)
Simulation of Ship Maneuvers Using Recursive Neural Networks (223-242)
Flow- and Wave-Field Optimization of Surface Combatants Using CFD-Based Optimization Methods (243-261)
Marine Propulsor Noise Investigations in the Hydroacoustic Water Tunnel 'G.T.H.' (262-283)
Propulsor Design Using Clebsch Formulation (284-300)
Unsteady Flow Quantities on Two-Dimensional Foils: Experimental and Numerical Results (301-313)
Hydrofoil Turbulent Boundary Layer Separation at High Reynolds Numbers (314-329)
Pressure Fluctuation on Finite Flat Plate Above Wing in Sinusoidal Gust (330-341)
Control of the Turbulent Wake of an Appended Streamlined Body (342-354)
Investigation of Global and Local Flow Details by a Fully Three-Dimensional Seakeeping Method (355-367)
Prediction of Wave Pressure and Loads on Actual Ships by the Enhanced Unified Theory (368-384)
Frequency Domain Numerical and Experimental Investigation of Forward Speed Radiation by Ships (385-401)
International Collaboration on Benchmark CFD Validation Data for Surface Combatant DTMB Model 5415 (402-422)
Validation of High Reynolds Number, Unsteady Multi-Phase CFD Modeling for Naval Applications (423-440)
Free Surface Viscous Flow Computation Around A Transom Stern Ship by Chimera Overlapping Scheme (441-456)
Anti-Roll Tank Simulations With A Volume of Fluid (VOF) Based Navier-Stokes Solver (457-473)
Validation of Tab Assisted Control Surface Computation (474-484)
Experimental and Numerical Investigation of the Flow Around the Appendices of a Whitbread 60 Sailing Yacht (485-492)
Propeller Wake Analysis by Means of PIV (493-510)
Experimental and Numerical Investigation of the Unsteady Flow Around a Propeller (511-526)
Simulation of Incompressible Viscous Flow Around a Ducted Propeller Using a RANS Equation Solver (527-539)
On Submerged Stagnation Points and Bow Vortices Generation (540-552)
Numerical Prediction of Scale Effects in Ship Stern Flows with Eddy-Viscosity Turbulence Models (553-568)
The Experimental and Numerical Study of Flow Structure and Water Noise Caused by Roughness of a Body (569-578)
Large-Eddy Simulations of Turbulent Wake Flows (579-598)
Instability of Partial Cavitation: A Numerical/Experimental Approach (599-615)
An Unsteady Three-Dimensional Euler Solver Coupled with a Cavitating Propeller Analysis Method (616-638)
On the Flow Structure, Tip Leakage Cavitation Inception and Associated Noise (639-653)
An Experimental Investigation of Cavitation Inception and Development of Partial Sheet Cavaties on Two-Dimensional Hydrofoils (654-669)
Modeling 3D Unsteady Sheet Cavities Using a Coupled UnRANS-BEM code (670-686)
Ship Wake Detectability in the Ocean Turbulent Environment (687-703)
An Experimental and Computational Study of the Effects of Propulsion on the Free-Surface Flow Astern of Model 5415 (704-712)
Breaking Waves in the Ocean and Around Ships (713-745)
Numerical and Experimental Study of the Wave Breaking Generated by a Submerged Hydrofoil (746-761)
The Numerical Simulation of Ship Waves Using Cartesian Grid Methods (762-779)
Radiation Loads on a Cylinder Oscillating in Pycnocline (780-791)
Wave Resistance Computations - A Comparison of Different Approaches (792-804)
Computations of Nonlinear Turbulent Free Surface Flows Using the Parallel Uncle Code (805-819)
Submarine Maneuverability Assessment Using Computational Fluid Dynamic Tools (820-832)
Simulation of UUV Recovery Hydrodynamics (833-847)
Reynolds-Averaged Modeling of High-Froude-Number Free Surface Jets (848-862)
On Roll Hydrodynamics of Cylinders Fitted with Bilge Keels (863-880)
Combining Accuracy and Effciency with Robustness in Ship Stern Flow Computation (882-896)
An Unstructured Multielement Solution Algorithm for Complex Geometry Hydrodynamic Simulations (897-909)
Ship Stern Flow Calculations on Overlapping Composite Grids (910-926)
Study on the Prediction of Flow Characteristics Around a Ship Hull (927-940)
Analysis of Turbulence Free-Surface Flow Around Hulls in Shallow Water Channel by a Level-Set Method (941-956)
A Design Tool for High Speed Ferries Washes (957-967)
Flow Around Ships Sailing in Shallow Water - Experimental and Numerical Results (968-982)
Ship Stability Study in the Coastal Region: New Coastal Wave Model Coupled with a Dynamic Stability Model (983-992)
Waves and Forces Caused by Oscillation of a Floating Body Determined Through a Unified Nonlinear Shallow-Water Theory (993-1005)

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OCR for page 704
:s~ s: Experimental meLsurcmcnts of tbc Eclair Marc, and thc near- and ~-Ocld ~avc geld, both wig Id Bailout go Bowl propcllct operand, Marc ob- ained Mom ~ surface ship model reprcsobting thc pr~- b~n~ design of ~c DDG-51 ~11 farm, reprcsantod by OTMB Body 5415 Wave height m~a4~remcnts pa CDT Model Basin {DT~B) using No disarm ~chni~e~ The best toch~iq~o uses c~acb~co probes ached to the side of the modcT basin 10 obtain longitudinal Sac cats The second tc~n~e uses ~db~ probes synched to ~ ~~crsing system at the Berg of ~d modal to measure the spruce awe Meld babied 1hO model. The d~1a Mom tag ~ccb~nical prows are used 10 gC~C[- ~1e ~ ~~ bbijbt 1~po~by map. The resume Mom boa mc~suLcmb~t techniques arc used as a basis ~< colon Aim co~u~tiob,1 fluid dynamics (CFD) prodictions. Froc-sur~cc predictions Mom Mississippi S1htc UniYorsi}'s UNCLE code, Aim s propeller bc~ ~rce-modol inco~or~tod, are documented sad the Lands ago cowered Nib the c~porimcnt,1 data. ~ OUR f~S~c Fad Amid ~t ~~- d~ing ad ~ansitioning ~ ingests R~oId's Avor- ~g~d Drier StoLcs ad Pod Flow cOm~ion~1 codas ~~~ in 1995. Coda iil5 Ads chosen is s rcprcse~titive navalod~tstsnthuI1 Cam on which a ]joroussetotc~phpitotlubcs~s~ollasv~lociLc4~stem oflhcopor- atig~ propeller measured limb Lace Doppler Vcloci- mcRy Th~dg~bas~c~ be~ccossed ~om1bc Coda 54Ti Gab sin ~ hup:~.~.~50~.n(1/541i. Tab papc~docu~nts Me ~cc-sur~ce ~avehoi~btd~1~ob- ~inod on ~o~ppcndod modct boa thopropellcr~opcradng. As pad of We Ova Frce-S~cc lni~advo, computabonsof1bc 6~csnt~cc Cow andsub-sur~ce vetochics Gore obtained on Me bare hull modo1 Bailout ~~ R~NSprodichoncodos,LNCLEsndUnivcrsi~of loams CPDSH1F. in addi~ontothc RANS pr~dic- (ons,pote~islOow codesincluding SWAN,LA~P, andU~DELTA,~orgalsouscitopredictthp~cosur- ~ceOoy ~roundthc modct Th~resu~sof~bLe~ ~Ion, Dig Sons of Tic predictor codas arc Hoj<15415 ~asbuJ1Of~god ~ 1960 ~ ~ anew scale Who of24.824 sndis,cprcsebtad~c ofa mown nave cohabit hug Ann. E~c~dn~ Was r~s~n(~ ~> yS~m~ of Churl ~n~,bc~ ban husband limb ~pcDd~gescanb~do~tlo~d~d ~omth~ ~odeli415 gab Me. figurelsbo~s~pbotog~aphof thirsty ofthS modal, Ally o~tEtl~d ~fibisc~pcri- ~~ ~~bk Ids 0~ ^ ~~ ~~} Tbomodolbss~vl~ ~dUcrs~hichares~tat~ leaf zero dQgrces7~14ti#c to ~~ modal c~ntor~n~. The - ~ ~ ~~ ~$^litor gads 3.2 ~ ib diameter and 2.5 mm in h~i~b1 acre aged to ~c ~dc1 in accords~c Aim bu~bcs find Allon (1951~. Flgurel- ~odali415yilbRomov~k App~odagos (sb~As~ndstrutS) uring1be propelled c~perimen1~ the modal asD1lcd Aim dcsignpropeUersdesignatodaE sat ~ ~~ ~~ ~~ His

OCR for page 705
propyOcrs 487( Id 4877. fbcsc ~cpresont 5.49-mctcr ~ll-sc~lc diim~tc, propollofs. A photograph of ~c pumps on We modal is son in Figure 2. Fipurc 3 oboe 4~ ~dmc~ic vow of the ~p~n40d moJet Ta- blc 1 provides modal dimc~sions and other particulars. glued 1 ~ Isgmp~ic Vow of Modal 5413 Tbc c~pprim~nts described herein arc ob- t~in~d bow #~ and Befoul ~< propellers operand. To obtain ~~ most Cute #~-sut~cc mousuromcnt6, in Sac exporimepls ~c modal Was mounted in s fixed aim condition co~e~po~dlog ~ ~c avid ~ of Me model ~ ~ Frown aver of picker p.28 (2.00 Basic) or 0.41 {3.10 ~i~c(~. Wh~n th) mpasurem~nti ~ro ob- {~n~d ~i~ ~ OCR for page 706
the ct~cult Card. with the copper wIte completely InSu iated ~~m the water, ~e sens~g element behaves as capact~lr wed ogle plate be~g ~e copper wed, the $~- ond pl~e the water' arid the wale ~nsulLat~n act~g as the dicIc£~. AS waves in ~e basin change the Sub- merged height: of ~e sens~g cIe:~, they change the ef~e capacitor plate s~' ~~:~h tesults ~n ~ change tn capacitance. 'the change {~ capac~e 1S propor- :~l t~ t50 ~~ 6~- 87 ~~g ~~ If ~Y~07 ~ V~y~ng capacitor' to ~ dmIng ctrcult' ~ d.~- vOltage IS generated ~~t ~s d~y proport~! to ~e c<~citance the wavy height belong . ~ wave boom (~s section~' canti{~: e baSI~ ~,811 ove,{ the water' provIdes ~ stmc ~~ 4~ch the ~~ ~s mounted. IFFY wave boom e;~s 6~S 'n Mom the tas~n wall ~ -d Un! sIlde wIth ~ at~d torIzOnt~ bar iS mO-~d ~ crt~Q on the wave boom. The capac~e probes, un~slide. The un~-~de atiows precise placen:~s of the probes, \~1 pOsition, probe emergence' uSed £~g static cal~tan of the probes. Figure ~ shows the IOngim61~! ~,~e cut hardwal.e ~ place ~ the ba Ace. ,~O probeS were uSed ~r thiS cXpenment. |~e placements of the probes are referenced to center il~0 0t t~0 ~7 ~~ pt050 ~~t ~ 60i.~g i,}~6 and probe number 2., ou~' The probe placements ate pl-~d tn Table 3. ~ ~ ~ ' t't: ''t< £ ~ I'! t< hen the ~6 P0~ndic~ ot :~e ~,~l ;~h prede0~d distance honh ~e wave probes. ~ ~ 33 Mod pentIt~ claSs computer, us1~g an ADC488 ~ ~ blt ana fog to digital (~) cOnve~r collectS =d ,3~e,8 the . Table ~ ~ Lon,81~l WaVe C~ Probe LoCatIonS T~rs~uso Dis s.oe JO n Mode] CenterI~n~ t MY 0.~6 m 0.73 . _ | ~ 5 at 2. 5 InS1~ callbratIOnS al.e per~: aner ~e con~n of ~e ~~t Semis. In order ~ callbratc ~e probes, ~e motorized un~-~e is immersed in 2~-~m ~~er~'~s ~r ~ tOt~ Of ~.~2 cm. ~ 'Data Is cOllected at each il~emen:t ~r each of ~e probes. ~ sought line :~t ts per~d and ~ SIOpe tS calculated and stored ~r A. :~: is:: :~: ::: :~ ::: each probe. The ~~ cal~:ra6~n permits caT~n of (he probes' the signal cond~g ampl~, ar:d the A/:D conve:~r as ~ system. Figure ~ - Longitudinal Wave Cut Set Up Operating Proced~S Paste zeroes are co11~d ~n cal~ water Are each act. The mode! ~s ~~n ~~ past the probes at constant speed. As the mode! approaches the test SectIOn' ~ Strip of reflective tape positioned on ~e car- tinge triggers ~ photosenso:r placed at the s~de of the bas~n which sta~s data £~. FLC POSIliO~ O:C (~C photosensor and the duration of 66~8 00~100~ is ~~- iusted to inSure that ~e max~) amO~t Of data < collected before tank ~7~. tc~ctions occur. Data ~s 61t ~ ~ TO HZ wI~ ~ ~ pole BeSse] fIter and cO! |~6 Q: ~ S8~:Og 731C O:? IOO HZ ~{ 20 lO 30 SCCO~S 60:~dIHS O~ I~! SPCC~ 8~6 PLOlOSC~: POSI!~. Oata analys~s ~s performed on the PC aDrer each mn -First, calibrations are applied to the A/D voltages, and ~en the prose zeroes are bed. The data ~~m each probe ~s ~~n plot;~d to en$~m ~~t the measurements are ot good q~-~W F~r anal>~s on ~e long~-~! ware cut data ~s oOcn per~d ~n Order to co - ~~e ~~e WaVe spectra, and w8,\~e p~,(~l,~, ~~. :5 in 0~65 ~~- ChanIc~ PtOb~s ~~t cOnti~Q Searehes ~r ~e qee St~£~< :~C SCO$~g ClC~t OittC piOtC IS ~ 0.381 diameter, 5~$ cm Iong sta~s steet Bore. The w~e Is mounted 1n cL copper ~be that makeS up ~e body of the probe. ~ geared racks ~.~6 t~ t60 ~~ t06y, By_ |oWs ~e probe to be ]~lYOH up and do~' US BY ~ Se - ~~. opening and cIoSIng ~ cItcult 60~YCC the probe and the water 1S sensed by an CICC~£ C17 cult whIct Polyps ~e semomotOr. When ~e protc iS not 1n cOntact Why the Why{ St1~O there iS an Open ~ ~~ :::: :::: :~ i: :::: ~

OCR for page 707
citcuit ~i th~ servomo10r ~ivOs ~a probe do~ to- ~ardA 1hc s~cc of thc ~ter. Oncc cont~ct is made bc~ecn tbc pr~e and ~c sn,~ce of th~ watc~ a closed cEcuit is ~ensed ~nd ~c protc ~ ~iv~n ~p, ou1 of tbe atcr. Tbis proocss i$ ropdatcd continuously, causing 1bc probe 10 oscHl~> ~^d tho 60o ~ur~cc at ~- proxim~ly 20 H~ lho proLc ~ conn~ct~d to a pot~n- bomotor tg~t ~cks ~s position ~long tbc z-~xis (~avc h~i~. Ptob~ poskion is roco~dod h~ a s~-lc and hold circui1 during ~a 1nstant 1bc probe makes inid~1 contsc1 ~i~ ~e wa1cr sut~cc. Thi6 mi^~r of s~- p~ng p~b~ po$]ion ~lovi~s position a~or Fom ~- niscus c~cl~ duo to sur~cc 1ension. E~perlme~t~1 Setup To cr~to a topo~~hy of thc ~6e sur~co tbe stom of tbo modct ~u~ prob~s arc mo-ed to- t on a b~sokol ~1~ct~ed to a ~i-slido. T\o p~otes o~ ~ ~ ~ ~ ~ ~ ~ cc~prlin~ of th~ mdd~l, ~i~ s i.08 c~ spacipg b~- #bon prob~s. Th~ pr~b~s opor~g >ghiAd ~odel 3415 cEn be sc~n ln Fi~urc i. Tbo a~y of probos ,re ~ an XY-~ivc~e ~at is mou~d ~ ~o csr (ago ~t ~c s~rn of tb~ ~odcL T~o s~igg pot~ aL th~ i~c~se ~rc used to ~ck tho longi~dinsl ~ansvo~sp (~) pos~ions of ~c p~obos. 133 ~H~ 486 co~utp~, usi~g ~D AOC438 16-blt {D c^~ collocts ~3 ^~$ ~ ~. ~ -( collec- tion co~ut~r is nc~p~ed ~i~ ~ 35p ~Hz >~$~m 11 l~p c)-utcr th~t i~ os~d ~r d~< ~aT~is ~d plo1- ~r ~ ~ ~ ~ ~ ~ ~ ~ B~ S1~1ic cslibr~tions arc per~d on ~a kkerp~bes ~ ~cl~,phor~ ~oe~pch~. Tbo ~re poskioned ov~t ~ cont~incr of w~r, and allo~cdtotrack ~ecaIm hc~s~ceastbouni-sTiddis ~vcrsod in 2.54-cm idc~cmcnts ~, a lot~1 of +7.62cm. Dat~iscolloctedato~chincromcnt~rosch of ~c proLcs. A ~aightline [tisp~r~nncd and a ~opcisc~lculatod~ndstorod ~reschproDc. Oper~g Procedures The ~rd most probc ~ aUg~cd Tongi~di- n~iy (X) snd ~-svcr~e~ (Y) ~hh th~ ~R pe~cndicu- lar snd con~rLnc of 1be model rcspoctiv~ly. Tho longi- ~din~1 ~nd ~snsYctsc s~ing pots ~ie ictoed ~1 ~is Io- cat10n, ~d ~11 ~~e mc~surcmcn$s arc re~rc~ccd to this posiFon. ln order to collect ~e cats n~edod to g~n- er~tp s compIctc topogr~by of ~e stem ~foa, ~e area is dividod into a ~mb~t of ~nsvcrs~ c~s. 0~c ~sns- vcrsc cut coll~cts in ~g of 15.24 cm by 1.32 m. S181E ing ~s clo~c to ~d stb~ of ~c m~d~1 as possible (1.27 c^, succoss~vp traD$vcrso c~s ard ~dc ~]h ~ ~d~ v~ndomen1 of 20.32 cm aloq~ 1bc ~-4{is be##ch cut~ For ~L <~cnt ~e co-Te~d ~pod ~ea - uYed T .32 m by 2. 38 m. Thp po~$iblc q~mb~r of tr~nsvcrsc cuts per ~u~ dopend~nt on mQdb1 spp~d. Oncc ~< nu~ar of avcrsc c~ts p~r ~n is detc~ined, ~ co~nd E1c is ~cnc,<1specd d4tu and 1be zoro~spcod d~la, and thon s~ac~ng out tbe 7~ro-spoed data to produce ~ ~ct of z~ro-co~nsatod d,1~. Nc~t, Oltcr cbemcic~1s arc calculated ~r a BuLo~orth 5~, witb an optionsl nu~cr of pol~s, choso~ By ~e use, gn ~is case, 3 poISs ~etc sp~cl~ed.) Tbc ze~ compchs~t~d protc data is ~en C11cred in bo1h d~ections 10 ehminatc data phase shi~s. Tho no~t ~cp tp~c ploU~g, ~ to ex~sc1 d~1~ hom ~c dsts sot A grid ps~e~ is e~tablishod ~ith ~D x-value at cve~ longi~din~ probo pos~ion ~nd ~ y- valuc ~hich st~s ~ tbe beginning of ~acb tr~svetsc probe pos~ion and ~xtc~ds to ~c ending probe po~10n, in increlnents of 0.5 cm. Probc d~a clo~cst 10 ~C de- sked grid loc~dons ~re cx~ctod ~om tbe datu so1 and savod. Tbesc dsta arc ~cn placed in10 a ~st ~r ~ ~ s~ s~ ~ ~ ~ ~ ~

OCR for page 708
plOuiOg the stem topogr~by cotton maps, using TECPLOTso~wstc. Itisi~ort~tono1c ~stibe~e contour maps ~prcsent ~c~vcr~geofstimc-va~ing dathset~itban WAS v~ri~bon gout Me moan contour Ib~coord~t~sys~om ~r~emeas~o~ntsi~ di~n~d~i~thcx-axlsb~ingparaUcl 10 ~0 modolcen- 1crUne, go ~~xisst~s~ships Ad ~cz-~xisp~cn- dicular 10 Me calm ~stcrsud~ce. Alldata Ad axes b~cbecnnon-dimensionsUzodus~gtbc modelleng~. The ~r~s~dp0~endi~larisd~notad~/L=0,~d~c sRpependicul~4sx/L~1.0. Lon~1tud1~lW~veCut~e~suremeq(~ Lop~l~din~1 ~~0cJ1s far ~odc1541i limb and wi~outpropclldrsoperahng,atFroud~numbcryof 0.2Rand0.4T,rrcsbo~niuFig~cs6~nd7. Alongi- ~din~lwav~c~ c~nb~cb~ractctiz~dby ~~ ~~vesor av~systoms. The ~[S1 ~sve~thc"bow w~vc/'gcn- e~tedby +obo~)dshould~r. Tbebow ~sv~is~l- lo~cdbythe~4vos~cne,~od gong Me mid~bo~,~6 low~dbya'#tc~ ~ave/'g~ncratodbythcstom. Lastly a~otof1ransvcrs<~v~sdec~inghebind~cmodel~c obscured. A1s Froudc -~tarof0.2S,attbeinncr prob~locsbonof~Bof0.73,1bo0~tc1Ofpropul~onh domin~ntin the ~an~versc ~~c system ~b ofthc modeL WE 1bo propcH=~ opct~ing ~ 436P, Bare is ~ J0 p~cntinctc~sci~ Sac b~svcrse ~~vc Nimbi once Ma ~~topel~d~sc. Tboc~tctof go oDct~iqgprop~llcri~pa<(cul~rlynoticeptlpipthe~m- pli~de oftha stom ~~c, ~bich is au~mcn~d by 20porc~nt )itheo~rprobaloc~bon{)Bis2.44~c cf~ctotpropulsiononiEcsipm wavolsloss;onIy~c- cou~in~ tar ~ incroaseoflOparcont T6orc~slso~ noticeable pose AIR in tag E~nsvcrsc Lava system by ~aunprdpebodandproppB~dcondidon. Tbc t~svcrse Marc Susan of Be propcHed modal is shiReda~by12percentof~c ~snsvefsc gave length (2~V2/~.Tbis pbEkc shiRi~ morc~viicnt~tl~g~val- uc~ofx/L. At~Froudonum~erof0.41,~tcrothcpropol- ~rsoporaloat772 RP~,prop~sionha~a minimaleb Actor Be ~svosys~m>iccoundng ~ronly~6pc~ contincreasciniLcs1~ ~avoAmpli~dc sad 2pctcont increase in ~C s~dcof~e~ansversc~vosys1cm atiDcinnc~probeloc~bon. Attbeou1crprobeloc~bon, propulslonacco-1s~ra9 pOfC~t incresseinthcste~ s~ca~do~ndancgligiblcincr~sscin ~o~mplL d~sofibe~ansversewavcsysiom. A1tbisspecd,tho ~tgcs~m ~^c ~ domina~dby Defog around Sac Ransom s~rn,so ~coB>ctoftheopcr~ngpropcHcrs islessovidcnltb~ ~tsFroudenumborof0.26 The eAtctotpropul~on on~bolon~din~1 av~cutsgc~cra1odby~ modclreprasentin~anothcr co~anlbuD ~n~basbeensbo~ntobc an scenbcre ~r~odol5415.Tbisd~la SC1 iS prcsentcd in Lindenmn~sndRatcif}~1989~. A companion ofibe pad and ~pro- peD~dncar-Celd ~avosyst~msataFroudc Crop 0.28, grasped Aim ~c ~biskc~pf~c, ~ Sherwin Fig. The diCtrcnceLc~Vecn Me ~~ conditions h~sb~cn ~inti~edin F1~rc9. Ffopulsionincrc~scs bc~av~an~dc~ong ~cstern~av~c~cstlineon cordcrof3ipercent.1n ~eregionb~bi~d Bested, ban an AL of1.05 and l.li,propul~on enacts account~rlocalincre~scsin ~sY~bcigbtsof25to35 pc~ccnt )i this Froude number Be dog issdU ~L tadbedfothd~nso~. Ata Froudc numberof0.41,the Hansom is completely clearly and the Bow converges iD bighly ~kbul~ntre~ioncovcrin~ ~narc~of0.T5sb~ length longitudinally by 0.05 ship lea 1rans- vcrscly. Fi~elOsbo~1b~di~cDcosductopropul- (onin ~e~vc ~cIdLebini ~ctr~som et aFroude numbarof0.41. Figure 1I se~cslo quanta gosh di~tranc~s. Tbedi~trcnce~ Me 10 propulsion atom 0.005 0.005 Q.O~ 0.003 0.0= Q.OO1 a <~01 ~02 ~03 .004 ~,006 OOS 0~06 0.005 0~04 0~03 0~02 0.001 o <,001 .002 <,003 ~.004 <~05 ~1 non Fi~e6-lShcEB>ctofFropulsionon the Far-~cld WavcSystcm~s~easured~itbStudona~ Capacitance ProCcs,ataFroudonu~terof0.28 . ~ ,_~ 1__ koala Raw ~ -- 20 kn^ propelled 20 kn^ unp~pellod . ....... _ ... __ _ - ~L

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0,015 nine 0.0 1 C In . . ~ _ lt ~~ I. . . . I1 ~ <1\ .. ~7~ ~I\ /\ /\ ~ ~ ~ 1 ~ ' ~ ~ ~ f ! 1 f < < <{ \. OCR for page 710
~ecsuromcnt unccrt~in~ bus been ictc~inod far bow tbc longim~in~1 Wave cut and ~bisk~r probe data, ~ catch of +c Go spends ~bc~c data Marc on tained. The analysis is in accordance limb standard uncchain~ an~lysis pmctic~s of tbe ~Goidc to th~ Ex- pr~ssion of [nccrt~in~ in ~c~surcmcn1~ ~s docu- mentcd i~ 1993 by ~o In1~nsb0nal Organizadon ~r St~ndardiz~don QSO), ~nd c~plsi~od ~ber in A~S1>S~E (1998) ~d tbe AIAA Stands~d (1998~. Dcta)cd oxplanabons and c~s-Tcs of the ~CCEtBiD~ aDalysis s~e givch Coloman and StcoTc (1998~. For cacb speed ~pd condbion at -~h ~vo c~ ~ere con~ctod, ~ mc~ ~-e ~s calculat~d ~om tbc ropeat p~sscs th~1 ~cre collccicd. Tba me~ ~c Lom ~osc r~peal pisscs ~s c~cul~cd ty avcr~gln~ //L (thc ~avp boights~ a1 cacb X/L, ~bc longitudin~1 dist~cc ~pm 1hp sh pc~cndlcul~{ S~v~n ~cpo~t passcs ~cre collcctcd at s Froudc nu~r of 0.28 ~r ~a propeEcd and unpropcHed condihon, ~d cigb1 rc- pc~t p~ss~s ~ro collec1od at a Froudc nu~c, of 0.41. For ~0 ~k~f p~obe d~ta, ~=s~crsc c~s ~erc us~d to p~lcula~ ~e ~o~ ~av~s in ~c tr~sversc dir~ction (Y/L). Six r~ppat t-$ ~erc obt~in~d at s Froudo ~m~ ber of 0.28 ~d nine at ~ Eroubc ~r of 0.41. Thc proci~on ~mbs arc based on mc ~tand~d doviations of ~e ~sve. Tb~ ~rd devi~ion a1 each X/L or Y/L lpc8hon is c~lcul~ed ~en ~t me~n ~sve is svc,~cd iom ~c rep~a1 pds~es. Tbc sta~dard dovia- (o~ ~mss ~e ~o~ ~~ ~c -1~ ~ ~e p~peL s~d~nt-t v~luc sc~isr hom ~o 95~ ceft~i~ C~ 10 pro~ce ~c preclsion Iim~s. Tbesc prCcision bmbs, vs~ ~i~ th~ posibon in ~c ~avc, usuaby groater it ~c cres~ and Roughs of ~a ~vc tb~ at tbe zc~-c~ssings. The bias limit is d~tc~i~ed by calibtstions donc insi~ =~ ~ sc~l,~ sppligd across thc entirc ~can ~ave. Tho unce~ain~ is co-~cd by ~c rooG sum~squarc of tho bias ~nd prec1~ion [m~s (~Lo com~ moIdy re~od 10 as th~ systemadc and random c~ors~ Tbe combin~d ~cectai~ ~r ~c propcllcd a~d unpropellad con~ions arc prcsented 1n T~1c 4. Co~ut~io~s ~re por~cd ~i~ thc U~- CLE codc Pbm ~lssis~ippi Sta1c Universi~. Tbis dme-accur~e, stc~ inco~ressiblc ~S codc bas been usod c~tensivoly 10 computo lbc ~cc-s~cc ~ov Oold ~o~d snc~cc ship mod~k. (Bcd~u, 1998# A propellc, body ~rce mod~I ~as intro~ced in ~e code to co~ute ~c ~cc-sur~cc elcv~Cons ~itb ~ opersEng propcHer. This bo~ ~rcc-model ~as ~n ~ s T~le 4 - Su~~ of ~o Froudo Nu-crs Fn=0.28 {~/ ^~ r ? # /~1' _ F~0~41 [~;~7 -~ C~ 3~ #^ _ ~ (' u _ ,,, ~_. ........ 86.0 14.0 . ~ 64.8 35.2 . ~ . ~ 66 4 33.6 32/ _ ~ . Bias E~r (y of tolal ~c=1~n~ Preci~ion (~ldom E~or (~ of total ~~n~ (~ of l~g- est value) 2.73 4.60 3.54 9.20 . r ~e Froude n~, of 0.28 cond~ion. Tbc body ~rcc propulsor module in U~CLE is basod on ~c model of Yang, ~rjv~h and Sundrsm (Yan~ 1990\ Tbc pre~chb~d body ~rces =c ba~ed on ~e ~rust end 10rquc coofRcicnts as ~ell as an ~s ~ cd c~culstion dis~ibution. An ~quate humbcr ofg~d points l~USt bc prcs~ntin ~c propoll~r plane to cn~urc good rcsul~. Th~csult~arc~bo~nin Fi~u~12. lnthc~c~iona~of n.d n.~ o. n~ ~._.- ~< Z/L >.009 ).pO7 1.006 ).003 j.OO) #.001 J.003 Figurc12- U~CLE Freo-sur~cc Co~utstionsat Fn=0.28 W/bout(Top)and W bb(~o~om)PropcHc, Body Forco

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the stem these is al increase i file mplitude of file waves, although not oser as g eat an extent as is sem i the experimental data The body force-model also pre- dicts an imrease in the mplit de of the stem wwe crest The magnit de of d is increase is consistent wish that seen i the measurements obtamed at a simile Froude n mbff CONCLUSIONS This data provides a comprehensive documen- tation of the effect of propulsion on the wwe system around a naval combatant hull fomm The use of bodh near and far held measurement sy tems results i a thorough msppi g of the wave held around this hull tom The data presented here how Hat there is a greater effect of propulsion on the wwe sy tem near file model at Froude number of 0 2S than at a Froude n m- ber of 0 41 it is likely that d is is due to the different nature of file hyd odyn mic flow at each of these Froude numbers At a Froude n mber of 0 2g the flow is still attached to the transom and file effect of file op- erating propellers is to change file chamctffs of the local wave system This change is manife ted as an i crease in the maximum wave heights along the tern wwe crest li e and an increase i file wave heights behind file model At aFroude n mber of 0 41, where the transom is d y, the flow held is domi ated by file flow at file edges of the transom converging astem, and the effects of the operating propulsor are mailer than were ob- se~ved at a Froude number of 0 2S UNCLE computations wish propeller body force show simile trends of the effect of propulsion on the wave system as file experimental data There is a visible imrease in file mplitude of the stem wave :- . .t and an i crease in file mplitudes of the waves i file region astern ofthemodel It is hoped that this data will continue to pro- vide al insight i to file effect of propulsion on the hy- d odyn mic flow around transom stem models, and will be used to evaluate file way in which computational fluid dm mics prediction codes model propulsors i the computations 8 ACKNOWLEDGEMENTS The author wi be. to think Jim Rice and Ian Mut ick for pled suppo t during file collection of these data sets Scott Percival and Steve Fisher helped pre- pare file figures for this pape' Much appreciation goes to Willi m Bo ton and Peter Congedo documented file hull fomm and the hyd odyn mic flow, photogmphi- cally Finally, l w uld like to Hank Edhv Rood at file Office of Naval Research for his vision which recog- ni ed the conhibutions Hat CFD predictions could make to hip design and his commitment to obtami g the be t possible experimental data for validation of these prediction codes REFERENCES A AA (199S), A AA Standard S-071-1005, Assessment of Wi d Tunnel Data Unce tainty ANSI/ASME (199S) Standard PTC 19, Te t Uncer- tainty Beddbu, M, Y. Jiang,, D L Whitheld, L K Taylor, and A Ambshahi (199S) "CFD Validation of file Free-su face Flow A und DTMB Model 5415 Us- ing Remolds Averaged Navier-Stokes Equations," Third Osaka Colloquium on Advanced CFD Ap- plications to Ship Flow and Hull Design, Os ka, Japan Coleman, H C, and W. G. Steele, (199S) Exp~simen- tation and Unce tainty A alysis for Engi eels, 2Ai Ed Hughes, C and J. F Allen (1951) "Turbulence Stimu- lation on Ship Models," SNAME Transactions, Vol. 59 Lindmmuth, W. and TJ Ratcliffe !1989) "Kelvi Wake Measurements Pe to med on Five Su face Ship Models," DTRC -89 Dig Ratcliffe, T. (199S) "Validation of Free So face Rey- nold's Averaged Navier Stokes (RANS) and Poten- tial Flow Codes," 21 Symposium on Naval Hy- d odyn mics, Washi gton, D C, 1998 Yang, C-l, P. M Honsslch, a d P. Sund m (1990) "A Navie~Stokes Solution for HullRi g Wing- Thmster Lnteraction," Eighteenth Naval Hyd ody- n mics Symposium, University of Michigan, A n A bor, Ml

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DISCUSSION H Chun Pus m Nctiorul University, Korea When you mecsmed the wave profiles, w re the models tree or fixed? f th models were fiee, w re She sirJcages Ed trims of the two model conditions wish Ed without the propellers the same es each other? If they are the same, how did you cdju t them? AUTHOR'S REPLY Ibank you for your import mt questions regardmg the sewage Ed h im of Model 5415 For both She ion m~dn~l .. n ve cut experiments Ed the stern topography experiments, be model was f Fed et c sirJcage Ed trim corresponding to the trim She m odel would achieve et c given Froude mmmber he fi ed trim was chosen to be that cssumedby the mmpropelled model he m odel was then fixed et His same h im when the propellers were operctmg Obtaining date around the model et He same trim condition, with Ed without propellers operctmg provided c self- consistent set of date for CFD validation

Representative terms from entire chapter:

odyn mic