NACA ARR L5L29 Spray Characteristics of a Powered Dynamic Model of a Flying Boat Having a Hull With a Length-beam Ratio of 9.0

7/27/2019 NACA ARR L5L29 Spray Characteristics of a Powered Dynamic Model of a Flying Boat Having a Hull With a Length

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No.L5L2Q

ADVISORY COMMITTEEFOR AERONAUTICS

WAlrlmm IuwolrrOriginally ISSUEDJanuaqy19h6asAdvmoe RewlrictedeportL5129

SERAY~!IWS OFA P(HEREDImwmc MmEL0FAITX12NGBQA!I!HKYYXGAEUILWI~ A ~ RATIOOF 9.0

By RolandE. OJsonandJoeW. Bell.

IangleyMwmial AeronauticalaboratoxyImgley Field,Va.

,. ..,. ....-

NA@i&::--,,,. , .$ -. .-. ... LMWEY MEMOW f~NLL~iiuikbM. -- ~RAToR-Y,. WASHINGTON gasgkymwl v%~..,4.NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution ofadvance research results to an authorized group requiring them for the war effort. They were pre-viously held under a security status but are now unclassified. Some of these~reports were not tech-nically edited. AH have been reproduced without change in order to expedite general distribution.

L -763


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311760136441511. --- - -- - r

NACA ARR No. L5L29NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

REPORT ,.-. ;. ..-. . .. . .

SPRAY CHARfiCkER16TICSOF A POWERED DYNAMIC MODELOF A FLYING BOAT HAVING A HULLWITH A LENGTH-BEAMRATIO OF 9c~

By FtolandE. Olson and Joe W. Bell

SUMMARY ~An investigation of the spray characteristics of a-1~-size powered dynamic model.of a twin-engine flying

;~at was made in Langley tank no. 1. The design wassimilar to that of the Boeing .XPBB-1flying boat, butthe len@h-beam ratio of the hull was increased from 6.3to 9,0 while constant length2-beam product and height ofhull were maintained. The hull frontal area was reducedapproximately 25 percent and the volume was reducedapproximately 11 percent by this increase in length-besmratio.

At the same gross load, the spray characteristicsof the model with a length-beam ratio of 9.0 comparedfavorably with those of the model of the XPBB.1 flyingboat and no adverse effects on the spray characteristicswere introduced by the higher length-beam ratio andsmaller hull..

INTRODUCTION ~In order to select the over-all proportions fcr aflying-boat hull, the designer should know the manner inwhich the hydrodynamic characteristics vary with the. lehgth-beam ratio and with the relationship of grossload to the absolute values cf length and beam.


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. .2 . . . . . .

A few of the effectsbfZem.gth-beamratio have beeninvestigated In tests of series of hull models (references 1to 4). The data given in references 1 end ~ are cuncernedprincipally witihresistance and spray char~cteristics.Curves of yawlng moment and trim llmits of stability areincluded in reference 2 and the aerodynamic drag of hullsof several length-beam retlosis lncl~~dedIn rsference3.An analysis of the results of resistance tests of severalmodel investigations is reported .inreference ~.

Analysis ofthe available data hos shown that increasingthe length-beam ratio of a hull to relatively high vsluesresults in favorable effects on resistance and spray char-acteristics when the length-beam product of the hull isheld constant.. It hasalso been shovm (referencesL and ~)that the hydrodynamic resistance end spray characteristicsere not changed auprecie.blyby variations of length-hemratio when lengthz-~eh product is held constant. dhenthe length-beam ratio is increased while len.gth2-baamproduct is held constant, the plan-form area end volume of the hull decreases because of the resulting reductionof the length-beam product.. ~ie aerodynamic data of i*efer-ence 3 indicate that a significant reduction in ihe airdrag ot a flying-boat hull mT begained by increasinglength-beam ratfo from about to 9 while cor.stantlen@h2-beam prodl~ctis maintained. Tne favorsble effects of highlen@h-beem ratio, therefore, nay be reeli~ed an a reductionin resistance and an imrmo-~exentin sprqf characteristicswith hulls cf equal size cm T,Q;Ie use:as a means forreducing tb.esiz~ of ths h-ullwithout detriment to tnesecharacteristics.

As a check on this anelysia, an Investigationhasbeen undert~ken in Langlay tank no. 1 to deterr,ifiehehydrod~amlc performance of a acwersd dynamic mtiel having.a length-beam ratio of 9.0. The model represents ahypothetical flying boat similar to the Boeing X?E+lextent that the length-beam ratio was increased from theoriginal 6.3 to 9.0 with constmt lan@h2-bean: productand th=t somewhat dif~erent hull lines were,used. In thedesign of the experimental modal, the nscelles, wing,propellers,and tail surfaces were pl&ced in,the samerelative locations and the height of the hull was unchanged.The investigation of the spray characteristics of theexperimental model over the practicable rangg of gross

loeds has been completed and the results are presentedherein. Data from reference 6 and unpublished results.


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obtained during the tests of refere~oe 6 are included to. . :glvear-compar~son.f.these spray charaoterZsticswtth .,. ~-s Ize mode1 ofthethose f e 10., SYMBOLS~... .

CAO .ross-iOad coefflc.ient( ).,. .

XPBB-1 flyingboat.,.

A. gross load, pounds ...~ speed, feet per seoond ....T trim, degrees . ,w specific wei~tm of water(63.5 for these tests~ pounds per cubic foot. .b mwimum besm, feet% length of forebody from bow to step, feetk nondimensional coefficient relatin~ f~rebodyproportions to spray character~ctics

The powered dynamic model (figs. 1 ahd 2), designatedLangley tank model 203A, is a ~-sj.zs mcdel of a hypo-thetical flylng boat esssntislly similsr to the XPBB-1flying boat except for the form and proportions tifthehull. The nacelles, propellers, wing, andtail suzzfacesof the hypothetical flying boat were tho same as thoseof the XPBB-1 and were placed In the sue relativalocations. The dimensions of the hull were derived by lncreasin~ the length-beam ratio from that of the parentdesign (6.3) to 9.0 while length2-besm product was heldconstant. The ratio of length of fore.bodyto length of.afterbody was made the same as thqt ofthe parent design.The depth of the hull waR made equal to that of tileXPBB-1flylng boat. .. .. -

. /,... -. ..


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.. ___ _ _..

4

T@e llnes of the hull are sh~wn in figure 1 and thegeneral arreng?~nt Is compmed with that ofLangley tank model 174 (the ~-s Ize model of the XPB~-1) in [email protected] f&ther conrpsrlsonof the dti.eniionsokmoclels203Aand 174 is given in table I. The forebody chine flare ofboth models was horizontal from tinestep to st~tion 7.Forwsrd of station 7 the chines oimodel Z03A were turneddown and reached a constant value of 10 at station 5.This value was maintained over the rest of the forebody.The depth of step was 9 percent bema. The angle betweenthe forebody and afterbody keels wes 5.4. The Increasedlength-beam ratio resulted In generally finer lines andless cumature thm those of the XPIN+l. The lines abovethe chines were simplified in order to m8intain verticalsides snd thus facilitate modifications to the bottom.

The areas and volumes of the hulls of models 203Aand 174 are compared in the followlng table:.+Maximum 1 - T -Voluwe,Mode1 section ~ Total~~s!l=!l!l. =-i ~l--#=-(sq in.) (CU in.) ~ tetn?ost%* I ~:;? [ ~% t?% I %?g: ~ %i:. - .As compared with model 17j~,tineWle::timnrontal area of.~ro:{imately3 percent, theodel 205A was decreased :.-volume (nose to stern~asi] wss reducsd approximately11 percent, end the skin Px@e-=du@ approximately k per-cent. These vslues wouldbe expected to change sli;jhtlyif the llnes were ad8pted to an actuel hull.

l!hemodel was of built-up construction similar tothat described in reference 6. Two motors turned thethree-blade metal propellers. Leading-edge slats wereinstalled on the wing to delay the stall and make thestall occur at anglas more nearly equal to those expectedfor the full-size airplane.

APPARATUS AND ?ROCEZX.EEThe testiswere made in Langley tank no. 1, which 1sdesoribed in reference 7.. Tho towing gear and some of thetest procedures are described In reference e.


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5T@ prcrpellersof tha model were adjusted to a bl=deangle of 140 and roteted at )+550rpm to provide thrustt?or..hese..t,ests..he effective thrust was measured with

the model at Oo trim with flepssptatOo---l?heeffeotivethrust used in the tests of model 203A 1s shown in fig-ure 4. This thrust Is approximately.the same as thatused during tests of model 174-(flg.1).In-order to provide data from which the approximateloed on the water can be estimated, the aerodynamic liftand pltchin moments were determined with full power and5flsps at 20 by running the model h. the air and measuringthe change in tension in two supporting cables (one attachedat the pivot that was located.at ~ percent mean aero-

dynamic chord O.d+ M.A.C ., and one just forward of thevertical tail!. Data .obtsinedwith an elevator deflectionof -10 are shown in figure.5.

.Suray photographs and observations were made wfth themodel ~ree to trim at constant end accelerated ~peeclsoverthe practicable range of 8rosa loads with the center ofgravity of the model et 2 percent meen aerod~amic chord,the elevators at -10, and the flaps at 209. Speeds atwhich snrey entered propellers or struck tb.efl~..pserenoted for each load. The trim was the angle between theforebody keel and the base line.

RESULTS .W!lDISCU3!310NThe renge of speeds over which spray entered thepropellers is plotted against gross load in figure 6.The most significant part of this spray range is thatbounded by the solid llnes. Jithin this range the bow%lister entered the propeller disks and the greatestdamage to the propellers would be expected.Photographs showing the bow spray of m~del 203A arepresented In figure 7. At a gross load of b5.o pounds,light spray entered the propellers. At a gross load of

z1.5 pounds, this spray was excessive. A gross load of1.5 pounds appeared to be a practicable limit fromconsiderat~ons of spray in the propellers.The range of.speeds over which spray entered thepropellers of model 17)+is shown, together with comparabledata for model 203A, in figure 6. ~is range was deter-

mined from a stu&J of spray photographs (fig. 9) and


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. . .. . . . .. .

6 ...-motlon pictures. Thespeeds at which.the bow blisterentered the propellers could not be disthgutshed fromthe speeds et whioh loose spray entered, but photo~raphsand motion pictures indicate that thess speeds sre verynearly the sine. The totsl speed rmge over which srmayentered the propellers of inodel174. was slightly lessth~n thqt of model 203A erldWRS shifted towmd lowerspeeds. A study of the spray photogrw?hs (figs. ~ &nd 9 )indicates that more spray was thrown over tinetog of thewing of model 174 than ofmodel 203A. This fact is alsoshown clearly in the stern photographs (figs. 10 and 11).The down flare on the chines of model 203A forward of thepropellers probably contributed to this difference.

The range of speeds over which spray struck the flapsof model 203A is shown in figure 12. Photographs showingthe spray on the flaps of models .203Aand 174 ere presentedin figures 10 md 11, respectively. me amount of sp~aystriking the flaps with power appeued to be approximatelythe same for both models. T-herange @f speeds ovor whichthe spray struck the flqs of model 171\ w ss not accuratelydetermined but the photographs and motion picturss Indicatethat this range Is not greatly different from tket ofmodel 203A. The roach from under the affterbodyofmodel 203A wetted the tail extension and tk.ehcrizontialtail at the root (fif. 10). This spra~ w95 very hee.vydurfng runs without power.

At planing speeds the spr=~ from mder the forebodystruck the tips of the ho~iizontsltail of model 203A(fig. 10); without powar, this sprsy was hea~. Simi1mspray characteristics were noted for model 174 (fig. 11)but the amount of spray s=riking the horizontal tallappeared to be less tlhn~or model 205A.For conventional multisngine flying boats, theanalysis of ~eferonce 5 ifidlcatasthat the gr oss lo~d anddimensions ofthe hull are relatsd by the expression

. = kpi 2CAO )\Twhere values of k are given for verious spray conditionsas follows:

. - ..- . .


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. . . 7

L .- . .-. ..

f

. . . . Spray conditlone I k ---- ,.,.,.- .--- ;..-+.--L&t : 0.0 25Satlsfaotory 20 75Heavy but acceptable for overloads ! .0825Exoessive j .0975- . - .-. .A. . . . . - .-.The values of k end the corrqspondlng observedover-all spray characteristics of model 203A may besummarized as follows:

Gross:load coefff.cl~~ ~~------

CAO k I Spray e~aluation.~.. 7 1,8 n.G67i [email protected]? .08z Practicable limit20 i .09 , . Excessive: - - --. ..-. i- -..-..~ ..- -- --- -.This evaluation agrees essentlell~ with what would bepredicted from tho values of the coefficient k derivedfrom experience with conventional lengtii-beamratios.Hence, the possiblo reduction in hull size obtalnod bythe increase h len@h-beem ratio Investigated would notbe expected to have any edverse effect on the spraycharacteristics of an airplme OS the X?BB-1 type.

Theover-sll spray characteristics of the model withs length-beem r.~tioof 9.0 were acceptable up to a ~oss-load coefficient of 2.2 and were excegsive at a grcms-load coefficient of2.b. Those characteristics were inagreement with those obtained with conventional length-beam ratios at the ssme values of the ratio of gross-loadcoefficient to the squax-eofthe forebody length-beamratio.A reduction i n hull size is mqdq possibls by the highlength-beam ratio without 8dvePSp ef.tecton tha spraycharacteristics of a ~ltjengine flying boat. The useof high length-beam ratio thesefore offers the possibilityof reducing the over-all dra~ ofsuch a fUJing boat in

.

1 1--., . . , . . .- ,- .,- ..-


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.

. 8cases wherethe dimensions of the hull are primarilydetemined by sprayand seaworthiness requirements.Langley Memorial Aeronautical LaboratmyNational Mvlsory Committee for AeronauticsLangley Field, Va. .

REN?RENCES

1. Bell, Joe W., Garrison, Charlie C., and Zeck,Hotiard:Effect of Length-Beam Ratio on Resistance and Sprayof Three Models of Flying-Boat Hulls. NACA ARRNo. 3J23, 1943.. .2. Davidson, Kenneth S. M., and Locke, F. W, S., Jr.:General Tank Tests on the Hydrodynamic Character-istics of Four Flying-Boat Hull Models of DifferingLength-Bean Ratlc. NACA ARR No. 4F15, 1944.3. Clark, K. l%.,and Coombes, L. P.: Tank Tests of a

F=ily of Four Hulls of Vqrying Length to BeamRatio. Rep- NO. B.A. 1350, British R.A.E.,Nov. 1936.4. L~d, Norman S., Bidwelli Jerold M.,and Gcldenbaum,David M.: The Resistmce of Three Series of Flying-Boat Hulls as Affected by Length-Beam Ratio.NACA AFUl~~o. L5G23, 1945.5. P*kinson, John B.: Design Criterions for the Dimen-sions of the Forebody of a Long-Range FlyingBoat.

NACA ARR No. 3K08, 1943.6. King, Douglas A., and Mas, Newton A.: EffectsonLow-Speed Spray Characteristics of Various Modifi-cations to a Powered Model cf the Boeing XPBB-1Flying Boat. NACA l!ERNO. L5F07, 1945. .7. Truscott, Starr: The Enlarged N.A.C.A. Tank, andSome of Its Work. NACA TMNO. 918, 1939.

.- 8. Olson, Rola& E., a~ Land, No&an S.; ?@thods Usedin the NACA Tank fr the Investi.gatln of Longitudinal-StaMlity Characteristics of Models of Flying Boats.NACA Rep. No, 753, 1943.


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.. .-.

9..TABLE I . .-----,-,,., .-. .... ..........COMPARISON OF BASIC DIMENSIONS OF

-.. .

MODELS03A MD 1(4Model 174... .

Hull:Model 203A

9.f35yo2791lL. 59.0

Beam ms x h um , in. Imgth of forebody, @.hng~h ofafterbody, in.Mngth of tail extension, in...,Length,oyer-all, in.Length-beam ratio ,Type of stepDepth of step at keel, in.Angle of dead rise at step. .Excluding chine f~~~a, deglncludti~ chine fl-e, deg,Aiigleof forebody keel, degAngle ofafterbody keel, degAngle of sternpost to baseline, deg&gle of forebody chine flareat step, deg

Transverse0.89 Transverse1.1020 2015.905*4

17.905-46.7 7.20 0

18.26167.6519.204

18.26167.6519.204

Area, sq ftSpan, In.Root chord, In.Angle of incidence, degMean aerodynamic chord (M.A.C.)Length, projected, in.Leading edge aft of bow, in.Leading edga forward ofsliep,h.Le;&&g eti~eabove bases

16.4843.04 16. 8*tq8.0 8.318.34 18.35

NATIONAL ADVISORY fCOMMITTEE FOR AERONAUTICS


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,,

..10 i-.

TABLE I- Concluded

COMPARISON OF BASIC DIMENSIONS OFMODZm 203A ~D 174 - ConcludedModel 203A Mocie 174

Horizontal tpll surface:Area, Sq ftSpan, in.Angle or stabilizer t~ wingchord, degElevator root chord, h.Elev~tor semispen, in.LenGth from.2+percent M.A.C.OF wing toelevetors,Height above

Propellers:

fii~e line ofbtia~eine, in.

.Number of prozellgrsNumber of bladesDiametar, in.Angle oftknust line to baseline, degAngle of blade at 0.75 radius,degClearsnce above keel line, in.

393351.6

&599 22.

3*3351.6

2 24 J.4999 9:9

. .

.


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I4.925 PIAX h2UF-6READJH/ ~ % .

I..

9/ (

L) .(

-2/.2s +- 8.s1 51.04

) (

11 1. (- d4=+L 0.89

lf6. 65 w

zo.

FIGURE 1.- MODEL 203R. I!.JKS OF HULL. M IN MM%.


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NACA ARR No. L5L29Fig. 2

Figure 2.- Photographs of model203A.


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NACA ARR No. L5L29 Fig. 3

Jlb=n -

+,,,II14IifModel f74

I1II --- ,1;>

@

2312.!+

3.?044 n

___ ----.\

FzqLwe 3 . Ccqcarison

Um3nq ~~~LI [ORIEW4JTKS

of /nxael Z03A wh% model 174 (XPBB -1).


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23 Model 17b \

15

10

5

oo 5 10 15 a

---

1

1

NATIONAL ADVISORYCOMMITTEE(MAEROMAUTICS

35 wFigure4 .-Model203A. Variation of effective thrust with speed.

Fullpower,4,550rpm;bladeangle,14;flapdeflection,OO;trim,0.

IP

zo.

,:i

1ii


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Trim, degQ oEl Q -..08A 12 Trim, deg,12

/

o 10 20 m w 50Speed,fps NATIONAL ADVISORYCOMMITTEEFU AERONAUTICSFigure 5 .- Model 2D3A. Variation in aerodynamic lift andpitching moment with speed. Full power, Q,550 rpm; centerof gravity, ~ percent M.A.C.; flap deflection, X);elevator deflection,-1OO.


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Fig. 6 NACA ARR No. L5L29

100

60

II I I IW!Y7+//l y] I1- 11

L I I~ ,

9

Propellers / P ropellersclear i clem> \ 1I)\ t-~/\ / ~\qx

NATIONAL ADVISORYCOMMlmEE F~ AERONAUTICS

o Q 8 12 16 xlSpeed, fps

Figure 6 .- Model ~~. Speed range over Which sprayenters the propellers. Full power, 4,S5C)~; centerof gravity, ~ percent M.A. Q flap deflection, ~;elevator deflection, -1OO.

-,--, ,-,, -,, ,,-,... s


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1 Gross load,A0,65,0 pounas !. (65,500 Ib, full size)Figure 7.- Model 203A. Spra y

of gravity, 28 percent M.A

m4. . .Gross load,

A0,81.5 pounds(82,0001 b, full slzej

characteristics, bow, FL. c.: flap deflection, 20

Gross loud,Ao, 91.5 pounds(92,0001 b,full size)

u1l power, 4,550 rpm: cent; elevator deflection, -10

I

ero .

z0.

nbrlOIAL ADv180Rv COMMIT7*E mm AEmmAuTtc#LLMOLI1 MEMORIAL AE~O#AUTIC&L LABOli?O1l - LA1OL1Y PIRLD, VA.


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---= a

v,

~ T,6.3

13.ofps

hmih a.$.,:,::,+#---?Jf


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zoq

c1o3eq


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y18.0 fp!

19,0fps

5

f 7,1010 112

Y 98~ Ao, 65.0 pounds

114.31%%Ijk -,, .-j 2oof ps9ii)~ Ill 120. Ao, 815 pounds Ao,915 pounds

F~gure 7.- Model 203A. Concluded.MATlORbL knvlsonl couM1T7nt ran hnlOmU?lca

LAMoLET uEUORIAL AERONAUTICAL LABOKAT06T - LAROLE1 ?IZLD, VA


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100

w

80

70

60

Spray inpropellers

Model 17U Model ~~\

I /Propellers ~ 1 Propellersclear 1 / clearI I#\ /

\ i1\\ / /y /I

7\ /

\ /

NATIONAL ADVISORYCOUMITTEE ~AEROUAUIKS

L04 8 12 16 20-Speed, fpsFigure 8 .- Model 1~. Speed range over which spray

enters propellers. Full power, 4, ~ ~; centerof gravity, ~ percent M.A. Q flap deflection, ~;elevator deflection, -10.


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~Speed!

i Trim, r, 6.1j~

/f 6.3;

j*6.8

Gross load,~; 65.0 pounds

(65,500 lb, full size )

6.1 6.3

6.8 :6.80

...... ,,.,,.

7.4Gross load, Gross load,Aa, 81.5 pounds Ao, 91.5 pounds(82,000 Ib, full size) (92,000 Ib, full size)

Figure 9.- Model 174, Spray characteristics, bow. Full power, 4,200 rpm; centerof gravity, 28 percent M.A.C,: flap deflection, 200; elevator deflect ion , -100,

NATIOR&L ADV180RT COUUITTIE POR AERoWAUT1C8LAMGLET U8U0RtAL AERONAUTICAL LABoRATORY - LA~OLR? ~ltLD, VA.

z0.

u)


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1. ,,,. 10.OO ~&o,6$.0pounds A.,81.5ounds

zo.

!,9,80 :;,A0,91.S pound-s.: %Pm.Figure 9.- Model 174. Concluded, a

nATIOflALADv180nl couwtmm to~ Acn0nAv71cm 0LAm.m MnuORIAL AsmOnAufIcAL 1.LBou70RY - LAUOLET FIELD. vi. o30q


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Speed,v,

9.0 fps

Io.ofs

11.0fps

6.0

~.:,\,:.* ., .+?$$

z

?;~..p. %@? ...-.-c :.% *i. .. :,.. 6.1

Gross load,---- . . . .

i,.

6.2

>.+ .1,,@* ~r+; z . -..,.-. .. %


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Speed,v,9.0 fps

10.ofps

11,0fps

Figure 10.- Model 203A.

6.2

.~?,-* ..- .. .-. ~.$:: *i

z

.>*. . -\\

.%3

.,

6.5

6.9Gross load,

Ao, 81.5 pounds(82,000 Ib, full size)

z0.r:Na

Spray characteristics, flap and tail assembly. Full %Ppower, 4,550 rpm; center of gravity, 28 percent M.A.C.; flap deflection, 20: m.elevator deflection, -1OO. UATIOBAL &D1180RT COMMITTEE FOB AEBO~ADTICS w

LL90LET MEMollAL AEnOBAUTICAL LAmOILTOIY - LAXSLS1 ?lUD, VA. o


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z

14.0 fps . . ..

, 8.2 9.2AO,65.0pounds Ao, 81.5 pounds Ao, 91.5ounds

Figure 10. - Model 203A0 Continued.


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v,16.01

I7.0 fps..

18.0

$.

10.5

10.6

A.,91.5 pounds ~~Figure 10. - Model 203As Continued.

NATIOMAL ADVIBORT COMMITTEE FOR AEROMAUT1C8LA*GLE1 UgUOR1&L AER9MAUT1CAL LABORATO1l - LARGLtT ?lZLD, VA.

zo.

w&.


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v,19.0 fps

20.0 fps

...,. ,

2i.ofps

Ao, 65.0 pounds

zPc)>

I I .OOAo, 8i.5 pounds Ao,91.5 pounds

Figure 10, - Model 203A. Concluded.NATIONAL ADVISORY COUMITTEE FOR ACROUAU71C8LA90LE1 MEUOKIAL AEROMAUTICAL LABORATORY - LANGLEY ?lXLD, VA.


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speed,v,Io.ofps

:3.0 fps

15,0 fps

Fi gure 11.- Model 174. Sp:ay characteristics, flap

6,50 brtoasprayprohibitive

9.!0Gross load,

A. ,91.5 pounds(92,000 Ib, full size)

and tail assembly. Fullpower, 4,200 rpm; center of gravity, 28 percent M.A.C.; flap deflection, 20; %Pelevator deflection, -1OO. m.

UATIOIAL ADV180~T COUUITTIE ?01 A#lOIAtlTICBLLWOLET MIMO1lAL AIRoIAUTICAL LABOUTO1lLAZ~UY FIELS, VA.


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v,16.0 fps

q, 9.8.0 9.6

18.Ofps

20.ofps

9.5 11,3Ao, 65.0 pounds Ao, 81.5 pounds

zo.rVIrNu)

,,., ..., . .. .,....,. J>

11.8Ao, 91.5 pounds

PFigure 11. - Model 174. Concluded. Pno

UA 71OUAL Anv raoml coumlmm ron AEn0nALi7tc8LA14LH MSMOWIAL AIwO~AU?lCAL LABOLA?O1l - LA80LS1 ?lSLD, VA.


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100

580

60

Propellerspr~strikesflaps IA Bow blister\ / trikesflaps,x x \ x\ f\

\\ * 3I I \SprW clearof flapsII \ I, 11 w

\

\\ I

I I I 1 1NATIONAL ADVISOQY

COMMITTEEFO@~KS

o 4 8 12 16 23 %Speed, fpsFigure/2.- Model 21Y . Speed ra nge over which spra y

st rikes the fla ps. Fbll power, U ,~ rpm; center ofgra vit y , 28 percent M.A.C .; fla p deflect ion, 23 ;eleva t i on deflect ion , -~ ooe

......


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Documents

NACA ARR L5L29 Spray Characteristics of a Powered Dynamic Model of a Flying Boat Having a Hull With a Length-beam Ratio of 9.0