.

.

/’

,NATIONAL

16 u N4~

ADVISORY COMMITTEE

,,

FOR AERONAUTICS

WARTIME IuwolrrORIGINALLY ISSUED

J%,I@18~ 1946asAd’wmceRestrictedReport

::.

16E22 ..,.,,

~TIHISAN DAN AIXSISOF THREE ICAFOWM)IAME?ER

TEKEIM31AIIETRACTORPROI!EUER3D13WEKUW IN

PITCEDISTRIBUTION

By JeemGilman,Jr.

//

—

LangleyMemorialAerm-utioalIabomtoryLangleyMeld, Va.

#,.. .,, ,.,...,

.> “.’ -~ ..’.”’.,.-”,’ .,,‘r .;

‘“-’”NKc@~!~’;-’:”’’y.,%ifp+:.!.,..’

.,. \..,’,,.. “~ :“.. ~ ~ ~-,F.-@##hb,., ~ s *o@J’ .@i~., ...-...._= WASHINGTON,., @@q *:f@~:r,A. “

., ~aw+ ! ,

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 umder a security status but are now unclassified. Some of these reports were not tech-nically edited. All have been reproduced without change in order to expedite general distribution.

31176013544329—. .—. -_. ——- —

. .

NACA AW? l?o..

.

L6E22

NATIONAL ADVISORY COMMITTEE FOR ~RONAUTICS.

. . ....

,............... .+V~?@. ~s~~~~,~&)-RT , .... ..” ----- _...- .. .. .

WINZ3-TUUiEL .TESTi.AND MWLiSiS OF &REE l.O-iOOT-DIANETER..

THREE-BI+W TRA&OR PROiELIERS’DIFFER1iTG IN “.,.. .PITCH DISTRIBUTION .

. . . .

5y Jean (3iLnan,Jr; “.-.

..

. . . .sulqMRY ..

‘,

~ investigation was conducted at low Mach numbers ..to deterr~ine the effect of v~.riations in pitch distribu-tion on propel19v efficiency. i%-ee 1~-foot-diameterthree-blade tractcr propellers ~~ounted on a streamline”bcdy ware tested for a blade-angle range .fran150 to 650.

In addition. to the usual nrocadme of detennlnlngpropeller. thrust and po}iercoefficients by S’orce-balmcemeasurements, surveys were.nade of the total pressurein ths propeller walfe t~ determine th~ thrust loadlnssoThe over-all propeller characteristics as well as thethrust snd torque loadin.cjswere also dete.rqinedby anandyt?.cal ‘fi~th(kiq

.

The section t4rust and torque coefficients arepresented.for seven standard radii in a form that enablesrapid Ceteminatlon of the ‘&rust and torque loadings ofthe three propellers at operating conditions wilhln the .

ltilts of the data obtained. Charts are presented thatshow the var~ation of nowsr coefficient With blade-anglesetting and advance-diameter ratio and that include linesof’constan.t..efficiency”.Other charts show the variationaf thrust coefficient with advm~ce-diaineter tiatio at .both constant blade-angle setting and constant power coef-f’ictent. A cqmpcrison of the variat~~n df thrust coef-fiolent with advance-diameter ratio at sgveral constantvalues of power coefficient is made.to show the relativeeff$cie.ncy of tW three propellers for a large range ofoperating oondltions. The efficiencies ane compared atseveral .simtilatedfli~ht .cmditlons r~lng frcnntake-off t? high speed.

.,k..

.

1

.: ””.

2 ltACAARR “tiO . L6E22.... ..

For the”simulated fllgh% o.on~~ttons, the inducedaxial and rotational components of the eftlciency loss, “and the component due td prof~le drag are evaluated andpresented in tabular form. Representative distributions .:.of these induced and m?ofile-drag losses are shown.

Wod agreement was obtained between the calculatedand measured propeller characteristics. The rgsultsindicated that high efflci~ncl~a at large advance-c?iameter ratios (:n excess of 3.0) could be main~a:lnedif the Fitch distribution were near optim~m. The inducedaxial-energy loss was shown to be independent of pitchdistribution when the propellar was operating near peakefficiency, The induced rotational-energy loss might‘oecome excessively high at lar~e advance-diameter ratiosoThe Iosq of efficiency due to profile drag would becritically dependent on the advm;ce-diameter ratio and

,

the rel.,titinshiybetw~e~ Wlu t.in”yGL , at a given sectlmm

IK’150D7XTION

The 5.dealpitch distribution of a propeller is thepitch distribution that, for a given operating condition,will yield minimum energy losses- The induced energyl-egg.j.s a ininimu~ when the blade lcad~.ng is optim~;The profila-d.ra~ enerey 10SS is a minimum when the pro-duct of’the blade chord and profile-drag c0effici8nt ateach section is the least nossil?lefor the required bladeloadirlg. Thesa requirements for ninlmmm energy lossesmay se achteved for a given opgre.tiw condition byfollowing design ~rocedures such as those set forth inrefer:.nces 1 to 5; w.hlchare based on the work of Betzand Goldstein.

*cause of’the fixed pitch distribution of a givenpropeller, the proper load distribution can not bemalntainad over a range of operating. conditions. Thevariation from optinmn loadlng mciybecome appreciablefor large rang4s 02 operating contibions such as those “now being encountered b; high-speed airplanes, Z’heworkof reference 2 shows fihatimproperly loadin~ the pro-pellsr leads to appreciable increases ‘in Induced energylosses at hi~~ advaace-dt~m~ter ratios,.although theeffect is small “at.advance-diaiieter ratios less thanapproximately i?.5@ In particular, b% induced rotational-energy loss is shown to become excessive lf~thg shanksections at hi~h advaiice-diameter ratios are overloaded.

.

‘Thepresent investigation.wad nuide ~nthe Langley “propeller-research tunnel to determine the effacts ofpitch -dlstributton ~n. pro.paller c~agte.ristios for ara~e of’blade-angle settings trom 15° to 650.. The “program included tests at low Mach ntiers of threel@-f’obt-diameter propellers having ITACA-16-series see- ‘tldns and var~ng on~y in @toh distribution, In thisprogram the usual force-balance test methods were” “supplemented with wake surveys to detemlne the thrustloadings. The thrust and tor~~e loadings and propellercharacteristics were also detemnlned by an analyticalmethod with kwo-dimensional-airfoil .flata.

In the pr~sent paper the calculated &d measiu?edpre.pellsr”characteristios ard ocmparei! and curves areprssentmd that show the comparative efficiencies cf tiethrea z+ropellers for a large i~an~9of’operating condi-tions. Th~ calculated seotion thrust and torque coef-ficients were employed to evaluate tho induced axial- .ener~~ and rotational=ener~y lo~ses mti the lnss due toprofile drag for several operabing condltiens.

i’heseetlon thrust ant?.torqus coefficients are pre-sent~fiin a fomn that enables quick determination of thethrust and torque loadings of ths..three.propellers atoperattilgconditions within the llM.ts of the dataobtained.

A chart is presented that narmtts a felrly rapidqualitative determlnat- nf t?m”blade loadl.ngtfiran~prc~eller. This chart was found to be quite useful as anaid In the analys.Ls”of the reaults”uf this investigation,

af rotational.jmflow “fac+~r-{fig..-l~.

B .nuzh.r-uf propeller bladas

b blade- eecti6n cho~d, f’eet

—..—

. . ..,.

4“ NACA .AmRRNo.,L~...

.“

section design li~t~c.oei%lcfent , “ “ .-CLD .-”. ~ . . . .... -

,’Cp - ..“ po+er coiffici?nt. :~P~pn3D5 )”~ .4“ - - -

.

Ca ,...torque coefficient ~(m~/pn2D5) .....CT”” “ “ thrust coefficient (WPri@) . “

D.”. ~propeller diameter, feet . . . ..“.

AD change in body drag due to propeller slip-str~&M, D_dS

dD ‘“()

CDp;~b dr . ““section profiie”drag, :~ouzlds

(fisJ.1) . 2 ,.

dC.#ik .:. .sbcti.on torque coe~; lcidnt()

W& “.. .. . PV2D5 .

Er

AH

h

sect~on torque

section thrust

energy lost tofoos-pounds

f’o~~e , pounds (figo 1) “

~orce, pounds (fi~. 1) “

axial momentlm in propelier wake,per second

energ~ ‘.ost thrcugh profile drag, foot-poundsper second

energy lost tc,rotatiorml mmentum in pro-, peller wake, foot-pounds .=r second

.,~O~dSte~L~ correction factor for finite number

of blades

total-pressure rise in propeller wake, poundsper square foot

maximum thickness of blade section, feet. .

NACA.A=R NO. L6E22.I“ 5 ‘m-..“I. .:o. . .

J“ :admvanoe.-dlamatar ~at$o ,(-~/nD) . ,. “ - . -,...” ,. .

n“. -“propeller ~atii’&al- qpped, ~revoluti~s per . :.-second .... : “..:-l

. . . . . . . . . ..P power absorbed b “pro,pdller,;f’oot-poundsper

secoti .(2TmQ7 . -. ‘ ..,. . .

Q torqua OF propeller, foot-pounds ~“.

free-stream dynamic pressure ,“pounds”per:square foot (pv2/2 ) ,. ..

I R ● tiadfias”‘topropeller tin, fe.e.t v.,.1

r radius to propeller element.,feet

~ .shaft tension, pounds

T= pl’opulsiv~ thrust, pcnuxls (T - AD).

v- $rea-stream velocity, feet ~persecond. .

Vz ..local axial velocity, r)ro~e~hr removed; feetper SeCOild ..

71 . true resultant velocity, feet,per second (i’ig.1)

:Jwr

o“ gecmatrlc resultant velocity, feet per second(fig. 1),.

WI total Interference .viloiity at airfoil, feetper seoond (fi+ 1) .

x radius ratio “ (rfi). .

‘o “..’“radius ratio at spinmr juncture

a..

P

a Y= tan-l

seetio~ angle of attack, degrees (fiB. 1) .

blade- seotion angle, degrees (fig. 1)CD

(““1 CCLangle of inflow, degrees tan

(fig. 1) . )-@ sin $

,

I

I?AGAARB Mom L6E22”

propulsive effhhnO$ (TPV/p Or CTJ/Cp)

blade-se”ctlon profue-&g efficiency

mass density of air, slug per cubic foot

standard sea-level mass density, slug per cubicfoot.

section solidity (Bb/2Tfr)

aerodynamic hellx angle, degrees{;; l)j

geometric helix angle, degrees(r:g. 1)

angle of twist In propeller slipstream, degrees

13GjUATIONSMD METHOiJS (Xl?ANALYSIS

For the determination of section thrust coeffi-cient dCT/&Z from the wake pressure ~asurer.ents, a

convenient equation is given in reference ~ thattransposes to

dCT=

z“.

section thrust and torque

AH m #x(1)

qkcoefficients were calculated by

the method given in reference 5. The alrfoll character~tlcsshown in figure 2 for NACA 16-series nropeller sectjonswere ussd in the calculations. Tnese airfoil data wereinterpolated from reference 6. The free-stream velocitydistribution was assumed to be uniform and the calculationswere based on the ~ropeller destgn dimensions.

Equations for evaluating the induced fractional9nergy losses were talcm from ‘reference 2. The frac-tional energy lost to axial momentum is

(2)

NACA AEWiNC. L6z22 “

and to rotational momentum ... - .. .. .

“where

The value

all thl’9e

. . . . .--- ----

f

Er ‘~”=- “lsO” ‘ ‘dc~”” --”—=— al —&P CQ &c

X()

2

.,

7

. ... .. . ----- -

(3)

. . ..

(5)

of Xo for

wonellers.

this investigation IS 0.236 for

Tke fractional 9nergy loss due to profile drag Is

%1 J1.0

—=—P CQ

X()

-Thevalue of q? can beo

where

T’. =

tan $=

(, - .l.) Y?&x

shown to be

tsn $.

tan (p+ y)

+, tan kfo1

(6)

The angle y can be determined from figure 2(b) If theoperating Cn is known. An expression giving the ,operating .C~ oan be derived

. .

dCT ‘= *F (1 + a)2

z 8R ain2$ (CL

from the following: “... .

..

C(M $ - )CD&!in@ .-..

9 NACA ARR -No● L6Z.

. . . .

dCQ = ITOJ2X (1 + a)2—— (CL sin @ + CD Cos $ . .dx 16R . sin2@ .

El~.Y.Iinating CD from the ex.g@essions for.-t.hesectionthrust and torque and solving for CL .gives thefollowing equation .

( .)E$CL=4L x9+2tijfa-”9 sin2

xBbJ2 dx dx (1 + a)2

AnPARATUS

Test ~~uipment

The tests wkre ooudu2t6d Iii”the Lkn~ley propeller-research tunnel. A phOtO#’&lFh of the test setup isgiven as i’igurs ~ ur,dthe dime~islonal.details are shownin f1:.:ure!~. A close-up of We propeller-spinnerarra.m;e.neilt1s givsn as figure 5. me gap between thepropeller blade and the celluloid coverplate wasone lM.rt.y-s9 cond of’an inch all arcund .“

‘The:s~ropellers‘weredriven by two variable-speed25-horsepower electrlc inductlou motors that Incorpora-tedsprl~-sclsyn dynamometer equipment for measuring torque.Propollsr rotational speed was determined by means nfelectrlc tachometers and propeller thrust, by the tunnelthrust-balance equi-ment.

T~.etotal-pine.9surerise in the propeller wake wasdeterm%n~d by a“horizontal Palm of total-pressure tubesal@n2 thO right-had Vadius. The radial stations atwhich the individual total-prassure tubes were locatedwere at jo, 5L, 57, ES L5S 51S ~zS 60e5~ 65s 75# ~0~85P !30?%s ?9, 103, arfi110 pe~;cent of’the propellerradius. The distance frmn the propeller center line

back to the total-pressure tubes was 7* inches (0.0625D),

and the minimum clearance betwsen the blade trailingedge and th9 total-pres.lure tube at 0.30R was 0.0135D, .or 1.62 inches. Pressures were recorded photographically

.from an XA5A recording multlple tube manometer, whichwas inclined 60° from the vertical in order to doublethe magnitude of’the readings.

.

!.D ,.I\r. .

.,. .

~

NACA ARR NO. L61E2

. .

-PROPELLERS.... . -,, \ !-. “.l. ~, ----

-Thethree .nronellem selected

.

9

.. . .

. .,. ---- -+, --—-.

for the”lnvesti~a-tl.oh #ere +Ae N~-CA’10-308-03-55, 10-308-03-45, and-1O*3O3-O3-5O and wjll hereinafter.be referred to as.propellers 55S, ~5S, and 3(3S,respsotively. The firstgroup of nmmerala in the designation denotes the prd=peller diameter in feet; the first digit of the secondgroup Is ten times the design Ilft coefficient at 0.70R;ar.dthe last two digits of the secd:z~group expressthe thickness-chord d?atlo at 0.70R. l%e third group offigures gives the solidity per blade at 0.70R and thelast group designates the approx’imatioblade-angle settingat 0.705 for the design condition. The blade designincorporates NACA 16-series sections. f The activityfactor for each blade is 9(Ior for tilethree->lade tractorpropellers, 270. The blade-tom characteristics areshown in fi~;ure6, whf.ch also’includes a curve showingthe design lift coefficient C~l of ths airfo%l section

at each station. The angular t~ist (!+- .PO.?qR’) of .the blades is compared In Fisunare shown h figure-7(b).

The hlaciss of propeller ~5Sdural and conformed very closelyTb blades of propellers 55S wad

7(a) ‘and “curv=s“ of p/h

were constructed ofto the design dimensions.30S were constructed

of mahogany and varic$dso~ewhat from the designdimens~ons. The blade-section angles of propeller 55Swere Generally within *0.25° of the specified angles,but two of the blades of propeller 3(ISwere found to beas muoh as 2° too Mgh in the tip region and to varyby *l” In the shank sections.

TESTS

The fiangeof thethrust tb well beyondthe following table:

..

foroe measurements was from zeno”the stall For the blade angles of .

‘L, ._

I.

10 NACA ARR NQm L6E22

PropellerI

Blade~ %:;’ 0”75’

55s 15 25 30 55 40 ~5 50 55 60

45s , 15 25 30 35 40 45 50 55 “-

30s 15 25 30 35 -- 4.5 -- 55 -“

--

65

65

The-engine speed varied from a mtiimm of 550 rpm forlow blade angles to 175 rpm for peak efficiency at

The turcnelairspeed varied from 90 milesP0075J3= 65°- , .

per hour for the large blade. sngles to 37.5 miles perhour for ?eak efficiency at ~3.71jR= 15°. The Reynoldsnll,~-~>r“DaSSClon the cl=.orda~ 0.75fiwas of the order .of 1 x 106. The resultant ~lo~ities were too low tolead to any comnn?essibilit~ o~i’ecbsfor the tip Machnum~er was always less than E,3.

At each blade angle, measurements of the total pres-sure were made for a r~e of.advancq-diaiieter ratio toinclude”only the region of’peak efficiency. “No attemptwas made to obtain measurements under conditions of’stalled operation because previous investigations (forexample, reference b) have shown t~.atsuch measurementsare unreliable. The pressure mess-arements were not*extended to include zero thrust bscause of the limitedtime available for ~estlng. A velocity survey (propeller

removed) was made 7$ inches behind the propeller disk

and tileresults are shown in fifyxre8.

Blade-deflection tests cf bhe thin wooden blades, inwhich a reflected-light-beam icethotlsimilar to that ofreference ~ was ussd, showed that the blade deflectionswere not ul~duly large. At a blade angle of 30° thedeflection varied from about C.1° at an advance-diameterof O*3 to no measlmable mount at peak efficiency. Ata blade angle of 55°, the de~lectlon varied from 0.6°at a low value of J to O.1° at peak efficiency.

RESULTS A1>~DISCUSSION

In presentin~ the results of this investigation ofpitch distribution, the blade saction clw?actarl.sties

‘[ ., ../ NACA.ARR NC =L6E2-2 ~ 11. “,.

L

. . .,. .“...and propeller characteristics are dlsous.s.e.d”s@ar&tel~.The efficd.enci.esof the three propel19rs’,are comparsd “

\-’ for a,range of.operating.,oondltlons‘“to,sh~w .tho effect”-;”~..

of changes in the load distribution.}. .A dlspussion “of ,-

)energy losses cbmplete”s the presentat$ona

, .. .1 .‘? . .

Blade Section .Characterist’lcs ....,,,, . . :.

Cql.culatedblade -s60tion clzaracteristlcs.- The cal” ,.oulated blade section characteristics for 9even standard ““radii arb shown In figures 9 to ~. The vtiri.atton “aOf dCT,/dX wtth J at both constiintblade-sngle setting .and constant rower coefficient tor propellers 55S, ~5$, “and 30S, are shown In figures 9 to 11. The corresponc?l~val’ms of dc@x are shown in figures 12 to I-4..

?Ieasuredblade=sectio”n charactei’istics.- Curvesof’ d-: a:~ainst J,” ~L~‘%~”:~’hir~sdfi~om the Wa’W ~res-sure measurements, are V1’f3Sf.:iltHJ. h fi.,uros~ to 11 forsevs.ralblade-an~le ~ettin~s~ Close agresnent betweenthe meaaured C@ calculated results was not vealized.Some ,of the factors that may hsve a~factsd tlieresultsare: the flow angularity and veloclty variation in the “tunnel $et, tJheincrease in stream velocity at theSpinrler!(fig, 5), the use @ interpolated airfoll-section data, and the previously noted variatton of the.wooden bladss from design di.??enslons~ Some error wasalso probably derived from the use of a ai

3le survey

rako for a recsnt investigation (reference .) concludesthat mope accurate data result from wake mrve~s Qcrossthe propeller diameter rather than along a si~le radius.

dCTThe “measured ~curyes, however, are gentirally

dxparallel to the calculated curves. Inasmuch as”theassumption of tha “independence“of’blade sectitinsholdsto a fal~ Hegree of scouracy, ‘themeasurad and calcu- ‘lated ourves”of- dCT/dx cbuld possibly be brought into .substantla”l agreement by consi~,~rirq$only tlM blade

discrepancies and.the actual ~distrlbut$on. This

. procedl~rewas not a~tempted, however, because of the -unoerta~nty introduced by the use & a single survey ~rake.

3ecause of the unsatisfactory nature of the measuredsection thrust co”af~lci.ents,the discussion 2s confinedmainly to the calculated section characteristics.

.

1“::.,........ ““’”.phopellerCM~ac@r18tt@s s., “i. . . .,...*. ... . . .’.’ ~,;+ . .“ . .... . . .:.,

-The ,over-all.cM-acteristlcS. of propellers 55S, .45S, and 30S; %isdetermined ~from ‘Po.kos.liests,‘are“Sb.OVM”h fi.gures15 to 17,’re”specttre17.=.~These.figures..““.show the varlatton of .0

%.wlth .J.” ab op~stant blade- .. .

angle settings and Inclu e contour lines of const.mt . .eff’ialenoy. The operating ohart ‘for propeller “55S. .(fig; 1~ ) is al?special interest because .It,SWOWS :thathigh et’flo~ency can be obtained if the pitch dfstrlhu- “tion is,nea.rthe optimum at lsxge advance=d~ame”ter.’ “rdtios:.#The region of peak efficiencyocpprs at loweradvance-diameter ratios for propellers.b5S and.30S .’.: .(rigs. 16 W@ 17) than for propeiler 55S. .The adva?ce- .diameter ratio for peak efficiency varies with. the”” “ ‘ .design pitch distribution and, 01’fuhther interest:’ ‘the region of high efficiencies becomes more limited;- “ ‘as the .deafign.pitchdlstribation is reduced. . The,csmtou.curve .of propeller 55S f’orgl-~oercent efficiency, ~forexample, extends over a rarn~eof J from 1.8 to. ‘“:j’~about 4..0Whereas the correspondln~ range for pFo= ‘:”..peller &5S .isfrom app~oximately 1..$!to ~.O and’tliat .for propeller 303, from approximately 1.1 to 2.1. “

.. .T“he’variation “of the thrust coefficients with

advance-di~meter ratio at constant blade-angle settingsand.a~qo a.tconstant.power coefficients iS shown $n.f~gures 18 to 20 ~or propellers 55s, 45s, and 30S, . . . ..!re.spe.ctivelyo.The var~.ationof CT with J at. - . ,constant CPS shown “for all thbee propellers infi~tie-21$”-arovid6k a comparison of their relative merits ~for a large range of operating conditions...- ....

I.. . . . . ... . . .

~ Cornpaniqon’of experimental and.calculated propeller,characteristics.- The calculated

~

thrust and power c’oef--c en s are s own as “s~ort.-dash”linesI’nfigures Is “. . ‘

to ,Q.;f,oq.com~ison ,wlth Ehe measured values. The “t ,

F

our ~s at equal :blade-~le setti~s shqw a varying. , .lac @f agreement, principally as a result of the “pre~ioual.y”no$-ed.bladedi”screydnoies tithe “nonunifom-.velboitiy.f’leld.,. TV~-.calcu2ated.”r0sults.for.the ~ta~-.-.-.-:propeller (&5S) are seen to be in better agreementwith tb@.me@ired Vs.ults.tw” arqs~e.cialc.uldted ... “resi~.ltsfor~the wooden uropellqr4,’.Wliichindicates Mat ~“the blad6~design dlscrgpancies are ‘the more importantcause of dls,agreement‘In the results of the -twomethods.=When the dalculatied thrust oodfflclents are. ccmparedwith the experimental values at the same .~owsrcoefficient

! ..

I

(figs. la to 20), tmod”w-ment fS obt~~~ed betwe~fithe two sets of data -throughmost of the operating range.

The good agreement between the experimental ahd - “oalculatied”values of thrust coefficient at a given powercoefficient indicates that reasonably accurate bladethrust-loadlng and torque-loadhg curves may beconstruct’ld from ths calculated sect:-onthrust and “torque coeffloients shown in flSuras 9 to IL. A crxn-parlscn of mea$ured and calculated thrust-loadh.g curvesat constant power coefficient is given in fi~ure 22.Eeccluse0? the -@certainty of the wake-survey data, “this ccllipar~sciliS a~J~roXhhteJ but the comparison isbeltevad to tmd to bear m.:tthe assumption that the ~calculated loadings”will he similar to the actuall.oadlngfor a given operating corklition.

r— Prone~.lcr1:-5S

~—-– ‘-—---

Blade angle at 0.75R

Comparison of p~’ope?ler e.ffictsncies at v~riouasimulated illj-j:tCOrACltlmm ● - S9veral val~~es of Jand

c?were chosejl-ti~csis for comparison of the

propel er c-haracteristlcs and ~or malysis of theefficiency losses. Tor constant-speed propellers,

.

~ ,:...: . . . . . . . . . . . . . . . .,.

c?increase a qvfth,lncre”aai~:“aL~ltiide@rid. J ..increasesw.th .i.r.creaqtngforward. speed. “~alues .& ,..Cp.and J+.-s> wsre “~&~re”~dhe”.”-seldqted to Mm@te ‘&.ow‘bPeed at-ssa “ .:.

,. lev~l,.tid~um And high dpeeds “at d mediqmm al.tltms, ~ .1’ and high speeds at’two high alti@dea ~. -Zhese valtie.qF“”“’ .

of ,~~ .Gnd J &nd other be~timent data are preqen~~a.~, .;.&n the .fo.l.lowi.x@tiable: ““ . “ .“ “ ., . ;: ....“....

T$.-&f Cltib “atBIGh BHigh .:.::.-.“. High

Fli&ht-“’.33;:00

speed at “a”eed at speetl..ak.“ ..”condition level F53$:00. “ A;:oq . 5?i#o ~.:”..

.

P/Po 1,000 0,325”, 0.325 0 200. . 0,250.

J .80 2.00 5.15 j.oo 3.80

CP .080 .246 ‘16,q. .1+00, .320.

“It is ernnha~tzg”dthat compressibility effects are .“”“not considered in this invosEiHatlon. In prqc.tj.cbthesimulated oper~ting conditicna .consldered, except .possibly take~off, would p’robahlylead to cti~.presstbi.~i.tylosse~ that would exceed the other losses dl.scussedherein.

The valu3s from tb~ preceding table of J = ~ ~15and c

f= 0.21+6correspond to the.hi~est efficiency of

pro~l &r 55S on the effisienc~~ contour curve. (Geefig, 15. ) If these valu9s are asstie.d to repvessn$ high .speed at altitude, maximum” rate of’climb at the samealtitude would .requlre the.same value of CF but would” ““.require ~n .ad.vance-diameterratio of the order hf 1-2 .to 2.0”;depe-rid@g on the airplane characteristics. In.. .:this corn~arlson, cI@b 1s represented by J = 2iOC)

0.246 ,“ Take-off is usually accanpl.ished at . ‘ ~.and Cp=.

m advantie-dlarpeter.ratlo of 0,5 or,less, but. in thiscase a valqo of .:J= 0.80 and a value of Cp of.O.08Q .“ “are asaumed. HecAuse of the.current lack d’ data on “ “HACA 16-senies.airfoils at the lerger lift coof~icj.ents,It j.snot possible to calculate the values of. ‘P justmenttcned for advance-di~eter ratios iowar than thoseused herelrl for climb sndltake-off...

Ilmlnn I

16

1

I

The variation of rj at the mlecte.d values of Cp

is shown in figure 25 for a ba~e Or J to include thevalues of’ J“ chosen for comparison. Propeller”5 S is :seen to have a higher efficiency than propellers z

J ~imulating c~mband 3~S”i.n bhe range of advance~dlameter ratio from 2.60to 3,+30 In most of the range “of’St altituds (1.2 to 2.G] propelle~ ~~S is most efflclent;whereas propeller 50S Is -mostei’’ftcientin bake-off, Thedifference in”efficimcy in climb aad take-off, howevar,Is Sw!ll. “The values of q at the sirmlated fl$ghtconditions ars summa.rlzed in.table I?

.“

.m.

. ..“

Ef?scti on Load Xstrihution of’Changes

.

The

~n Operating Ccuxlitlons

thrust.loadlng @ tw-?ue.loadin.~ arves shownin’ffl.guraa~ to 23 ar6 .presfil~t~fltor the-simulated “flight cond~tions of ths nrecsding section. These fig-ures indicate that the differences in the loadings dueto the pitch-distribution differences of the three pro-pellers are greater at high than at ?.OWadvance-diameterratios f.crequql po~er a-bsorpti.on,

For a ~)ivanpropellar thg r~sultant force at anyblade seoticn, which determines Me tkwust and torqueat the section, depends on the square of the resultantvelocity ‘f;. and the geometric angla cf attadk p - $0*At constw.t advance-diameter ratio, blm resultant “velocities .lncreasewith :ncreasln~ radius. -Xith.increasin& advailce-diamctor ratio, the resultantvelocities of the inboard sections becme a largerporcantago Cf ;;heresultant velocities at the tip sec.tiOJLS . If~_@o remains constant alo.%stileblade,

for example, Inoreas:ng t?lsvalue of J increases theres-~-.ltarl”tforce ~f’the shank sJctj.onsas comnared tothat or th~ tlp sectlcnsa TW gooxetric an~le ofattack, however, is not necessar~ly cbnstunt along theblade ?Jlltdepends on [~ Ud $0 .t each section. Therafiialvariation or ~. at an;r J can be determinedfrom tka Telqtion

._—. - —

NACA ARR No. L6E22 17. . ... ......... ...- . . .. . . ..“.... .... . .. ...”“

The rud~al yariat~o~.oi’‘*-@Q:was-;a~c~l~ted”for”-a ‘larg6, range” @ advaiice--dianeter :PAtio, ‘with VL/V “.,-:-----.taken .tb‘be““equal-.to”1.0 &i’-along the blade. ” The”“.““- “varIation of go~ .expresbed aa $0 F $0 WIth J... m..-. . 0m75R’~ ---.” .--,at ei.~t “sta&lard radii IS shown.in figure 2g.- “!l!hesecurves.@ve .the an@lar twlst oflthe resultant geometrlcair stream for any vaZue of J,

The angular twist of the propeller blades .has “previously been expressed as p ~ ~o,75R” “ (Seefig. 7(a). ) If for sons value of J undev considera-tion the quantity $0 - $ Is subtracted frcm the”

OU.75R

. . ...-. .

“.

t’ “

quantity p - :0,75R, the difference gives a measure

of’ the variation b? the. geometric angles of attackThe c.~ir~esof . -

at..J .= 3.60 and for propellor 45Sshown In fl(.u~es50(a) and 30(b).

for ~ropeller ]+~Sat. J = 0.80 (fig. 30(~)) shows that theshank a?l~lesof’attach-are .muc.hlarger t-nmnare the tipangle: of attack. ;~l~~t~f’t~h~th~:~stand torque -load of .propeller ~+.5SIs shown in figure 2& to be looate.dat theout:mard statlohs “in s~ite of the large shan”kmugles,the reman being th’itat J = O,&? the resultantvelocities ovs~ the shank secticqs are.very low apcm.mared with the resultant velboities over the tipseotions. The variation of the sqiiareof the i-atibof-the shank resliltmt velgcl.ty @ the tip reau.ltant velocitywith advance-dlamater ratio is i~.luqtrateclby thefollowiq table: ‘ “

.*

18 NACA AFR NO ● L6E22

.,

J“ 0.5 1.0 1.5 2.0 2.5 3.0 4.0 5.0 “

2

c J .

‘*030Ro.1~ 0.191 0.280 3.376 o..l@l0.5M O● 675 0.765

~w.9. . .

The res~~.ltantforce at a section (when .nrof’iledrag is “bC~lf2 dr

neglected) is —. Inasmuch as the magnitude2

of’ Ehe vector ‘{Y is very nearly tinesame as that ofvector T!., the table”,just given indicates directly theIncreasing importance of a shank section as comparedwith a tip section as J 1s inoreased.

If values of p - ‘0.75R for any propeller are

.

ma~ bs readily seen. The plot therefore gives q quall-tativa renresentatinn of the angle-of-attack variation,which, with due consideration to the radial Iocatlon ofChe sections, the section chords, and the value of J,gives a rough idea of the load@ to he expected. Forpropellers incorporating sections ‘with large values ofangle of zero lift, it may be desirable to base thaangle ~ on the zero-lift line rather than on thechord line of the section..

The blade twist P“ ~&75R .ofa structurally

practical propeller should be’~pproximately the sameas the twist of th~ resultant air strea~~to realizethe best efficiency at a given J. i?opexample, thea~gular blade twist of propellers 55S, L5S, and 50Sis Lndicated in figure 29 at J = j.15, 2.60, a-rid1.4o,respectively; for each nropeller the value cf Jcorresponds approximately to teak e.f?iciency. In eachcase tne blade twist apnroxl.mtitesthe air-stream twistat the value of J fm.peak efficiency. Deviationsfrom she optlnum blade twist .Ieadto more tiportantlosses at high than at low values of J as illustratedby the ~j-values in table I. At J= 0T60, for example,

.

.- .—

NACA A.RRNo ● “L6E22 ““ 19

. .

tha “difference In q :for.propeSler~ ~5S and 30S.. “ “is 0,055; at J--=3.30,.the .dlf’i?@rqnce~n q for ~ro- .,,.~m~.h?rS. 30S W 55s”-’t#ro.083-,-,- :-.- .

...Tl& most interesting @qt %=ought out In figure 29

is that in order to cohform to the r~swlban t.twistimthedesign.blade twist should be Imreised.as-the des~gn JIs increase~ to a value.of about 2.0 and should thenbedecrq+sed as J is $%rther lncYeased. If the propellerdesign J I@.about 2.0, the Dlade twist fails to con.form.to the twist of the.resultant air”stream at vdluesof .U “either higher or lotierthan 2,0, If the vtllua” Of

the design Jblade twist.lsto operhteat

..

is 3.0 cm greater, on the other hand, theslmllar to that of a propeller designe~ . ~J = 1.0.

3reak~own of.Fhmr:y Losses

the ftve simulated flight concli”cions,mxl ~he.results ‘are shown in table 1. .The sum oi’ ~~L$3S9 1039e8

IIa + ~r + ~D

is nr~sented fcr ca:pariaon with the .u

mess-~i’;d.tbtal fractional energ;.-10ss 1 - Tj, “in which ~~~.~.valueof q is tke observed value. Inasar~chas,

‘a +E+-~f’orinto.rpressible flow, the value

P.,

rev:’esents”-lh total fractional eriergy 10ss, “the”valuesm + .araa + ED

C?fP“

and 1 - 7; in table I should be very

nearly equal. The calculated t’rqctional energy losses . .closely check the measured.losses In several instances,but inequalities oocur bscause of tip discrepanciesbetween hhe actual and calculated loadings, as indi-cated in fl~ure 22X anG also because the agreementbetween c“alculate.dand neasur~d thrust coefficients atequal ~ClR3i’ oceff’1.cientsis not exact in all cases. Thelaclccd’aCreemer~$at equal powe~ coef’f’icientsi.sillustnatd‘uy a comparison ‘in table I,of the.integrated CP-values. .from figura$ 2)+”td2~ with the Cp-valqes chose; for the

simulated fli~ht.condjtlons and by a comparison of the .observed q.ndcalculated thrust coeSffctents. Theintegrated value of for propeller 30S, for exampleJ~P ... . .

-. .

. .

—- — —- .— .-*

—-1

20

is j psrcent

WA ARR ?h L6E22..

less than the Cp-value chosen for simulated .

fllght at J a 3.15? and the Integrated CT~val~e is~ percent higher than the observed. ~ at J = 2..00.

● Ea “: &cial-enerfiy Io”ss.-The ~values for the three “

propellers “in table. I are of the same magnitude at anyone o.parating condition. ~ne axial-energy loss is alarge geroeatage of the total energ~ loss at J = 0.80,but this percentage dec~eases as J increases,

.Yknresentative distributions of the axial-momentur~-. dCT

Ic)asf’tictoti~— Are shown :.n$lgu~es 31(a) and 32b)dx.

for climb and for one of Me high-~peed conditions. TheM.stributions fos the o~her high-speed conditions arestiilar to ~igure 32(a) and for take-off, compare withthose f.~rclimb (fig. 31(a)). .

Tle calculated axial-en~rEy losses for each simulatedflight cmdition, are compared in tabla II with theoptimum axial-energy losses as determined from refer-ence 2 for the same fli&~t condltlon, The optimum and~a~culated losses practicall;rcoincide for each flightcondition, which shows that .l?-ttle,if any,improvementIn the sxial-energ~ loss could be achieved by further. .v~i’yi~~ the load dtstrihution of these three propellers.

Rotational-energy loss,- T~ ~~stributions of thg—. .. .. . d~n “

ro:latio~.al-energy-lossFactor a’d are shown in fig-dx.

ur’ns~l(b) and 32(b) for climb and high speed, Thediatrit’.~tionfor take-off’is similar to..cllmband all .hi~h-a.wsc~ d~stributions are col~p~brableto that offi~~uw 32(5!. The integrated results In ta-oleII showthut the roational-energy loss g9nerally tenfistoincrease with increasing J. Because of the heaviershank J.cxdln”;sof propellers ~5S and 30S, the rota-t~onal losses oi these “propellers &re,gre&ter than thoseof ~rop=~.ier 55S.

A c“onqmrison of the calculated and opthqum valuesof Er/P in table II indicatissthat the rotattonal~energy loss of Propeller 55S is about optimum throughoutthe operating ra~e under consideration but that gainsin efficiency coL~Zdbe realized in the case of pro- “pellers !;.5S:and3gS at large val:l.esof J.

. ..

.... .

.- -.. .

IWCA “~ lb:.Ii&22 .-.. 21” “

that

Xtanjzf=

as discussed in re~erence 3.dition, th:siunif’ormhelkcal

. .

constant

For.a ~mtven operating con-Wake is attained by a

ce~tain distrlbutim of’t~leblade loadlng bCL. - Chm-tsin references 1 ~nd 3 that give tl~enecessary dlstribu.-tion d’ bCL to attal’nminimum indhced energy lossesat a given operati~ng.condition ‘show that . bCL nlustbe decreased in tha shank region as- J ‘is Inc-beased. . .

al~ is thus kept as small”a~ practipahb..

The factor

in the region wherq large values of ~ age unavoidable,

,. ... . ..

I

22 :.~ACA .ARR NO.=L6E22

.

“ Figurc3 29, howe.ver, shows that a propeller designedta operate at an adv@nce~difitbr da}f~ of io~~~y”l.Oto 2.o (for .example, prowlla~s 3~S.~d 45s) may beoverloaded along the Inner.radii If It is operated at”values Of “ J in exoess of about 2.5. At J :.3.15 .

the Inboard values of al% for.propellers 45S

and 30S are shown in figure 32(b) to be much largerthan those ?or propeller 55S, Beoause of’a slmllaroverloading of’the shank sections at - J = 3.80, theresults in table I give values of’.E /P: for.pro-pellers 45S and 30S that are nearly ~ouble the losstn rotational energy for propslldr 55S.

“Propeller wei~ht and diameter lfi.itatlons generallyrequird heavier loadings than tiioseencountered with thepropellers “tested. Charts in reference 2 show that fora given nwnber.of blades the-o~timum value of ~/Pbecomes larger if the loading is increased at a oon-starit J. Hence, for nor~ lmavily loaded propellers,nonopt’imum load dis~r+k,utions of the type experienced by.propellers 30S and l~5S lead to rotational-energy los~esmore serious than the results of’table I indicate.

‘_M.eprofile-drag energy loss varies with CD/CL

as indto~ted by the equation

For a small oonstant value of c#~, the value of Tl~

does not change appreciably in the approximate range “of ~ from 20° to 70°. The value of ?jfo decreasesrapidly as the value of @ decreases below about 20°or increases above about 70°.

The value of CD/CL, or “tany, varies with CL

as shcwn in figure 2(b). Very low oPOrati~ C#L-values

~d CL-val-Ugsbeyond the stall produce an abruptincrease in t~ Y with a corresponding increase in theproi’ile-drag loss,

The profile-drag losses for the five simulated flightconditions discussed herein are of particular interest.

,

NACA ~ r?:,L6E22 I . . . 23

In tqke-pff,.for exa~ple, the measured e$.fi.olencyof.nropellsr ~!5Sis 31.5 percent”as com ared with

&!35.O .pero.entfor..pr@elle&.3OS and. ,.1 percent “forpropeller ~~S. OpeTati~ CL-val~es.Were determinedfor take-off and are.presented in fig= 38.. ~ CG-valuas of prop~ller 45S, nearly Oo~, in the”’rOglon .of 0.503, ape on the borde~ of the re”glonRor an abru~t:rlae of tan y. (See fig, 2(b))o Because the airfoilsection characteristics are interpolated, however, thevalues of CL ti t-y show~lmust be regarded asestimates rathe”rthan.the actual valuea at the b~ademEenc~,.although. the calculated vaue of . E&P ..forpropeller 45S for take-ofi’ cnly sl<Shtly.exceeds thevalue for either of the other two propellers, inactuallty the profile-cirag loss could be larger than . .shown - or large enougl~ to acconnt for the d+acrepancy”

~+~r+%between the value O.1~1 forP

ad 0.185

.

%.

for 1.- q, in table I, If tihis.sun:~ositton is tenable,the t&e-off qu~li~ies of propeiler 1~.5ticould “be improvedelthe~’b“yreduciw tilepitch In +jhe.raqlonc)f 0.5R orby lncor~orating 8h&k sections ~viti~a-hl~}lor critical “lift coefficient.

?he g~od.efficiency of propeller 55S In take-off,~~..l~rcent as ccmmred ]~lth 35”perccmt for pro-peller 50S, illustrates a wevio-asly mentioned point -the sti.il~zityof the pitch i!istrfbution of a propellerof hi,.&pi Lch (J = ~.0 OP greater) to that of a pro-peller of low pitch. (See fig. 29.) ,

Yh: distribution of fractional energy.los.,sdue toprofile dr~g of nro.peller~OS in climb (fj.g~34) .ah~m . ‘

bhat t~is.loss is.large in the tip region. By call- .paring $Q figure 29 the blade twist at the.tip(beyond 0.75R] with the restitant a$r-stream twist,

“..

propeller 30S 1s readily @een to be insufficientlytwisted fn thts region for J = 2.00, :AS a result,~&l~6~ Of CL ~me ‘hityhin the tip region.. m-a Osti- “

mated CL-values of all three ~ropf311’e.rsare shswn in

figure 59..

The distributions of fractional efiergy-loss due toprofila drag (figs. 35 to 57) gre sinl.larSOT all three .of the almulated high-speed flight conditions. The .estlmat6d CL-val~es Of.~e threG prOpdllOdS at “ “. ...:

. .

M

(

,.

. . .

. .

.

.

. .

. , .m.

J“= 3.15 and Cp = 0.246 are shown in f@@e .40. It ~

will be noted that the CL-.val~~. ‘a~thb i~r radii of. .%propeller 55S are very low and @noe lead to.large ‘values of tan y. l@e resulting.low profile-dragefftcienoy at the inner radii does not seriously affectthe propeller efficiency, however.,because of the smallco”ntributi.onof these sections-to the total power absorp-tion.

. .

: A comparison of the-rotational- and profilo-dragenergy-losses - at J = 3.80 shows that of the twolosse9 the profilq-drag loss is the more important foreach..nro”peller- Tlie CL-variations for this flight “

condition, presented in figure &l, indicate that theCL-va~u~s”@f” all three propellers ‘are in a favorable “C~CL range f-ormost of the propellar radius. The”rolatioqshlp between CL alla tan y Qf the shank sec. .tions (fr~ x = 0.3 to x = 0.5) “ Is more favorablef’o,rpropellers 45S and-50S than fob propeller 55S. “ Thedrag losses are shown in fl~ure 37.to be higher for theshank sections in the case of.propeller 45S and 30Sthan for propeller 55S.

.Atx= ’003 and J = 3.80 the angle of the

resultant wind @ is very large. The angle PO is a

close approximation to the angle ~ near peak efficiency, .and “$0 at J = 3.80 is shown in figure 29 to be

about 76°, Hence, $-values in the region of O.~OR are -in the range in which only sliGht differences in $cause large df.fferences”In 71’0s even if tan y is the

salflef’orall three propellers. This sensitivity of theprofile-drag 10SS to large geometric helix angles,ceupled with the large power absorption of the innerradii, has a very detrimental effedt on the eff’iclencyof propellers 45S and 30S. Propeller 30S suffers”an “additional”profile-drag loss because of the low CLQv&lue

at 0,70R;”the “bump” in the curve of the profIle-drag-10SS distribut~on of propeller 30S (fig. 37) iS theresult o.fthe increased value of tan y. .

.

CONCLUS1ONS

Tests were made at low Mach numbers to determinethe effects of pitch distribution on propeller oharac-terlstics for a large range of operating conditions.

.

The three-blade tractor propell~rs used were of’11)-footdhmdter’aid-ernbodled lTACA”l&serles airfoil sections.The following conoluslons are based on the results of .“~ese tests sup~lepente~ with data otiliainedh~ an ‘ .analytlcal~method: ,.

.

1. Good agreement was obtatned between” the measurediand ctilculate~propeller charac.t.erlst.lcso.

2. “High effiolency “canbe obtai,bdd if tm”pltchdistribution is near the optimum at large advanoe-dlameter ratios, .

~. A propel=.er of design ad&nce-dismeter ratioof 300 or greater would have a favorable loadlng for ,lower values of”the advance-dlaneter i-~tioIn t?hetake-off’range (J = 1.0 or lorer).

~+.Variations in load distrttution have very little.effect on the magnitude of’the induced axial-energy loss.near:peak efficiency.

: 5, The use of a propeller at other than designadvance-diameter ratio might incur e.xcesslve rotatlonal-energy losses if the oprating advance-diameter ratio .is in excess of about 2.5;

Langley Memorial Aeronautical LaboratoryNational Advisory Committee for Aeronsuti.cs

Langley Field, Va.

.

.“ .. .

.,. -.— -..

.

.

26 FACA AI?R No. L&22 ‘

. . -EI?CXS “

1. Crigler, John L., and Talkin, Herbert’ W.: PropellerSelection from Aerodynamic Cons.kderaticns,NACA ACR, July 1* ●

2. Crigler, John.L., and Talkin, EarbaFt ;Y.: Chartsfor Deten.inln~ Propeller ~fic?.ency. NACA AaRNO. TL129, 1~~.

5. Hartman, Ed#in P., and I@Mman, Lewis: . AerodynamicProblems in the Design”of Efficient Propellers.NACA kCR, Aug. 19420

4. Stickle, George W., and Crigler, John L.: PropellerAnalysis from Experimental Datam NACA Rep.NO. 712, 1941.

5. Crigler,. John L.: Comparfson”of Calculated andExperimental propeller Characterlstlcs for Four-,

-, and Eight-Blade Sin.gle-Rotati~ Propellers.;tiA ACR ~fOo4B04, 1944-

7. Hartman, Edwin P., and Biermann, David: “TfieTorsionaland 3ending Def3.ection of Full-Scale Aluminum-Allov Propeller Blades under Normal OperatingConditions. NACA Rep, NO. 644, 1938.

8. Pendlay, Robert E.: ~$?fect of Propeller-Axis Angleof Attack on Thrust Distribution over the Pro-peller Disk In Relation to ??ake-Survey Measurementof Thrust. NACA A.RRNO, L5J02b , lgl+s.

..*

,-..!, -.. ‘!. -’~

.

TABLEI

. . . . +. .

Iq+q+q ‘.::; -.’ “.. “..“. ObservedRepeller - . ~. “~;P E/P @

1-

Calouiated0b8ervedklauiated’l- q..

P.. . .b. % ~ ,CT” “ ~! -.... A-:” —. -. ..—., T&e-off; ‘J,0080; Cp,:Oo(.)80,

. . . .,

..

5s.z

O.sl+l 0..P -

O:;$ O.;i. C15; 0.159. 0.0S6 o.Oak$l. . ;O.0B2“..5s ●615 .ol@ . .161 .,165. .080: .e0815 . .08f+ .30s - “ JYjo .108~ ,019 ‘.o117- ‘ :153- -.W. $ .;o.~ ~ .~m9850 ,“@ .

.: “IIi”ghSpied; J,’3:1$;.Cp,.ti,~ - “’ . “ ..!

.“

HighSpeed; ~, 3c60; Cp?0s320c “ :> ..

.. .m .....,.. . . .

0.%

. 00063. oh86. .

.J,:~!ila

o:315 . 0.07’70.0 . ‘8lx! ‘*W > .313 . ●

,070 .129: : .169. ; ~313. . .. .. . . .:... . . ,,. .. . . . . .

NATIONALADVISCRY .COMMITTEEFOR AERONAUTICS

1

28 TABLE .11 H#~A ARR No* L6E22

INDUCED EFFICIENCY LOSSES .OF...PROPELLERS55.% 45S, AND 30SAND ~PTIMRL ENERGY LOSSES FOR SEVERAt SItiTED

.tiIG~-C.O@ITmNS “ . ~. . . .,.. ..

Calculated opthum Calculated “ optinlumPro’peher . Es/P “ Es/P “ E@ Er/P

(a) (a)

35s O.::); . 0,033 . o.oj6 0 ● Q5745 s

?“.oj3 ..056 .037

3.0s . , @ .* 053 .037 .037.Cp = oJ2h-~; I“J-= 3~15 s “ “.,

T“

d5s o ● 012 0.04 ,0.026 , 0.0255s .009 : . o~ .“054 ● 02.5

30s “ “ .009 ● Oil+ ,054 ,025

Cp = 0,400; J = 5,00”

.l----&-

?5s 0 ● 018 “

7

0.043 99045~s.. ; “ .016 .018 . .051 ● 045

3~9 .. .018 , oli3 ,051 .04.5..

CP= 0.320; J = ~.so. .

. “5: :. o::m~, “.0::::“$5

0.029 0.029.050 . .029

“ 30s .006 , ~~-J ..053 .029

aOpttium values are from figures 2 and 3 of reference 2.

NATIONAL ADVISORYCOKMITTFZZ FOR AERONAUTICS

. .,.

. . . .-. . . .

NACA ARR No. L6E22

.-

Fig. 1

‘7mDx

NATIONAL ADVISORYCOMMITTEEFORAERONAUTICS

Figure l.- Geometric relation of blade-element forcesand velocities.

c’

[0 ‘

/ / / ‘A / / ‘/

,8 / e / A //

/ ‘/

/ // “,6 , / /

/ / / NACA uirfoi/x=.3 .451.6 .8/ .9/ .95]‘ de i nat..on

,4 Q;4/ /

/ / / / ///

/ / / i//

/[/

16- 1~3 130.45 )6- 228 /085.6 16- 282 0905,7 /6- 297 0800

,2 .8 16- 295 0695.9 /6- 252 0577

/ / / ,95 /6-( 203 0476—/

o ‘ / / / //.// / / NATIONAL ADVISORY, i

/, COMMITTE~FW AERONAUTICS

72A / / A I

-4 2$ 8 /jo3 -2 ~ g

-4 -? ;6 g-4 0-2 46 /0

-4 -2 “2 4 g-4 _-f 2$ 2 ;0

-2/Ang/e of Othck, ‘d , eg

46 /0

(a) CL curvee..

Figure 2.- ‘1’W@diMenSlOnal airfoil characteristics. NACA 10-308-03 propeller sectione.Mach number, 0.3.

NACA ARR No. L6E22 Fig. 2b

.Cw.m ./2hw.

0 .& .G9./2 ./6

0 .04.08 ./2

0.04 .C19

0.04

(JL

NATIONAL ADVISORY

(b) Tan ~ curves. COMMITTEEFM AERONAUTICS

Figure 2.- Concluded.

t\ —

=3PWJ.

—477——40.9 ~

.-

I N

— —..

P’\ ~cyh’ndricff!-q

section

p

,687

I .8 /?a2iiusra+h, X

‘9,95

NATIONAL ADVISORYCONMITTEEFORAERONAUTICS

Figure 4.- Dimensional detaila of teat setup. (Ul dimenslone except x’ are In inches. )&

cdkdoldcover

plates

-+

zo●

1

I

Figure 5.- Close-up showing spinner cut-outs andcelluloid cover plates.

ul

—1’

NACA ARR No. L6E22 Fig. 6

I J II

.04( — - Leodflgedge

&d

~ .\

Developed plun form )— ~

.04- — .

.16

./4 (

,/2\\ ,%

,10 \%

$

.08 -b *

7– .$pjn~er surfoce ‘ \

.06 — / ~ — ,3

,04 ~

.02 ‘ ‘. ~NATIONAL ADVISORY

COMMITTEEFORAERONAUTICS

?2 .3 .4 .5 .6 .7 .8 ,9 Lo”x

Figure 6.- glnde-form curves and C%

distribution of KACA propeller 1O-3O8-O3.

Fig. 7a NACA ARR No. L6E22

24Pmpe//er

55 s45s — - —

20 “x 30s --------”

\

12 \\\

&\

h8 \

$ ‘

Q.

,4

Y Y

o

<

h-4 i \

N<\ >,

NATIONAL ADVISORY

COMMITTEEFORAERONAUTICS\

-8

.3 .4 ,5 .6 .7 .8 .9 /.0P

(a) Blade-twist curves.

Figure ‘7.- Pitch distrib~tfon of propellers 55S, 45S, and 30S.

NACA ARR No. L6E22 Fig. 7b

Pkii5!/&-45~____—

4?8

~~~ -----------------

! I,$,‘t,

40\\‘\\.\\

Z6‘...‘.- \ P -------*75R= 590‘..- — --------- ------

— -52 ~ ~

/ —

28PD 45-”-

24 “ — ~ -------- — L------------------

~ ~— “

20 0-/ ‘

350 —

L6 — — ~ - — — >“ -- — — — ‘ ‘- ‘------------------- -- --

/

/2 25 0—----------------/ ~ — ~ ----->---/ ~ —.

/- /

.8 -------------.--_--~ ~ ~

w ~~. ---/50\ .\-----

4NATIONAL ADVISORY

COMMITTEE FDAASRDNAUTICS

?2 .3 4 .5I

~ .6 .7 .8 .; la

(b) Geometric-pitch curves.

Figure ~.- Concluded.

‘=9. . .

&.03

●

* A/ace//e rod’us inp/One of Suruefj

LO(3 ./!4

?

\ .

..

‘04---+ NATIONAL ADVISORY

COMMITTEE FORAERONAUTICS

,2 .3 .4 .5 .6 .7x

.8 .9

>Figure 8.- Velocity distribution 7; inches behind propeller disk. Propeller removed.

*

.Zzo.

r

dcTcjx

.10‘ u

.08 \ .

\ \ \

.06 \ \

30” \

,04 \ \

\ \ ‘ ‘ / ‘

,02 \ L

\ ) \’ ‘(\ ~ y. ,’ \~ : ~-

/ ~45 \ /

– .24- < ‘ / / ‘\ \: \ J 60°

0 \ * 2 k “/ ‘

\ ‘~ ,!,] ,’ > ,,: >~ : Calculated 3

-.02; / Calculated%

\\’ \’ \ \

.12‘+ k ‘ Y

\ .—

\ \atconstant CP

.08 \\ ,

Force teat ~ ---- ——-

-.04 .04

\

\1

\ \\ \

-,06 \i5” p5” 35° 40° 45° 50° 55

I I NATIONAL ADVISORYCOMNITTSSF~MLISAUTKS

-.08 I I

o ,4 .8 1.2 1.6 2.0 24 2.8 3.2 3.6 4.0 4,4 4.8 5.2 5.6 6.0

J(a) x..0.3J

Figure 9.. Element thrust coefficients. propeller 553.

zo.

g

dCT

dx

.16

5~

.14 \\ \

\ \\, \

‘.12 \\

\

\\> \\ \ \ Cp

,10\ \ \

1\ \ \ \/ ‘

\ \ \ “’\ \- ,40— — — /

\ \~ ‘

//

\ \ \ \ \ v \’J\ \ L ‘.3E.08 ! \

// F

\ vY ‘ \

. .32 / -/ “

0 ‘0

/ / /\

.06 \ :: “\ ., ‘ + i -.28 / ‘ / / <\

/ - / / ‘ /“

\ \\ \’ ‘i (,

\

‘ -+\’

4

1- – -

/

, ./

‘

+ -

=

/ ;

/

~ ‘

/ 650

\ \.04 .20

- / ~

\1

\ ‘

‘.16 /\

\ ~ “ “ / “Y‘ calculated%

.02 \

\\ .’ ,r \ !,

dCT, Calculated ~

\——

\ \

\,0& ‘,

at constant Cp\

0 \ Force test % . ..- ----

\ \ \ ,\

.02 \ __\ __ \ ‘1 _ s \ \ ‘ \~,75R = I 5° 25° 30° 3T 40° 45° 50” 55 0 60 0

I I NATIONAL ADVISORY,COMNITTU ~ AUOSALITICS-

.040 .4 .8 1.2 ).6 2.0 24 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6 t

J(b) x .0.45,

Figure 9.- Continued.

—.Pml.

U3u

dcTdx

.32

,28 Calculated 2— dCT

55° Calculated =——

{

\\ at constant Cp

.24- \ \ Force test ~

n \—- —--—

t ,\

\\

,20 i \\

\ \. \ \ .\ /

\, \\

\ \\

\\ , f\ . Cp

,16 L\

\ . \ \ ‘ \ \ ‘ $lo\\

\\

\ i-7 \ ‘

\ ‘.36. \ . \

L \ ~.x .32 \

.12;

+

‘

,.28

L > ‘ : < = “ ~’ ‘ L

\24

\ . \

.08- 1 \ . +~n”~l” ] I I

y \ ~- “L . ~ --t+ W-11-i-i’-wl-l I I\ \\ \“‘ \

I 1= t I T l\I I

I I I II I [\ I I

I I\l 1.04 b 1 I 1 \ 1 1 I I 1 \ \

\

A \ \ I 1\ \

\ 3 \l \I

&5R” = 15” 25° 30” 35° 40” 45” 50° 55° 60” 65”

0 .4 .8 1.2 1.6 2.o 2.4 2.8 3.2 3.6 4.0 4.4 . 4.8 5.2 ti6 6.0J ~TW MVISOllY

(C) X -().6. cream KUMKUMIW

Figure 9.- Continued.

,

‘=3l-.ml.

d CT

dx

““rrrrr 1 1 I

t

1 I I I I I I I I 1 1—0 t.28-

\ \\

Y h

.24\

\ 1“.1

\ \\

h\ rh.20 \

,- \.Ib

.12

.08

.04

0 ,4 .8 1.2 1.6 2.0 2.4 2.8 3.2

4yu’Kt’+L’id I I I

I36 4.0 44- 4.8 5.2 5s6 6.0

u\

\

.

\\

\\

\ \ \.

\ \

\ \\

\

\ \’

:0 \ ‘ b) 60° 65°

I i I I I I I I I I I I

J NATIONAL ADVISORY

(d) X .0.7. COMHlllEE MS ASSONAVTKS

>‘m

zo,Piture 9.. Continued.

rOa

:N

I

dcTdx

.36

I

.32Calculated %’ .

dCT\ Calculated ~

——

.28atwn8tnnt CD

‘ For& teet ~ ------- —

.24 \

bi\.20

.16 i 1

\ Y ‘ \\. ‘ ‘\ .;

:,20

\ .,7 ~’ “. ‘~Y \ .16

\ ‘\

\

\’ 1. .\

\,12\

\\

\

L-.08 \ . \

\\ !

\\ J h\ .1 \ \ \

— \ ‘ ‘\ “

.

4 ,’ ; \,08 i

\

I\ \ \,\

\

\, \ 7 .

.04 \ \ \

I_ _ \\

\ \ \

\ \

\

A,,~~- = 5“ -lzl” 30” 35° 40’ “ 450 500 55 0 60° 65°

0 ,4 ,8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8” !j.2

J5.6 6.0

NATIONAL ADVISORY

(e) x .0.8. CMM1l’rss m u.saWMTlcs

Pigure 9.- Continued.

zo.

U3m

,c~

dx

.325L o

.28\ . \ Calculated %?

I \\\ \ Cp \ dCT

Calculated TI \

“24FFFH

od w

(f) x .0.9. NATIONAL ADVISORYCOHMllTLZEFa AERDSAUTICS z

Figure 9.. Continual . 0.

rm

EN3

dcTdx

.32<

!$.28

Calculated

55°\ /

c~lculated % ——

\at constant Cp

.24- \\ .---.-—\

..,20

\, \ ‘ J\

\.16 ,

\{\

\ ‘ +\

,12\ \ “.12

7

\1%I .08-~ \

.08.

\ \ \ \\ \ \ “\

\ \ * /p\

J “ \

\’ k\ \\ \

.\ k’ > + ,, \

,04 1 i \ .

\

i \\

1 \ \ i\\ \

45 \

0 \ h

\I

. .

\1

\\ ,

\ >J L

.75R = I 5° 40” 45° 50” 55° 60° 65°-.04 I

o ,4 .8 1.2 1.6 2.0 24 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6 6.0

JNATICUU MVISORY

(g) x .9.95. CcHllm m MmlmvlKs

Figure 9.. Concluded.

dCT

dx,

.,-1 Ill 1111 I

.14

.12

10

I I I 1 I I I I 1 1 1 I I >1 /1 1-

.08t-

1

.06

‘E

04

.02

4--4-4C“’”’’””% l--l-HI---H Ca’c:a:d.*_

.. -..”

II i 1 I

-t-t--t

aL c0n6LanL ~P

I IFI. l\,\lw\l b?”f I I l\Force test ~

‘------- tttio \ \ I

\\

\ \ \ \l

d

/

\

/ \ \

\

\\

\ ‘ 450\

-.02 B.75~ = ~’ 25° 350 40° 45°I I I I I COMHITTEEMSAESOSAVTKS

-.040 ,4 .8 1 , 11.2 1.6 2.0 2.4 2.8 3.2 3,6 4.0 4.4 4.8 5.2 5.6 6,0

+2%”iI I I I I I 1 I I I

NATIOMAL ADVISORYi ,

IJ

(a) x .0.3.

Figure 10. - Element thrust cceff ir,ierits. Pro~ller 45S.

,321 I I I i I

J llATIONAI.ADVISORY(b) X .045. COHllmFaMmlMmcs

Figure10. - Continued.

71Y—dCTX H

, , 1 1 1 1 ,

dCT I I.28‘

Calculated

Calculated “m—. J

at con9tant Cp

,24 Force test * --------

\

,20 \\

4!r\.16 \ .

\,\

/ ~ // ~ /

s— b

\ / - /

,12 - ~ /~ = — — - — —~\ \\ \

\ .36— -

YI m

/

.08\ ,1 \\ \ ,4 ‘ \\

\

\‘ L\

&\l- / -

p\ T ~ - ~ /

\F “ -_ - -+ : /

/ ~“

.04 \

\\ \ ‘ *

‘.12

L , .08_/ –

/ i

\\

Y- 60”

0\ 55 “

@.75R - ‘- 15 25 35“ 40 u 45” 50”I

,4 .8 1,2 1.6 2.0 2.4 ?,8 3.2 3,6 4.0 4.4 ,48 52 5.6 6.0

‘%wal.

dC~

.32Calculated %? L

.28 —.calculated‘% .—~.5° \ at wnntant Cp

\ Force te8t !# ----- --

.24 \\ \\ \ \\\ \

,20 \ \3~0 4

*\ \.\

\,16

\\ > \ \ \\ Y\ ‘y

PA\ i v . \’ \ ‘.40

\ \ \ >

\

\ ‘%

.12\ \

\ . \\ \ \\ ‘> .+ i’ ~ \ / -~ : ‘ ~ \

\ i Y ~ -\ ~ ~\ . \~ _ —

,08 \ \ \ L

\\ A .- +~ _ -

~ .12 \ 1\ \ \“‘ ‘ . ‘~ ‘h 65A

.04— — — — — – %— . I I

~35R = Is ? 25J 35 4 55 / 60

0 .4 .8 1.2 1.6 2.0 24 2.8 3.2 3.6 4.0 4.4 4,8 5.2 5,6 6.0J

(C) X .0.6.NATIONAL ADVISORY

c.c4mll17EE~ ~~s

Figure ~. - Continued.

z>0>

zo.

t-(YJ

Eto

.32

&

,28 \ Calculated~

\calculated % _\ \

\\ at constant Cp

,24\ ,

Force test35: \

!# _______

\ \

J \ \ ‘ \\ \’ \ \

.20 . \L \ . \ \ cp’ \

.t6 \ \

\’\, ‘\1 \ ~~ \ \ \ \ \

,12.

\’\\ \

> . .20” h \\ \ \‘

\\ \

\ \\ \ \’ \\ \ \ \ !’ \ \

\ \.08

\,\\

\\ “ + 2 \ .’l <.

\

\ .: ~~

\

.“ < \. , \, ‘

\ \ \.04

\

\. \ \ \

\

\\

\

\ >

\

\.\

\

\ -1 \ \ \ \ \

o1~,75R =

\ \ >

I 5“ 25“ 35“ 4C“ 45” 50” 55 “ 60” 65 ‘

o .4 .8 1.2 1.6 2.0 2.4 2,8 3.2 3.6 4.0 4.4 4.8 5,2 5.6 6.0

J NATIWAL ADVISORY

(d) X .0.7. mll-lu m MMIIAUTKS

Figure 10. - Continued.

IJola.

dcTdx

.32- 45”\

\\ \

.28 -Calculated $# —.

\\

dCT\ Calculated =

\

\ ,\

.—

3’;0

A : \\at conetant Cp

,24\ .

Force teet ~

\

--__-— _

\ k 1

\ \\

.20\\

\

\\

\ \.16

\ ,,12 \

\ \

,08

\

\ \\

.04. ‘ \ \

.04

\ \- ‘ k ,.

\

T,

.75R= I5° 7.50

35 400

450

50”\ 55‘0

* 600

O&65’ \

.4 .8 1.2 1.6 2.0 2.4 2.8 3.2 56 4.0 4.4 4.8 5.2° 5.6 6.(3L1 NATIONAL ADVISORY

(e) x .0.8. COMHITTtE Fm ASROMAUTICS

Figure 10. - Continued.

zo●

dcTdx

I

I

,32

Calculated %1

.28dCT

\ Calculated ~ ~\

\.—

at constant Cp :

.24Y> Force test # --------

\

\ \ 4\

!\

,20 \ \\’ \’ \

A\

\

\\ ‘ i \ \’ ‘ Cp \ \\ \

.16 N\.28

\

\“ ~~,12 A

\

‘ :) 2\ \\ \\ ,1 \\

.08 \

\ \, \ \“‘0’34 .\ w h \ .! .; : .1 \,

.04 \ \

\

- , ..0 4-\

\\,

\k \

\

&. 5“\\ \ I

?50350 40” 45° 50 ‘

0i 55

0\ 600 65

0 .4 .8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6 6.0

J NATIONAL ADVISORY

(r) x .0.9.SOWITTEE FOEMBWAUTKS

Fieure IO. - Continued.

zo.

I

I

dCTdx

.32

\

,28 \

\calculated q

\dC~

\ ,Calculated fi

\.—

,24 at constant Cp

\ , ~

\

\\

Force LeSt ~ --------\

.20 \ \\ ,

3i\ Y \ \

\\ > ‘\ \

\

‘i ,’ ,’ ~Cp

.16 \ \ }40 !\

‘ 1’ \’ .> %’6 \\ \

\ \‘,\

,, \ \.’, .\{’ \: . \

.3) ,

.12,28

b .24 \\’ \\

L .,\ 1\ \

\ J ,Y 0’ \ !il \\ \\ \P \ \

\ \ \\ \,\- \

I \,’, ‘\ ‘\’\’ ,~ {,04 \ “\\ \ \ ;08

\ \ \ \ ,\ \

\\ .04- ‘

, \ \ \\‘\\

o \

\ \ \

\ \\

\ \

\ ,< \

\

\\

p\ \

-.04 \\

\ \

—. ‘\ \ \ \

,75R = 15° 25° 35° 40° 4!5° 50° 55° 60° 65°,080 1 ,; 1 .8 , ‘2 I I I I I i

1,6 2.0 2.4 2.8 3.2 3.6 4.o 4.4 4.8 5.2 5.6 6.0J

NATIONAL ADVISORYtg) x .CL9S. COHMITTK FM 41ROMAUTICS

Figure 10. - Concluded .

‘=2

;.

Po‘w

zo.

rcn

EN

dC-rdx

.16.

,14

.12

\ \ \ , .40/ “/ /.10

\ ,A/ y / / “ <36 / // “

\ / ‘ // /

30:k “\

\&32 / -/ / / \

,08 \ / 1+ “/ / /( 60“—

\ \ / ‘ /,28 \.\/

\.06 1 \

\,\

.04 \\ \

\ \ ..16‘ /CalCU1ated $?

\\ .Y ‘)\,\

w \- .\

\ / \

;02 ‘ –.12’< calculated‘#\

\ :/

50”’\ atconstant Cp

/ ~

\,< J

\-,08

/45°

‘Force test ~ ‘-------

0 45”’

-.02 flJsR = 15-1 25”wrlatu.ADvlsOw

*ITTSS Ml ImawlKs

Io 4 .8 1.2 1.6 2.0 2.4 2.8 3,2 3.6 4.0 44 4.8 5.2 5,6 6.0

J(a) x .0.3.

Figure 11. - Element thrust coefficient.. Propeller 30S.

zo.

—

m

.

.32

.28

.24

.20

dcT .,6dx

.12

.08

.04

G

-.04

calculated #

dC~Calculated fi

——

al constant CD

55°,Force test ~ ---- —-.

\\

\/ — \

\

3.\

\\

o \ \\ 45\ \ \\ \

\ \\ / — \ ‘ \

\ \\ \ \ \\

\

\\

;04 ~\

\ \5 .40 45

\l\ \4 .8 1.2 1.6 2.0 2.4 2$ 3.2 3.6 4.0 4.4 4.8 5.2 5.6 6

J(b) X .0.46.

NATIONAL ADVISORYCOMMITTEEFOAASRWAVTICS

Figure Il. - ConLinued.

o!20. I

m

EI

N

dCTdx

.28 .~\\

55 Calculated 2“

4<\ \ dCT

.24 36,\ Calculated ~ _

\\

\\ \ \

\\ at e0n8tant Cp

\\

\

\

\ Force test g ----- --\

.20 , \ \

‘\1

.16

\\

,12

.08

\k \ ~ I\’, ma \ \ \ v ,\ I \

1 \

.04 RN-+--PI Ill II Fdii \ \ i\ \ Yy

\\ A. \ L 3 +

rd\ll—1~ 1111 11-.+1

_B.&~- = 1: d , 30; 3s 40 4s 50° k5°K bi ml IO 4 .8 1.2 1.6 2.0 24 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5,6 6.0

1 m\ 1 1 i 1 1\ 1 1 1 1 1 pa+

5

zo.

1

d(C) X .o.6.

NATIONAL ABVIWYUMITTEE FM MMIM!TKS

Qiturc 11. - Continued.

dc~dx

.32

/550’.

4< \,28

\

I\

/36-., \ \

\,., ‘ ~~x R

\ \ / Force t,eet’ $

,24

_— -----\

\\j /\

\ \ \\ \ ,\

,20 \ \ \ /\ “ \

\ \ \. ( k \\ \

d ,’ \\

\

\ i :, \ ‘<\.16 \$ ‘ ‘N, ‘L\

\.f2 \

‘i x \ ‘ ‘20

\ ‘1 .1

‘.16 \ \‘ .12 \\ ‘\ \\ \’ \ \

.0a \

\ ‘i \ :.08

4 ., - \ 1 ,\\ \ > \: ‘ \\ ‘< ;,\

\:04 ‘\

.o~s\\ . \

\ \\

\\x .

— \ \\ \

o “ \ , \ \ \ \ \ <

/ (Z75R .= 15° 75; 30 35° 40° 45° 500

\ 5 5°0

6 )

-.040 .4 .81,2 1.6 2,0 2.4 2,8 3.2 3.6 4.0 4.4 4.8 5.2 5,6 6.0

J(d) X .0.7.

NATIONAL ADVISORYCOWITTEE fa ASMAVTICS

Figure U.- Continued.

zo.

dcT

Cix

55”-,

.3245:

\ Calculated\ 2’

!\ \

dCTCalculated ~

.28\ \

.—

\\

at constant CP

““30°- =\

\ i Force test !KJ .- —----

\ I

\ \ \\ \

,24 - \ \ \ ‘\\

‘\ \, \ \ \\ 1;, .y \

,20hi\ \ ,1 ,’ < :.

1

y ‘ .k < \,,\ I\ cp\

\ 40,16 -

\\..?6 \

\ ‘, ~\ \\\\} \ \

\

‘ ,35 \

\“ ‘1 k, \

24.28 I

\; \ \ \\ \

.12h \ .20 \ \

\\

\ ~6 \ . \ \\ \ .12 d \ .1 .\

Y \ ‘ \\

\ \

\ ‘ y 08-7 \ \ \\ 1% “. ,~ \’ \ ‘ ~\

,08 \\

{\

\\

\-,~4

\ .l \~ L

.04 \ v “ \ v \, y -. \\ -

\ \ \ \\

\

\ \

o \ \ \’ \ \ ‘~ {

\\i \

\4

B.75R = I 25” 30° 35” 40” 45” 50” 55” 60” 65“-,04 1 I I I

oi

,4 .8 1.2 1.6 2.f3 2.4 2,8 3.2 3.6 4.0 4.4 4.8 5,2 5.6 6.0d

NATIONAL ADVISORY

(e) x .0.8. COMMITTEEK4 MMSAUTKS

Figure 11. - Cont:nued.

zo●

dCTdx

,36Calculated ~

dC~.32 Calculated ~’

.—

.28

.24

.20

,16

.12

.08

.04

0

-.04I1I h I1I I 11 I II I125° 30°135” ]40° I 45° I 150° I 55” po” I 65=

,4 .8 L2 1.6 2.0 2.4 28 3.2 36 4.0 44 4.8 5.2 5.6 6.0J

NATIONAL ADVISORYz

(f) x .0.9. 0WMITTU~ MMMUTKS

Figure Ii. - Continued..

K1%

dCTdx

J )MTw ADW~Y

(g) x .0.95. cammcsFMMmllmKs

Figure Ii. - Concluded.

dC~

dx

J(a) K .0.3.

‘=9r.

m.

zo.

Figure 12. - Element torque coerricients. Propeller 55S.

dcQdx

H--H+ tlmw A/j )\/ A /1 / A

.U

.0

.0

.0

W1714TH

o .4 .8 1,2 1.6 .2.0 2,4 28

I I I I I I I I I Ic&...-.- ,-.I !

3.2 3,6 4.0 4.4 4.8 5.2 5.6 6.0

z0.

J

(b) X -0.45.

Figure 12. - Continued.

dCQdx

I II

rl I&l In 1 1 L T \l I I

.(JZ—,’0 I~,uo~ \4 \ \ ! n , \

- — ~. .,04 \ \ \ \ \o \ \

o .4 .8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5,6 6.0J

NATIONAL ADVISORY

(C] X .0.6. COMMITTEEFM ASSOMUTICS

Figure 12. - Continued.

.

CICQdx

.2

.2

.2

,1

.1

.1

:.1

.1

.0

.06

.04I I L I l\ I I I

.02

n“O .4 .8 1.2 16 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6 6.0

LI

(d) X .0.7.NATIONAL ADVl~Y

~llltE FM AFAWW’FKS

Figure 12. - Continued.

zo.

rm

EN

dCQdx

.24

.22

.20

,18

.16

.14

.12

.10

.08

.06

,04

.02

00 ,4 .8 1.2 1.6 2,0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6 6.0J

(e) x -0.8. NATIONAL ADVISORYCOMISITTEEFOSAEROSAVTKS

Figure 12, - Continued.

zo.

dCQdx

.20

,18

.16

,14

.12

,10

.08

.06

.04

,02

00 ,4 ,8 ,21.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6

J(f)x .0.9. NATIoW ADvIsMy

til~[E n ~AUIKSFieure 12.- Continued.

zo.

‘%Jl-.

m.

1-N3m

.18

.16

.14

.12

.10

,08

.06

,04

,02

n“o .4 Al 1.2 1.6 2,o 2.4 2.8 3.2 3.6 4.0 4.4 4.@ 5.2 5.6

JNATIONU AIJvtsonv

cMNll?Et ml MADHuJltcs

(g) x - 0.95. zo.’Figure 12. - Concluded.

dCQdx

.16

.14

!1o

,12 1 I I I I I I I I I I I I I I Ii 6:0+-+++

4 I I I I I I I I I \ I I I ! ! I I I I

1 1 I i I 1 I,08 I I I I

I I 5’0°-. +-?14,, .2 - K 1Y

I I I 1 I 1 t I I J L

.02+ — /.,-r40> Xwi /U.-L25

.-— —0.9 0

J(a) x .0.3.

MTiO?lMAWl~YCWMITW ~ MWWIKS

>

,%

zo.

=9t-.Qa.

IJWP

Figure 13. - Eleuent torque coef f icientB. Prowller 45S.

.20 -

.18 ~.75R~ ~ — . \

\

.16 65” $)dCg

/

Calculatedx / ./ / ~ .

/

.14 Calculated !# /

/ /at constant Cp

+ c /

.12

60°_/

.10 \ / ‘ // / / /

/ / /

.08,40, /

55°/ /

\ 0 <36 ‘ / / ‘/ ~ <

.06

.04 45: — \

40 .:_ — -

.02

— I5° NATIOMAL ADVISORY

\ F \ COHNITTEEFDt AIIOllAVllCS

o .4 .8 1.2 1.6 2.0 2.4 2.8 3,2 3.6 4.0 4.4 4.8 5.2 5.6 6.oJ

(b)X-0.45.

Fipure 15. - ~ontinued.

Pw0’

z.o.

v

dCadx

.20

P.75R –65”/ -

.18

II I II I II , , I I I I , I I I I I I Ilhl I I II I {,16 I I I I 1 I IdC~

\

CalculatedK \

.14Calculated ~ —— 60°

at cons Lant CD \

,\ \

.12

\55:

!

,10‘ Cp\

-+~

.08 50°\

.+-\

\. 45” .32 \ \

.06 \ .. —~ —-

400..\ \ .24 ‘,

\ ~ \ \ \.04- 35” \ \ ‘\ .20 A

25°—

\ -.* ‘\- - \, _ _ _ _ ~ _ _ _ _ _ _ _,. ‘‘.12

.02 ~I5°. \ .08--‘j I

\, / IhTlOISM ADVISORY\M 13MM11-lIE m MsalAullcs

00\

4 .8 1.2 1.6 2.o 2.4 2.8 3.2 3.6 4.0 4.4 ft~ 5.2 5,6 (3.0

J

(C) x -0.6.Figure l~. -Continued.

.04

.02 WH?TTlJ

(d) X .0.7.NATIONAL ADVISORY

COaMlrrf[ FaAsscuAuTKs

Figure 13. - Continued.

wwCL

>?3?J

zo●

—

dCQd~

J

(e) x .0.8.

zo.

,

Figure 13.. Continued.

dCQ

dx

oJ

(f) x .0.9. NATIONAL ADVISORYCOUMISIEf Fa ASMSNltKS

Figure I>. - Continued.

z0.

,

dCQdx

JNATIWAL ADVISORY

(g)x .0.%. C4wllm m MsosNJllcs

Figure Ij.. Concluded.

zo.

iv

dCQdx

J(a) x .(!.3.

Figure lk. - Element torque coefficient. Propeller 3Ct3.

dc(ad%

.20

.18

.16

.14

.12

,10

.08

.06

.04

.02

zo.

-.021 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I-—0 .4 .3 1.2 1.6 20 2.4 Z.? 3.2 3.6 4.0 4.4 4.8 5.2 5.6 6.0 6.4

I(b) X .0.45.

Figure 14.-Continued.9l-.

m.

I-J&u

dCQdx

4

wIP(a

J(C) X -L16.

Figure 14.- Continued.

z0..

oLJ

(d) % .0.7.NATIOIIALMV~Y

CCMITTEE~ ~KS

Figure 14.- Continued.

zo.

od

(e) x .08,NATIONAL ADtlSORY

COHNITTEEFOI AJZSWAIJTICS

‘=3l--‘m.

zo.

Figure 14. - Continued.

I

I

?

dCQdx

J NATIW ABVIS~Y

(f) x .0.9. Comlllss m ~Ks

zo.

I

Figure IL. - Continued.

dCadx

.0

.0

-.00

P?Jm

z0“. I

JMArIONAL ADVISORY

(g) x .0.65. ~lllFXfm ASSOSNJTKS Pm

Figure 1~-- Concluded.EN

1

I

—

./2

.08

,04I I I I r .w- 1 I ~Tl I I Y\ I I I I I I R I I !1NATIONALADvlsilnY

oCmm-r[trm MBCWJTK.5

I I I \ \ ( 1 I , 1.2 4 .6 .8 1.0 /2 /.4 J6 !.8 20 22

d 2; 2’6 2’8 3“0 323.4 3,6 3.8 4,0 4,2 .4.4 4,6

x

Fiire /5. - Rr@eIler opetitiq chod. P@%7?er 55S.

IJ

m

zo.

Figure /6.- Propel{er operating cfmr~ Propeller 45.5.r’cm

\

..76

.72

,68

,64

,60

.36

,52

.48

.44

~ .40

‘.36

.32

.28-.

..Z4

.20

.(6

,12

.08

,04

/ A ,[1 }X / r / 4 / /

/ ,-, k / “. L- ‘ / ‘ / / ‘ A.,, \ /’ .’ / “ / ““.7 PiAl W,m”

/ / --- m m -.s

\ ? c- - : :; ‘ : - “ -- “ \

r – – – – – – “ – ‘ – – – – – – – – – – – – –

02,2 2.4>,62.8,3.0.323.436 3.640424.44.64,8 5D 5234376 (78 6,0

Figure17-Propelleropemllzq ch@. ~roPefJer. 3~L$.

zo.

inRNJ

‘=3P

W.

.

. =3,Pm.

c

dImllolm ADVISORY

Ft@we Ma- 7WusFwxdfiLient U&rves. Propel&r S5S. Cmmlnula —Ks

!2

.

z0.

.

c+

--------

I

>?3?3

zo.

figure /9-Thrust-cOeff/cienicurves.Ropeller45S. ‘

‘7l--

m.

.2’0If?

./2

./0

.08

Figure 20. - Thrust- coefficient curves ~rO~e//c?r 30.S,

‘zo.

‘.\ . 55s\ .\.

‘\ \ -. \ k \ Cp453—————~.,

./4\ N ., 303--------------”\ \\ .\ .

\ . ‘.\ \ \50 I‘.‘. w

./2 \\ \\ \

\ \

./0 \\CT

.(8\

‘1.06 \ ,08 \ “ % & ‘ ~~ \ .. w\, ~, “%\h+. c. -. -.%

,... ‘.\ b. --- -.. \ -.... -..

‘. 04 \ -.. -..##

.. . <

~... ‘.

. . -.> 1 .\ ‘\. -.-.. L‘.

-. -x..’ --- .

,02NATIONALADVISORY

C~Hl~EE fW #lSOUAUTKS

‘O 4 .8 12 /61

20 24 ~ 2.8 .52 36 40 44485256

zo.

%JP

m.

“’-===3!

Fiswe 21. - C0Mpari80kI Of CT at C~8tUIt ValUOS Of (+..

459, ad 30S.Prop*ll*rs 55S,

m1-

Fig. 22a-c NACA ARR No. L6E22

4- Sptmer surface.2 ‘

/.1

/

. 0MeawMcu/cu/utt - – ---

-1-“‘ (a) propeller 55S; J,1.97.L 1 1 1

P-.. j“nner wrl’bce

/ ‘“/“ \,1 / / \\

<“ “dc,-

#dx . - /

o

+ I

(b) Propeller45S;J, 2.03.

.

(c) prope~er 30S; J,2.17.x

NATIONAL ADVISORY

COMMITTEE FORAERONAUTICS

Figure22. - Comparisons of measured andcalculatedthrustloadingourvesconstant power coefficient.

P~.75R = 45°; cp = Oz.

at

[0

.8

.6

7

.4

.2

0LJ

(0) Tqke- off. CP=0.030.Pro,05e~/er

—— —%

5;——. - ————

10

.9

7

.8

.7

“6L2 /4 /6 [8 20 22 24u

(b) C/imb. Cp. 0.246

7 —.9 _________________-_------ — -

----‘8zb 28 30 W J4 36 .38

d ●

k) High spare! CP=0.246.

Lo

7’- - — -.9 H

FF———l——I—L— L—4—-L-I—-L I I I_—-1

(d) High SP65W’.@ =0.400.

10

7

.9 —-.-——.___ ___ --- -—— - .--

-- .

“826 28 JO .5?2 34 36 .5.8

‘=3wm.

d NATWAWl~YaiylmumNmlbmc5 N(e)High.speeciCp=0.320.

yconstffnt vu/ues of Cp. m

Pmpe/’/er55s45s ———

.20 3os ——– ——––– t

./6 / ~// <

0/ %

/ ●0./2 \

~ /

dx -Spinner /

4% swfuce,. /

74

aA

r NATIONAL ADVISORYCOMMITTEEFORAERONAUTICS

o.2 3 .4 .5 .6 .7 .6 .9 L(2

x

(a) Thrust.

Figure 4.- Grading curves at take-off. Cp = 0.080; J = 0.80.

N&P

zo.

______. .. ,8.

.028Prope//er

555 / ~ .45s ——

/

D24 “ 39s -------/- “/ 4

// \

D20

,0/6

dc&Z_

)

.0/2 “

.008 1

/‘,-

/“/

.Ct?4 /’ //

/ / NATIONAL ADVISORYCOMMITTEEFM AEROUAUTKS

o.2’ .9 .4 05 .6 .7 -& .0 M

x

--=5!

I

z0.

‘%l-.

w.

NJI&CT(b)Torque.

Figure &.- Concluded.

.24

.20

.16

, /2

&dx

.08

.04

0,2 Y .3 .4 .5 .6 .7 .8 .!9 ko

x(a) Thrust.

zo.

Figure 25.- Gradingcurvesat climb.Cp = 0.246; J = 2.00.

,...

Prop9//ev-I

.104.5s ———30s ––– - –––– — <

.08 r=”—

\l\

.06 I

*

.04 ‘ /

\\

/ /

0’ ‘ / r

NATIONAL ADVISORY

COMMITTEEFORAERONAUTICS

702 “2 .3 .4 .5 .6 .7 *B .9 10

x

(b) Torque.

Figure 25. - Ccmcludecl.

I

zo.

rmm

R

-Jl--

m.

NJulu

‘%1

.16

,/2I \

dc,dx / /

/-/

————/ /

.04 /

/ NATIONAL ADVISORY/ COMMITTEE FORAERONAUTICS

\0’

0

.2 ‘3 .4 .s .6 .7 ●8 .9 Lox

(a} Thrust.

Figure 26.- Grading curves at high speed. Cp = 0.2h6; J = 3.15.

P‘m.

I

1I

I

zo.

I

./0

●

.&

*

.04

●O2

#

PrOpe//er I55s

1111111455——— 1111

II I I I1 1 1 I 1

, , I 1 I 1 1 t 1 1 I 1 I 1 12 .3 .4 .5 .6 .7 .8 .Q h

x

(b) Torque.

Fig~e 26.. Concluded.

zo.

-=

I

,20

./6

Gdx /2

.0$

.04

c).2 *3 .4 .5 .6 .7 .8 .9 Lo

x

(a) Thrust.

Figure 27.- Orading curves at high speed. Cp = O.LOO; J = 50000

,,(I!15

.43!!!

,“$? .$ ~ .6

“==!

I

.7 98 .9

[h’~1Torque.

l?’:flg,um 27. - Concluded. NJ<u

./6

./2

g

.08

.04

0.2

I

/

/

// Y

COMMITTEE F~ AERONAUTICS

I I I.3 .4 A

.d

(a

Figure 28. - ~rad~ng curves

.6 .7 .8 .9 Lox

Thrust .

at high speed.CP = 0.320;J = 3.8o.

zo.

Pr-ope/ler5.5s

45~—_—

30$ ------------

/[ 0’ I ! I J

A+H-FRt’H-:t-m”’i “N‘ii iX&Q_

.04 /

.02

COMMITTEEFORAERONAUTICS

o,2 %3 .4 .5 .6 .7 .8 ,9 Lo

x

zo.

(b) Torque.

FiSure 22 .- Cor:cluded.

Nalu

28

.?%;~ ‘;.:LL .szkfuz —L5= 7!2” 75° P- /?75~ -60:“1 I I

24 / /g j‘! ! I ! I

❑ l I

Propeller J_I I I

d I I I \ I ! I 55s ~I

23 35 45X I I I I20 45J El ~I

I3030 ~! /

I I~ /6 I !

I Ill II I I I I I I

Tk

II

< /2I I I

Ill II I 01 \ I I I-Q I I \ oo-#07 ~R @~

88 .I Ill II I I I I

r ! \ ! ! > \ \ X=.3

~ III Ill II I I I I \ I I

1 I ~ ~ _

kiI

K ,; ;I II “ I 07 ~ L I I

— _ — . &@5 Iw?” ~ — I — _

/1 Ill II I I “1 I I . I4 -L1 ! !

-1--PT II I ‘1 I I Io 1 :?5I 1 I

I _ __l . . . — -L — — — .8 I\

—Ill II I I I I I g5— — - 1 I

_l ml .@L — -t--- — I — -I I

I I ~~ +

!I Ill---l 7- * Qt- — I NATIONAL ADVISORY

‘8 *I ,111 ~1 1~1 ~~ ; ~1 ~ ~ ‘g ,0 ,, ,2 ,3 iCONNITTIEF(HAERONAVTICS

I

J

Figure 29. - Variationofresultantair-streamtwistwith advanoe~i~eter ratio. Wr-Stream twietbaeed on geometrio helix angle with assumption of no body interference. )

‘%1l--m.

z0.

— —.

NACA ARR No. L6E22

4

2

0

-2

4

2

0

-f?

(a) Propeller 30S;

Fig. 30a, b

\

\ /

J 8 3.8.

, 1

COMMITTEEFORAERONAUTICS

-40 z 4 6 & ;0

x(b) Propeller45S; S sCM.

Figure 30. - Vai?lationof geometric angle of attack, based on chord line.

‘0.75R- ‘“0075R=Oo.

Fig. 31a, b NACA ARR No. L6E22

Przpe5//&-

45J’—— —308 ------------

(a) Rotational-inomento.m-loss faotor.

,0/6

,0/2 &‘~

.O&

NATIONAL ADVISORYCOMMITTIEFOMAERONAUTICS

‘.2 .3 .4 .5 ~.6.7.&.9’10

(b)Axial-momentum-lose factor.

Figure 31. - Dletrlbutlon of Induced -WY lo-es in climb. CP = c’.246 J = p.00.

NACA ARR No. L6E22 Fig. 32a

,004

,003

.00/

o

P/-ope//@-55s45s3as ——— ———— —

0“ ,2 .4 ,6 a /’ox

NATIONAL ADVISORY

COMMITTEE FM AERONAUTICS

(a) Axial-momentum-loss factor.

Figure 32.- Dietrlbution of induced energy losses at high speed.

Cp = 0.246; J = 3.15.

I —.._.—., ....-....—-... —..—-

Fig . 32b NACA ARR No. L6E22

.008L iIII Ehope#er

.007 ! 55sI 45s ———

30s ––––– -_Ii

.006 I 1 I+ ~Pinner Sut fa ce

IIi

.005 1IIII

● 004\

dc@x

.003

.W2 -\,\

4\ /c \.\ / \\ \ /

.001 \ . / \-- ___ //

\NATIONAL ADVISORY.,

COMMITTEE FORAERONAUTICSo

0 .2 .4 ~ ,6 .8 /.0

(b) Rotational-momentum-loss factor.

Figure 32.- Concluded.

-:.:

x NATIONAL ADVISORY

COMMITTEEF~ AERONAUTICS

zo.

Figure 33.- Distributionof fractionalenergy loss due to profile drag. Take off. Cp = 0.080;J = 0“8°= ~m.

E’jPzqoe//er F

55s a 04Z455 —— .037

e= J’@h)er suPf (7C& 30s –––-– .044

/ ‘\/’ 1,

/ \f \

/ \b I

,a$f AT

duf//,

Ok/ /0 I

9 !LU2

___ ---NATIONAL ADVISORY

COMMITTEEF~ AERONAUTICS \

10 I

.2 .3 .+ .5 .6 .7 .8 .9 lox

o.

Figure 34.- Distribution of fractional ener&y loss due to profile drag. Climb. Cp= 0.245; J= 2.000 :

NN

@Propeller P

55s 0.05/45.5 —— .(?4930s -----.- .050

Jp/hhep SuPfuc e

\,

(I-7:)* <

.W2 — -— — — - ~ — — — — — —‘. —-

COMMITTEEFORAERONAUTICS

o.2 .3 .+ .J .6 .7 .& .9 /(7

x

Fi~~re 35.- .Distributlonof fractionalener~ 10SS due to profile drag. High speed.

Cp = 0.246; J = 3.15.

zo.

rm

%r.

m.

wc-n

‘y/-

1

1.

Propeller55s455 — —

E+

0.03$.Q4i

“ .2 .3 .4 .6

Fl,gure36.- Distribution of fractional

.6 .7 .8x

ener~ 10s6 due to profile drag.Cp = 0.400; J = 3.00.

.~ 10

High speed.

.—

-1- 1 z\ >

\ E- E\ Prope//er 7 E

.0/0 \ ‘!, Sss am “45s —— .dw g

\ \+\!f#Av78P

30~ -------- .070 .

su~foc e K

,Om \ Eli m

\,OA!$ \

A(/-~’)~+ \\

‘. \. // \\

.004

a? “ F

NATIONAL ADVISORY/

\

COMMITTEEFORAERONAUTS

oI I

.2 .3 .9 .5 .6’ .7 .(9 .9 Lo w

Figure 37.- Distributionof fractionalener~ loss due to profile drag. High speed.Cp = 0.320; J = 3.80.

I

Fig. 38 NACA ARR No. L6E22

.7

,6

,5

.4

CL

.3

,2

o

H+H-H ‘%’TH-tt-bK ‘o’‘------Ir

t

, ,I

I

hu

NATIONAL ADVISORY

COMMITTEE F~ AERONAUTICS

o .2’ .4 .6 .C9 Lox

Figure 38.- Variation of CL with x at take-off.

Cp = 0.080; J = 0.80.

llACA ARR No. L6E22 Fig. 39

.7

,6

,5

,4

CL

.3

.2

./

o

Prope//er

45s —30s ---------

\

COMMITTEE FOR AERONAUTICS

.2’ .4 .6 ,8 /.0x

Figure s9. - VarLation of CL with X at climb.

Cp = 0.246; J = 2.00.

/

I

Fig. 40 NACA ARR No. L6E22

.5

.4

.3

CL

,2

./

o0 .2 ,4 .6 .8 Lo

x

Figure 4).- Variation of CL with x at high speed.

Cp = 0.246; J = 3.15.

Prope//w55s45s,305 –––––––

k\\

—

COMMITTEE FOR AERONAUTICS

—

NACA ARll”No. L6E22

.7

,6

.5

.4

.3

CL

.2

,/

o0

Fig. 41

.4 .6 .8x

F@re Q.- Variation of CL ~th x athigh speed. CP .0.320; J.3,&)*

.

---- .s--

.

., .-

0

.

Illlllllllililliilil3 11760’

! H CENTE

Ilhlllllllli3544029

—1—m Ilm—ml—m-11