1、.RB No. WX)2(If, - , .,.(,“-).4 *“-NATIONAL ADVISORY cOMMlmE FOR AERONAUTICwilmm IuwolrrORKWALLY ISSWDDecenber 1943 asRestricted Bulletin 3L02 .PROPOSAL FOR A PROPELLER SIDE-FCIRCEFACIWRBy Herbert S. R$tmerLangley Memorial Aeronautical LaboratoryLangley Field, Va. .WASHINGTONNACA WARTDLIEREPORTS are
2、reprintsofpapersoriginallyissuedtaproviderapiddistributionofadvanceresesmhresultstoanauthorizedgrouprequiringthemforthewareffort.Theywerepre-viouslyheldunderasecuritystatusbutarenowunckssified.Someofthesereportswerenottech-nicallyedited.Allhavebeenreproducedwithoutchangeinordertoexpeditegeneraldistr
3、ibution.,IL- 336Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.3 1176013542692 !NATIONAL ADVISORY COMif15!KEEFORR3LSTRICT31D BULLETINAERONAUTICSPROPOSA% l?OR A PROPELLER SIDE-FORCE FACTORBy Herbert S. RihnerSUMMARYfKnowledge of the side force on a
4、proeller in yaw -the fin effect - is ueful in the design of tail sur-faces , in the testing of pawerecl.aircraft models, and iiq iornal. stability and control analyses. A side-forcefactr coinputed from the plan form and pitch distribution in shown to Oe a good index of the relative effec-tiveness, N
5、er blade, of yaved propeller in developingside force. By the general use of sideforce factors,existing charts of prpeller side force may be simplyextrajolated to”give Me side force on any specifiedpropeller in any specified operating condition. Thesugestion is made that propeller manufacturers andde
6、signers present the stale-force factor with the activ-ity factor as a fundamental parameter for all bladedesigns and that reports of testsof powered models invrind tunnels include the sioo sind (): (1)0.2side-force factorblade sectiou chord at any radius rpzoyeller diameterblade angle at radius r(.0
7、when 13= 2a at.:. 4. :/0175R and p/Dtan=)m :,radius to tipeometric pitch at radius rThis side-force factor expresses the relative effective-ness, per blade, of a propeller in developing side forcein yaw or “noraal for ce in qitch and nay be used in comparing these characteristics of propellers. It i
8、s seento-3e similar to the activity factor I. .*Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3A.F. = 10;OO .;” + ($)3 ).i+liidhis intended to express the relative effectiveness,per blade, of a propeller in a%sorling power. .References 1 and 2 show
9、 that the side force on apropeller in yaw is approximately proportional to theprojected side area. There is a small correction foraspect ratio. Examination of equation (1) will showthat the proposed sideforce factor is directly proportioaal to the projected side area of one blade;l thecontant of pro
10、portinality is chosen to give a valueof the order .of the activity factor (6O to 140) as aconvenient magnitude. The sideforce factor is there-fore a suitable criterion for comparing propellers havi-ng the same number of blades.USE ,OF SIII this information has been used to prepare thecharts presente
11、d herein as figures 1 and 2. Figure 1gives the ratio of stale-force derivativesoyj/ for desired propellerCys$ for Hamilton Standard propeller 3155-6as a function of the side-force factor for the desiredpropeller; figure s22gives the ratio of side-force deriva-tivesCy$ for desired propeller1CY% for N
12、ACA propeller 1-3062045. .,. .,.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-5,./as a function of the side-force factor for the desiredpropeller. In both figures 1 and 2, the approximaterelation of equation (2) is plotted foq comparison.For a four
13、-%lade single-rotating propeller , for example,figure 1 may be applied as follows: The ratioEY$ for desired fourblade propellerCf SW for fourblade Hamilton Standard propeller 3155-6is thb ordinate on the fourllade curve corresponding tothe abscissa S.F.I?. for desired propeller.khb + curve for a spe
14、cified propeller may apply tothe angle to the zerolift chord; whereas P g-enerallyapplies to the angle to the reference chord. Hence, the.,label i3= 25 Pat 0.75R on.a given curve does notm/11necessarily mean that the formula tan P = n:wouldgive the same value of at 0.75R. Zither definitionwill resul
15、t in approximately the same sise-force factorprovidod that, by ths same definition, = 25 at0.75R. A suitable procedure is to select any availabloPcurve and to computes curve ofn P against r/R from “JJthe relation p/Dtan=Ffail to pass through 25 atcurve is obtained by addingvalues of the incrementr/R
16、 = 0.75.This curve will generallyr/R = 0.75. The desiredor subtracting from all thethat will make = 25 atThe fact that the Hamilton Standard propeller 51556has Clark Y blade sections and the NACA propellerZCX3062-045 hae” NACA 16serias blade sections is of somesignificance. The charts of Hamilton St
17、andal*d propeller3155-6 should be used as the basis of extrapolation forpropellers having Clark Y or EM? 6 blade sections, andthe charts of NACA propeller 10-306045 should be usedas the basis of extrapolation for propellers having NACA16-series sections. This restriction eliminates errorsof the orde
18、r of 5 percent.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. . . -. .-:. -6.The significance of the blade section lies in thedifference in angle “between the reference chord and thezerolift chord for the several sections. This differ-ence is of t
19、he order of 3 to 7for the Clark Y and1 to 20 for the NACA 16-seriesRAF 6 sections and l%sections. The zerolift chord is fundamental in theevaluation of side force but blad-setting designationsgenerally refer to the geometric reference chord. .Thisconvention was retained in the side-force charts of r
20、ef-ermce 2. The curve for Hamilton Standard propeller3155-6 designated P = 25 at 0.753 thus nay also ?)edesignated PO = 28.2 at 0.75R, where 130 is theblade angle tb the zerolift- chord; the correspondingcurvo for iiACA propeller 10-3062-045 may be designated,PC)= 26.8 zt 0.75R. For accuracy, theref
21、ore, comparisonshould be made of propellers for which the average dif-ferpnco “etweon and 130 is nearly tho same; that is,propollers with more orless similar llede sectionsshbuld be compared.- ILLUSl?RA.TIV3 EULiPLEiZs an:. illustrative check, the side-force factorwill be used to obtain a value of t
22、he side-force derivativo Cyrv for a specified two-blade propeller by extrapolation from the tvo-%lade chart of Eamilton Standardpropelle 315%6 given in reference 2. Yigure 14 ofreference 2 gives both calculated and eerimental valuesof Cylv for the two-blade propeller of reference 3.Bladeform curves
23、for this propeller are given with cor-responding curves for tho Eamilton Standard propeller3155-6 in figure 3. The popeller of reference .3lacksthe spinner of Hamilton Standard propeller 3155-6, but “ “computations show that the shank bled-e sections provideenough aditi.onal area inboard of 0.2R to
24、compcnsatovery nearly.Given:TJIe two-blade propeller of reference 3 (data infig. 3)Roquiroi:a711. .,.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-7To determine CY$ , for P = 20.6 at 0.75R andthe advanc-diameter ratio V/nD = 0.6, by extrayolation f
25、ron tho two-blade chart of Cy$ for HaniltonStandard propeller 3155-6 in figure 5 of reference 2.Procedure: .1:1. ComTuto the sideforce factor for the propollerO 1)of reference 3 from its and $-curves in figure 3,D!Jlheresult is 74.6.2. Yrcm figure 1 read the value ofCy* for desired propellercj for H
26、amilton Standard propeller 3155-6corresponding to the abscissa 74.6. This value 3.s0.927,3. From figure 5 of reference 2 read the vale ofCytw corresponding to V/nD = 0.6 and = 26.6 byinterpolation between the 20 and 25 curves . This Vallleis 0.115. ,4* Uultiply the two values found in steps 2 and 3
27、-that is, multiply 0.927 3T 0.115. The result is 0.1G7,which is the value of Cylw for the propeller of refer-ence 3 obtained by extrapolation.5. As a check, from figure 14 of reference 2 readthe value of Cy 1$ on the = 20,6 curve correspond-ing to V/nD = 0.6. This result is 0.104, which is thevalue
28、of Cyl$ for the propeller of reference 3 obtainedby direct computation.A aumher of other values of Cyl$ for the propellercf reference 3 o%taineit by extrapolation are presentedin table I. The values of Cyl$ obtained by directcomputation, as plotted in figure 14 of reference 2, are:T-?Provided by IHS
29、Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-8included for comparison= Note that the propeller ofreference 3 has a noticeably smaller blade area thanHamilton Standard propeller 31556 (see fig. 3) %utthat the values of sid-force factor are nearly thesane, The aee
30、ment of the extrapolated values withthe Cornputed values indicates that the side-force fac-tor is a sui?ia31e criterion of propeller side force.The errors introduced by the extrapolation de-scribed herein will generally be sufficiently small tobe negligible in comparison with the A1O percentaverage
31、discrepancy between the computed sidforce ,charts of reference 2 and the afailable experimentaldata. Additional errors of the order of 5 percent maybe introduced, however , if the restrictions againstextrapolating for propellers with NACA 16-series sections fron side-f oce, charts for propellers wit
32、h ClarkY sections, a vice versa, are not adhered to.CON CLU13HIG REilARKSA side-force factor computed from the propellerplan fern and pitch distribution is shown to be a goodindex of the relative effectivonoss , per blade, of ayawed proyeller in developing side force. An exteneiveseries of side-forc
33、e charts for two repro sentative pro-pellers are available in reference 2. By the generaluso of side-force factors, these charts could be made.to serve for all convontianal propeller designs to pro-vide the propoller side-force data needed in the designof tail surfaces , in the testing of powered ai
34、rcraftmodels, and in formal stability and control analyses.It is accGi- suggosted that propoller manufacturers .and dcsignors present the sidforce factor with theactivity factor as a fundamental parameter fer all bladedesigns. It is further suggested that reports of testsof powerod models in wind tu
35、nnels include the side-forcefactor for the propeller used.Langley i;enorial Aeronautical Laboratory,National Advisory Commit tee for Aeronautics,Langley Yield, Va. . .- 7 .-. t J . . . . . . . . -.+ . ;. . . . . , .,. . . . . .:-.: , ; =.: .-.2:- . : , , .:. ., -:”.”; ,. ,”.:-. -,- .,. :,. :.”. .4 .
36、-. ,;-,.,.-*:.-, -,.,.,.,-: ,.-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-RI!FERENOMS1. Ribner, Eerbert S.: Propellers in Yaw, NAoA ARR.0 No a71m 3L09, 1943.“A 2. Ribner, Herbert S.: Bormulas for Propellers in Yawand Che,rts of tho Side-Force De
37、rivative. NAcAARR No. 33!19, 1943.3. Lesley, E. P., Worley, George Ii., and Uoy, Stanley:Air proPelers in Yaw. NACA Rep. No. 597, 1937.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10 USE OF THE SID3-FORCZ TACT OR IN OBTAINING THEmyl=! SiDE-FORCl!
38、DERIVAi IVE Cy$ = bY/i$,. mDai?Extrapolation made from curves of Hamilton Standardproyeller 3155-6 from fig. 5 of raference 2. Computed values froni fig. 1A of reference 2.J$ at0.75R(dog)16.620.62,628.60.2.5.8.3.61.0.4.81.2.61.01.4CyIw forHmi.ltonStandardpropellf3r3155-60.179.109.086.170.115.098.lFj
39、q.118.108.153.125.120(gYlw for propollerof reference 3,Computeddirectly0.169.095.080.150.lo.090.150.108.098.135.113.108Extrapolated(a)0.166.0945.080.158.1065.091.152.109.100142:117.111. .aSido-force factor for propeller of reference 3 is 74.6.Fron figure 1, for th a%scissa 74.6, read:cyfJ for desire
40、d propeller= 0.927(JY1$for Hamilton Standard propeller 3155-6 The values in column 5 are obtained by multiplying thecorresponding values in column 3 by 0.927. ,.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.iI,.-3.:6I I J/1/.;-,/ ,+/., .3I /./”/ “
41、.4. .P+T,i.3,., . . Qu -1.-. i /4 ,+ Y,/4ii,d: 1I Iblade,11II1111LkazL_-11 11 I11 II -1II 11 ! I I. .,“j yf for desirsd propellei?igurel.- Ratio of sideforcoderivative * as a functiof! 1 for Hamilton Stndardpropellor 3255-6of siia-forcofactor of dosircd prop/!.lor.11orextrapolationfrom sids-forcocha
42、rts for .1 Hamilton Standardpropeller 3156, for which side-forcofactor is 80.7. The approximattiratio y?i /S.T.l?.80.7 is includedfor conrparison.P.IIProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.,.,.,.:I,!q-, . .!1tI i.80 - 100 120” 140 lljo . ,
43、. , lF.3 a71 8 .5 a71 t7-. . -I,22-. I.-_l.-II I I _-i. - ,._ . . - L_,_*_. -J. _J.7 .8 .9 1.) yTigme 3.- Plan-forz, thicmess-r9tio, s.n:i bl.tie-angle-ti atrit.ution curves for Eamiltm :tandard .7.propell.w 7155-6 aud fm the pqwlkr of reforwce 3., iiU.-tiY; R, tip radius; r, stationradius; b, chord; h, thicess. MProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
