: , sz6s7ol

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

ltrltRTIMl: RI:P()RTORIGINALLY ISSUED

May.].942as_oz'az_um Report

TEST OF NACA 66,'2--116,a = 0.6 AII:]FOTI.,SEOTION FITI_D

WITH PHES_ BALANCE AND S_ FLAPS FOR

THE _ OF _ XP-63 AIRPLANE

By William J. Underwoo& _ Frank T. Abbott, Jr.

:f.,azzg.l.eT'Memorial Aeronautical LaboratoryLangley Fie]/, Va.

F _L E-'ZCOPYC i_- Tobf_rotu:_dtO

• , .... for A_r{_autu_• i,_ o" , ','_

'"'::i:iiiii!iii_iiiiiii!ii!ii:::"'"::;Si::'"

WASHINGTON

NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution ofadvance research resu/ts 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. All have been reproduced without change in order to expedite general distribution.

L - 701

https://ntrs.nasa.gov/search.jsp?R=19930092767 2019-03-26T13:01:08+00:00Z

NATIONAL ADVISORY C01_9[ITTEEFOR }{__um:.u.L_,<,o_v_'............

_,J_I.!DRANDU_.{REPORT

for

Army Air Forces, i_,[aterielCo_m_mnd

TEST OF NACA 66_2-116, a - 0.6 _ _'" ..... ,:-,-,_

WITH PREoSUZc_ BALANCED AND SLOTTED FLAPS FOR

Th_ WING OF T>Z XP-63 _.IR_L_f_

By V_il!iam J. Undem,'ood and Frank T. Abbott, Jr.

INTRODUCTION

At the request of the Army Air Forces, 7_{aterie].Command, testshave been made in the Langley two-dimensional io_:-turbulemce pressure

tunnel of a model of 'the NACA 66,2-i16, a = 0,6 airfoil sectionrepresenting the root section of the wing for the XP-63 airplane.

The data presented in this report consist of .t.hefollo_ing:

(a) Lift, drag, and flap hinge-moment characteristics forthe internal, balanced flap.

(b) Lm_t, o,rag, "- "_" _ ano_ flap hinge-moment_ characteristics forthe "modified" internal "..... _o_:,.Lance flap.

(c) Lift and drag Qharacteristics for the slotted flap.

The model was of 2h-inch chord (c_-), built of wood With dural

slot cover plates for the flap. All flaps were equipped withpressure orifices. . .

METHOD I

Lift and drag measurements were made by methods described inreference I.

The flap hinge moments were obtained from pressure-distributionmeasurements by .integrating the normal and chord_ise pressure-distribution diagrams, the pressures being ploi,ted against theorifice projections on the flap chord line and a line perpendicularto the chord line.

TESTS AN]) ._tESULTS

_ < .u_.z%,,drag) and pressureInternal balance £1aD (of = 0.Io67%r),-_

distributions over the _la_b .Lul___ _ ' _ .sea._a, were made on the model at(_,_J.te ,_t_.(.=_o 0° , ,various angles of attack (_) for :._'1_"_._.._-' _-_ _'_ (5£) of .I0°

and :fao The japs betvreen the flaps and slot covers20°, 30°, hO°, ..,_,. ..in original _ > "_:'""_' . " I -the ,.cn.ci_t, lo -t we]?e measured and _.ou.no, to be Oo0013c wtop and O.oOp2c_, T bottom. The results of theso tests are presentedin figures i, 2, 7, and 8,

1

At the time ±.his report was originally published, some of thecorrections, r..(.J.:..,.J._"_'__P._,..,_for z'e',_.uciz_, the test data tc free-air conditionshad not been ,'-__"-_ " ,ed,.t_rm_In.,d.The values of section lift coefficient C_(figs° 3 to [!and fi.._,,_,_-,I].to 16) should be corrected by the follow-ing equation

( /

c_. ::0.)o5c t + K(correci:ed)

Where the values of K are obtained frora the :following f,a.b]e:

_-T • i̧ . t , , , _ _ ,, i ±, , ,w

Flap deflection

5f K

(deg)

0 O,003I0 ,.006

l_; .oo?20 .0193o .Ol8_o .P3o

O tk5 • _"50 .026

3

: The •tests were reoehted-for flap deflect'ions of 15° arid h5° v.d.th

the gap on. the uP]?br S_irface cm].arged to o:.oo_2_hv,the lo_,rerremaining

the. same. Thee resuilts are presenbedin {:'%"_rres.3and:_b aridtables I and If.

The tests were again i-'eDeatedfor flap _ .,,7,,_._ -o -,oand hh0 _ith the same gaps and the pressure se_l].(c_irtaih) removed.

These results are presented in figures; _ and _', and 'bab].e!..

"Modified" internal. balhnc:-4flap (cf = O.1667Cw).-Lif'h, drag,

and pressure distribubions over the fla_,,,'-_-f:.d.].y,_a3e,-l._,_.,,_,were made atvarious angles of attack for ,.]._pdeflections of D° ioo 20o., 0,qohO°_ and 50 ° . The results of these tests are presented in figures

7, 8, 9, and IO.

Slotted flap (cf : O.2_O5%_).- Lift r_n::],drag data were obtained

at flap deflections of O°, 3._o and [i_ ° with the slob cover plates inthree different slot conditions designsbed in the sketches on figure'3 ].3.,

12, and 13 as conditi.ons_l_ 2_ and -_3_ respectively. The flap hingepoint :;{aslocated in three dilferent posfLtions _O_ each slot condition,except condition 3, and designated as upper_ midd].e_ and bottom(figs. II, 12_ arid 3,.3) The le_ul_,_ of these tests are p_...._en_,edin figures 1]._12, 13, lk, !5, and 3.6.

: T'_°C,:o"_ "_TJ io JAJS.i.Oi_:

t

Internal. balance _'- ) Th_::_section hinge-moment coefz_clerits in

fi_.ire I .for the .origins.1 [[aj@Sa.nd in t?!!_fully se'::,.ledcondition :intable I for the O.OO5"2('..._,ap_::do _{o% include i_heh_h<e mom,3nt.sfrom

_,c.,o ..... the sea].in_ curbain'. Figure 2 andthe pressure difference _ "_.....'table _Tt re,_pe_,c+"_._i _e-_..3--_i,give the pressu.rc--c,:)e_: l_,.Lent"'-' _" --'. " - ,_._._./_-_-_'_-_:_r,_,_.__.,.,._.._:,,_ acrossthe curtain from vd_ich it is possible to :,_a]_cu].atethe ba].aricing.effect of "the curtain.

Comparing the fu]._y'"',sea._c,u__" __ 0ondition with O.O052c_._gap (table I)"o it _n be seen tn_t :forwith the origins], gap configuration (.,.i_,.I),

' '-e ,, _,mY9_ gaps werea flap deflection of 15°_ the h_¢.<_,moments fcr the .O.o._....w .

larger ,than for the •original gaps; however, f6r a !'!ap deflection of2 o!_5° there was very little chancre in the h!n;_'e momeJ£s. This '_

probably due to the fact that at the small f:{s__deflections thesensitivityof the flap to small internal _,-:__-e chan_?_esis better

than at large flap deflections where the flap is stalled.

Table I shows the hin;ze moment, for the flap at an angle of

at%ack of .3.0° to be larger for the sealed condition than for theno-seal condition. This is due to the internal, pressure which is in

h

such a direction as to increase the hinge moment rather .than decrease

it s as showl in table II. This pressure reversal is possibly due tothe combination of a peak pressure on the flap at the hinge and thelarge gaps. A comparison of the hinge moments for the two conditionsin table I at a flap deflection of h5O where the flap is stalledshows the internal balance to be counterbalancing about one-third of

the unbalance moment. Although the gaps are different, a furthercomparison at a flap deflection of IO° bet_veen figure ! and the no-seal condition in table I shows the internal balance to be more

effective when the flap is not sta]led.

It can be seen from comparing figures 3 and 5 with the originalconfiguration for the internal balance flap in figure 7 that themaximum lift is little affected either by small changes in the gapbet_veen the slot covers and flap, or by removing the sealing curtain.

Comparing figure 3 with figure 5 it can be seen that the lifts forthe sealed and no-seal conditions, at a flap deflection of OO with

O.O0_2c w gaps, are about the same_ however, for the no-seal conditionat a flap deflection of h5 ° the maximum lift is slightly higher thanfor the sealed condition.

Comparing the fully sealed cor_figuration having 0.0052c_v gaps(fig. h) with the original configuration for the internal balanceflap (fig. 8) sho_Ts that at a flap deflection of i'_° in the low-_rag

range, a small decrease in profile drag resulted from increasing thegap on the upper surface to 0.0052c%v, Comparing the no-seal condition(fig. 6) with the original internal balance flap (fig. 8) showsthat at a flap deflection of I0 ° a marked increase in the dragresulted from flovr through the gaps.

: "_,_odified"internal balance flap.- The section hinge-mpmentcoefficients for _bhe i'mo_iSied".]_lap-(fig. 9) do not include the hinge

moments from the pressure difference across the sealing curtain._ Figure IO gives the pressure-coefficient difference across the seal-

ing curtain from which it is ]_ossJb!e to calculate the balancingeffect of the curtain. Comparing the section hinge-moment coefficients

'hfor the "modified" flap (fig. 9) v,_th L._e ori_t'inalconfiguration,...._,for the internal balance flap (fig. l) sho_vs the internal balanceflap to have slightly lower hinge moments.

The lift characteristics of the model with either the internal

balance flap or the "modified" flap are about the same (fig. 7).

The profile drag at a flap deflection of iO° _th the "modified"flap is slightly higher than for the internal balance flap in thelovr-<Iragrange, as shown in figure 8.

5

Slotted flap.-A comparison of figures II 3 ].2, and 13 showsthat the highest maximwn lift coefficients are obtained in each con-dition with the flap o_e_:_ecoeclI.o in the bottom hinge location.With this hinge location, condition I gave a maximmm lift coefficientof about 2._2 (fig. !I). Removal of part of the bottom slot coverplate, condition 3, resulted in only a slight increase in the m_<im_unlift coefficient (fig. 13). In condition 2, the bottom slot coverplate removed and the slot faired smooth, a value of abo_.r_2.76 ;_ss

obtained (fic. 12). Lift characteristics a.t 5f = 0° _vere practicallythe same for all slot conditions,

Drag coefficients were obtained for all three slot conditions"_" _'_ _'__ _4, !>, andat hinge, locations and .,.lapc_.....l._ct._ons,shov_Tlin fixtures l, _

16. The values of the drag coefficients were uncertain in .-"na:vofthe conditions tested, possibly d'..leto localized spam_:ise separationor spam._,iseflow in the slot. An attempt _m,s ,_s..,._dein condition 2,5f = O°j to prevent this spanvd.se flo_/ by putting several thin dsmsin the bottom of the slot on either side of the region _:¢heremeasure-

doub __,.u._."_ ....ments were taken, but it is *_" 5na_ this stopped all the crossflo_ar. The uncertain parts of the drag cu_#es are drav._n_;ith dash

lines (figs. lh, _.;Ic,and 16). These should be considered forqualitative purposes on.ly_ Figures ![_.,15, and !6 sho_a_that a _zrked

increase in minimum drag occurs in Qondit.ion 2 at 5_ = o°, becauseof-the open slot- on ,_he].o_,_rsurf_ce. ._ve_._"ith slot _,a.__._.,....,closed in condition 5, there was still a slight increase in drag.

It is apparent for good flap characteristics that the slottedflap be designed to include a door to cover the slot in the retractedposition for low drag and to deflect about the bottom hinge locationwith the slot onen_ for maximum_ l,_.t."_

Cqm_orlSO n of.flaps. Althou_ _m.5her maxm.mum Im_t co.,ff_.c_,nt_are o_Jtainabie _d]:[fhlt]i_ slotted flap tested than with the. plain flap,

•_ _ " o].ottea __'_;-'comparat.__e.._y].itt].egain is shoran by bhe .- _ '.:._.c_.,Ira,Less a IOW

flap hinge point is used. A door is also requ:]red for i.he slotted.... ... .. 49flap if high maximmm lift coe_'_'-tcients,_lap deflected_ a_x[ lov_-drag

coefficients, flap neutral, are both to be realize£. It alt>o appearsthat the plain flap offers some advantages over the s!.ob%ed flap testedin extending the low-drag range to higher ]ift o_ef.__._!ent,_,when thegap is f_.l!lysealed (fi{, h).

Even if the mechanical complications of the s].otted flap withdoor and low hinge location are acceptable, some danger exists ofinducing tip stalling of the :_.d.n_by the use of a powerful flap.This effect has been shov_, to occur on tests of a model of a some_vhat

6

similar airplane in the NACA 19-foot pressure tunnel, it is thereforereco_neneed, that the plain flap, fu].!_!sealed, be used .for the XP--63airpl_ne if the maximum lift coefficients ohta_.ned _:_iththis flapare acceptable.

_le_-_[emoria! Aeronautical T _ _ _,..... 5 _- _aoc rauoI_

National Advisory Committee for Aeronautics,

Langley Field, Va_ ]'_.y23, 19h2.

REFEP_NCE

• Abbott Ira H. and Davidson. },4i]ton:• I. Jacobs, _.,as_manN._ , , ." _ " _n-"_. _._._J1_-,,_m_=_si.sat LargePreliminal'v Lo_:-Dra_-A!r_oll Flap Date.....

a_m. Low Turbulence.. l%_IZA.<(,R,!_b.rchReynolds N_mbers y _ _,,_- ]oho_.j _4-c...

L-701

TABLE I

Hinge-Moment Coefficients on 0.1667 cw Internal Balance Flap on a NACA b6,2-i16

a = 0.6 Airfoil Section at a Reynolds Number of 6,000,000

Angle of Attack (_) }.0 ° 4..1° 8_I° 12.2° 16_2c ! =h _I° i

_}_odel Conflg_a_zon Section hlnge-moment coefflclent, _h !

i_lly sealed 8f = 0 _-0,025 il 1i o°o052% _- i -o.12_-o.Ih5-o_155 _ooo53i

bottom _,_i_ Of = _5_ _O._8 _0_4 i -0o3_7 ®0.3_6 -0_12 _0_.98 _0_ I

INo seal _f = 0.005 _0_013 _0.018 _0®050 =0_i05 i_0_i_2__ <_0_O20

0_0052 c_ _p- _f = !0 _0,:_ _0_9 -0.i_5 -0.162 -0.190

I bottomt°Pand 8f = _45_"-0.h88....... i_0._ -O.h_ -0._70 -0o_66 i , -0._4_}4I I

* Hinge-moments from curtain not included.NAIIONALADVISORY

COMMIT'lEEFORAERONAUTICS

TABLE II

Pressure Differeoce Across Curtain for a NACA bb,2-11b a = 0.6 Airfoil Section

With an Internal Balance 0.1667 cw flap, 0.0052 cw gap-top and bottom

fully sealed; Reynolds number of 6,000_000

Annie of Attack (_) 0 ! 2.00 I }.0 o ,i _.i ° 8"1° 12"2° i 16"2°_J i "_'iO

..... Confi_u_a_lon Pressure coefficient difference across curtain, 8U - SL!D

_..1_ seale_i Of : 0 _ -0.009 { " i

_.,_......cw gap- 8f : 15 i0.671 0.63[_ i0.625 i 0.625 _ 0.862 i 0.752

6 = _ _1.196 1,223 1,251 i 1.251 I 1.196 i 1,776 i 1,006. _ L_2 _ !DOt ...... . i

NAIiONALADVISORYCOMMFI]EEFORAERONAUIICS

L-701

NA11ONALADVISORY _ ,NAI"IONALADVISORY

COMMITTEEFORAERONAUTICS COMM!TIEE*FORAERONAUTIcs

2.0

/.6 -......._ i ' ll f I/E _>

i _i ....i_- .oze l ' "

,.2--t........! ,[

t t iL- , .o/2 ' ! i

l ....... I l--l] ..... Flap an_le,ocf,deg 5gmbol _ I

-/6 -8 0 a 16 ,24 I_n.qle of altack,oc_ de_

O-- i:_ -14 0 .,_ .8 L2 L_

_ecf/on h'_f ¢oefficient_ 9

FiEure 3 -- .Lift Ker#ua angle of _tttack For _ NA_l_ Figure 4 _ l_if_ veroua drag for a NACA 66}ZNI6 a.0.666)2-116 6=0.6 wifh =11 in_el"rl_l balan_ l wi_ or)in_er'nal balance 0.16_70_, flap_O.O0_Z¢_0.1667c w Flczp_ O.;OOS,'°cw _ap._-_op =ug_ ' , gap-_.op an¢_ bof._or_ , fc,ll_ sealed_-bo_om_ Fully ,se,',le¢_; ,_e_/_o/d_ n,_r_bl/" ,_=wnold_ _,,rnl_er" oF 6_000_000.e_ 6_000_000.

IOL-q

•000_000_9 ./o

•000_000_9 go .a_c/u_nu _plouB_¢ _.p,_AQuaa._ ._qu_nu SplOUR_w !paAou4ed /_a_ a._nssa.ddlOa_" _.4_s_a,/dtuao:l_oo/pu_ do;-doB _o __qO0"O °_o_oq pu_ doF-doB _ __-qO0"O'd_lJ _ f.9_l'O

_d_lj '_ L_,O/"0 a_/_q /o_aa_t _ qZ,t_ =_UOl,Oq iDu.4a_u! uu .q}/,,_ Q.O=_O 91/-Z_9

97 _'1 ._" 17" 0 _ = .9"-

• 17_I ; , , _ _, o/ _ = =, ' ' I I /o_B_ ,,ainu,, i .-.

' ' "C"_- ,'l _/ _o

.l;,,.J"

o 0 _.iq_,,B,e-_w '_y"alBu_ d_l--,-'

souav,ou:_v,_ :mu_oo _t_._.v_ou]vuo4:]:mt_ooAI_O$1AK3V"IVNOILVN :_lJOSl_eV "tVNOIIVN

o 000¢000c9 Jo ../aClU4nu ,.¢7_1oc4_ac_

• 000¢000*_ Jo ./aqu4nd S-_lOUtiae/ 9.0.z_ ( 911-_c99 _3_lV o ._o_ .y_z_}_z_ _1o _16u_ _,n$,da/ _./7- /:, a.4nB/..,_l

_'_' _I _ 0 _- _I-

•: _ I_ "_ua,=,,_ao_.._i/ ¢4_;=_o_ . I "" IP*I-

I - < : _ _._ --oz. _ _ _> ---0/ I I_'- _× o --o ' I 'i "-"

(3

V

i_ ,_:, , _. i_t:j_I/i//_ ....._"

_,.-- ! I'c_,///_ I I I = 0" "

i

1_- _ .... 0_' { , ,_.._,"q l> O/x ..o -- -0 _IOIIflYN_Fi¥llOJ:]:]lll_l_unn ! J

"00_000_ jo "d_qv_

•000_000'9 Jo .aaq_nu. _plOUl_ac7 m _ _,pagipo_V,_oZ991"0 _ _/2/_ 9.0== o 911__,99b_OL_/V

"_DL991"O _ q_l_ , ,9"0 "_ " 911-_'99 _'D_'N

_ 0.¢ 0_" - O_ Oz /-JO/ 0

0,.C" 0_;" O_ O_.'? O 0 " [_;-" I I i I Q

i , :3_' --- Z'Zl , "_ < I i I+'-_._---r'_ o _- ,v .... I'S_ i ' _

+ .... o'_- !: I I Z"_ I "_ '.-:-\_ ! _ _:

o....,_-. , , , /IY ° i i_ .__. ! "-, ! , i\Xl\"_ _ _ , ,

I fi

j/ : :/_,_Qtq'7.,DNt .ION ',-+P--)

/'_ _-''._q _ _ _ ..... _'91 NIW:.LaDD I/WO_...4g'iP,_t/-,ioL/,, _9,NI H "-3_0_I

' i "> ..... _"_/

_" I / _/_ _..... _._

'_A "_ / l I--T-,, ' ,_..... /_

I K I i ' _ _" ,:>,..... o'_"

, , + ..... 0"_-

o ...... /_;'-

I ,/ i i i ,,<-SOlINVNOtt_iVltOJ ]?IilNNOO

AttO_IflOV"I_liOl.i.VN

TOL-q

Bell Aircraft Corporation Model

X2-63 wing, NACA 66,2-116 a = "0.6

section

2_-Inch chord model with slotted flap

Test no. TDT 203

E = 6 × lO 6 -(approx.)

Bell Aircraft Corporation Model

XP-63 wing, NACA 66,2-i16 a : 0.6

section• <

24-inch chord model with slotted flapd

Test no. TDT 203

R = 6 × 106 (approx.)

No. 3 Condition: Partial bottom slot cover

plate on (5/8-inch shorter than

original). Original top cover

plate on.

Flap angle Hinge location

2.8 O 8f = 0° Upper

A 18f = 15° do

k v 8f = 45° cl.of _ Gf = 45 ° Bottom

i 2.4

_ NATIONAL ADVISORY

l OBMM_TT_ KQ_ A_@NA_

if2.0 i i

1.# 1 ,

o/ l \I_.,_ \

_ / / /,xZI / 'o 2 11I I./

// 'I

. / .......... l

t ,

-2L_ - 8 z6Angle of attack , m (deN)

--- St,,:0 °, ,.S'/o,_ Co_,_,>?;o._

_/_ / "--I. ,. .I Loc_,'t,'_n.s- j _ .77",_,2.t.iip ---

4Pigurel}.- Lift characteristics ith partial bottom cover plate on (original top plate on).

Bell Aircraft Corporation Model

XP-63 wing, NACA 66,2-116 a = 0.6 section

24-1neh chord model with slotted flap

Test no. TDT 203

• R = 6 x lO6 (approx.)

No. 1 Condition: Original top and bottom slot

cover plates on

Flap angle Hinge location

O 6f _ 0° Upper

O _ 6f = 15° doG 6f = 15 ° Middle

_-_ × 6f = 15 ° Bottom

NATIONAL ADVISORY

COhtMI_TEEFORAIRONAUTICS

Figure_.- Drag characteristics with original top and bottom slot cover plates on.

Bell Aircraft Corporation. Mode!

XP-63 wing, NACA 66,2-116 a = 0.6 section

24-inch chord model with slotted flap

Test no. TDT 203

R = 6 x 106 (approx.)

No. 2 Condition: Bottom slot cover plat e off (Original

top plate on.)

Flap angle Hinge locationo 6f = 0° Upper I

Of = 15° do (_Q 8f = 15 0 Middle _,J

.o36 F Ir

I .o32 /' .028

•02Lt

o7.020

,- /_ /!

o //

o k / I"0 , I:

\ Z.012 -.

_ o .r,

m _!

I

.ooh

-1.6 -1.2 %8 _LL 0 .LI .8 1.2 1.6 2.0 • 2._I

Section lift coefficient, oi,

Figure l5.- Drag characteristics with bottom slot cover plate off

(original top plate on.)

Bell Aircraft Corporation Model

NATIONALADVISORY XP-63 wing, NACA 66,2-116 a = 0.6 section

COMMITTEEFO2AEEONAUTIOS 24-1rich chord model with slotted flap

Test no. TDT 203

R = 6 × .106 (approx.)

No. 3 Condition: Partial bottom slot cover plate

r-_ on (5/8-inch shorter than original. )

O Original top cover plate on.t-| Flap angle Hinge location

_-_ o _f = 0° Upper

•a 6f = 15° do