low-speed wind-tunnel tests of a full-scale m2-f2 lifting body model

8/13/2019 LOW-SPEED WIND-TUNNEL TESTS OF A FULL-SCALE M2-F2 LIFTING BODY MODEL

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LOW-SPEED WIND-TUNNELTESTS OF A FULL-SCALEM2-F2 LIFTING BODY MODELby Kenneth W. M o r t und B e d GumseAmes Reseurcb CenterMoffett Field, Cali$

NA TIO NA L AER ONA UTICS AN D SPACE ADM INISTRA TION WAS HINGTO N D. C. FEBRUARY 1 9 6 7

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64 asss-


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NASA TM X-1347

LOW-SPEED WIND-TUNNEL TESTS OF A FULL-SCALEM 2 - F 2 LIFTING BODY MODEL

By Kenneth W . Mort a n d Berl GamseAmes Rese arch CenterMoff ett Field, Calif.

GROUP 4Downgraded at 3 year intervals;decloxi f ied af ter 1 2 years

CLASS1F IED DOCUMENT-T ITL E UNCLASSI F I ED NOTICETh is material contains informat ion af fect ing the This document should not be returtied af ter i t hasnot ion al defense of the Uni ted States wi th in the sat isf ied your requirements. I t may be disposedmeon.ing of the espionage laws, T it le 18, U.S.C., of i n accordance w i t h your loca l secur i t y regu la-Secs. 793 and 794 the t ransmission or revelat ion t ions or the oppropriate prov isions of the Indus trialof whi ch in any manner to an unauthorized person Security Monual for Safe-Guarding Cl as si f ie dis prohibi ted by law. Informat on.

NATI ONAL AERONAUT ICs AND SPACE ADMlN STR A T ON


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OW-SPEED WIND-TLTNNEL TESTS OF A FULL-SCALF:

M2-F2 LIFTING BODY MODEL*By Kenneth W. Mort and B e rl GamseAmes Research Center

SUMMARY

The longi tud ina l and la te ra l - d i re c t io na l aerodynamic ch ar ac te r i s t ic s ofe W-F2 l i f t i n g body modelwere inves t iga ted i n th e Ames 40- by 80-Foot WindThe W-F2 co nfi gu rat io n w a s based o n the M2-Fl design with modifica-on s t o the a fte rbody, th e cont ro l sur faces , and th e canopy loca t io n . Thefe c t s o f modif ica t ions t o the model dur ing the t e s t series, bu t no t inco r -ed i n the f i n a l W-F2 Conf igura t ion , a re a l so inc luded .

The inves t iga t ion w a s conducted over a range of angles of a t t a c k fromt o +28O, angles of s i d e s l i p from -5O t o +loo, and free-stream dynamic17 t o g( l b / f t 2 .was l o n g i t u d i n a l l y s t a b l e o ve r t h e e n t i r e trimmed l i f t - c o e f f i c i e n t0 t o 0.9 . There was no evidence of s t a l l except a t24 angle of a t tac k and 10 ang le of s id e s l ip .l i f t - t o - d r a g r a t i o s rea l i zed f o r the W-F2 conf igura t ion were 4 .2

The re su l ts indicat ed t h a t th e M2-F2 conf igu-

The

INTRODUCTION

Stud ies o f l i f t i n g body r een t r y veh ic le s capable of con t r o l l ed g l id i ngl i g h t and convent iona l hor i zo nta l landings resu l te d i n the bas i c M2-Fl des ign( s ee r e f s . 1-7). The r e s u l t s of wind -tunne l and f l ig h t t e s t s of t h i s veh iclegu r a tion a r e r epor ted i n r ef e r ence 8, 9, and 10. The design of the con-r o l sur faces , th e a fte rbody, and the canopy w a s modified t o improve th e low-eed performance and handling c ha ra ct er is t i cs of th e vehic le and t o make th eration compatible with high-speed f l i g h t requirements . This modifiedw a s des igna ted the M2-F2. The low-speed aerodynamic character-s t i c s deter mined by f i l l - s c a l e wind- tunnel t e s t s o f t h i s modi fi ed de s ign andf f ec t s of o the r mod i fi c at ions t e s t ed during the inves t i ga t ion s l ead ing t o

e de f i ni t i on of t he M2-F2 conf i guratio n are repor ted here .

NOTATION

maximum span, 9.51- f tdr ag coe f f i c ien t ,

T i t l e , U n c l a s s i f i e dDq s


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CL1

CmCnCYDL2

qRnSU

'a

'rl

r

Ll i f t c o ef f i c ie n t ,rolling-moment coefficient,pitching-moment coefficient,

yawing -moment c o e f f i c i e n t, Ys ide - f o r ce coe f f i c ien t ,d rag force , lbl i f t f or ce , l br ef er en ce l e n g t h ( o r i g i n a l l e n g t h o f M2 , 20 f t

qs r o l l i n g momentqSbi t c h i n g momentqszawing moment

qSbs i d e f o r c eCIS

f ree-s tream dynamic pressure , lb /f t2x 2r ee - s t r eam ve loc i tyk inema t ic v i s cos i tyeyno Ids number,

re fe rence a rea (o r i g i na l body p lanform a rea of M 2 , 138.9 f t 2angle of at ta ck , angle between cone ax i s and f r e e stream, degangle of s id es l i p , deg

I Cd i f f e r e n t i a l u pper f l a p o r e levon def l ec t i on , deg I 4 4 r o i l 1 f + , GIlower f l a p def le cti on , degrudder def lection, degupper f l a p def l ec t i on , deg

S u p sc r p tr ad ius , in .The forces developed by the model were reso lve d along t he wind axes andt h e moments about t h e body a xes.The s ign convent ion fo r co nt ro l sur face de f lec t io ns , forc es , and anglesi s given i n f igu r e 1. Zero angle on a l l con t r o l su r f ace s i s def ined as t h a tpos i t ion where t he co nt ro l sur face i s tangent w it h t h e model surfaceimmediate ly upstream of th e c on tr ol hinge l in e .

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MODEL DESCRIPTION

The model i s shown i n f i g u r e 2 i n s t al l e d i n t h e 40- by 80-foot :iindtu nn el . The model dimensions a r e pre sen ted i n f i g u r e 3. The body of themodel forward of s ta t i o n 240 was made from a f i b e r g l a s s mold of a plywoodc o n s t r uc t i o n f l i g h t v e hi cl e (M2-Fl). D ev ia tio ns of t h a t f l i g h t v e h i c l e ' sd imens ions f rom those i n f ig ur e 3 were rep eat ed on th e model. The model con-s t r u c t i o n , t h e r e f o r e , i s ty pi ca l of la rge-sca le wind- tunnel models i n regardt o a i r l e akage , con t ro l sur f ace a t t achmen ts , and r i g id i t y bu t i s n o t t y p i c a li n r ega rd t o d imensional t o l e ran ces and sur face condi t ions . *ds fi0..-_____I___-_- c_. --.-I_ __

The co nt ro l system of th e M2-F2 config urati on ( f i g s . 1 and 3 ( a ) ) includeduppe r- su rf ace f l ap s tha t moved toge the r fo r l ong i tu d ina l con t r o l and d i f f e r e n -t i a l l y f o r l a t e r a l con t ro l , and lower-sur face f la ps th a t could be used inde-pendently or i n c o n ju n ct io n w i t h t h e u pp er f l a p s f o r l o n g i t u d i n a l c o n t r o l .The lower-surface f la p s were l i mi te d t o a m in im u m d e f l e c t i o n o f loo and werealways de fl ec te d to ge th er . The model had sp l i t f lap- type rudders on th e ou t-board su r faces of t h e ve r t i c a l s t ab i l i z e r wi th on ly one su r f ace de f l ec t in goutboard a t a t i m e f o r d i r e c t i o n a l c o n t ro l .

The devices inve s t ig a te d inc luded ( f i gs . 3(b) , 3 ( c ) , a n d 3 d ) ) t h eb o a t t a i l f a i r i n g ( which was incorporated i -nto th e f i n a l I42-F2 coEf ig ur at io n)elevons a t t h e b a se of t h e v e r t i c a l s t a b i l i z e r , f l a p s w it h t h e i r hinge l i n e a tt h e t r a i l i n g edge of th e af terbody, quasi-wings s imulat ing landing gear doors,ou tboard ven t r a l f i n s , and a c e n t r a l d o r s a l f i n .

TESTLNG PROCEDUREl

The aerodynamic character is t ics were obtained by varying the angle ofa t t ac k f rom -12' t o +280 fo r s e ve r a l con t ro l s e t t i ng s and f o r s id es l i p ang le sof - 5O, Oo, + 5 O , and +oo. The e f f e c t s of Reynolds nuniber were in ve st ig at ed a tone lo ng i tu di na l co nt ro l se t t in g and zero s i de s l i p f o r Reynolds numbers f rom2OX1O6 t o 3 106.w a s performed a t a Reynolds number of 3 6 x 1 0 ~ dynamic pressure of 97 l b / f t 2 ) .Unless otherwise noted on t h e f i g u r e s , t h e i n v e s t i g a t i o n

l - J > t p r/-M = f .?_DATA REDUCTION

Accuracy of DataThe accuracy of th e da ta presented , es timated from pos s ib le e r ro rs i nmeasurements, ins tru me nta tio n, and reco rding , i s as fol lows :

Rolling moment k400 f t - l bi f t f 10 l bDrag 23 l bP i t c h in g moment +300 f t - l b Control sur f ace

Dynamic pressure k O . 5 percentS ide fo rce f 3 l b Angle of a t ta c k +O. 2OYawing moment - + oo t - l b def lec t ion +o 5 O

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Corr ect ions t o th e DataThe da ta were correct ed t o account fo r t he unshielded main s t r u t t i p s andt a i l s t r u t and f o r the f a i r i r i g between the main s t ru t t i p and Lhe body( f i g . 2 ) .The s t r u t t i p and t a i l s t r u t t a r e va lue s u sed we re :

CD = 0.052 - 0.020 s i n aCm = -0.031 + 0.001 s i n aCn = 0.0518 s i n pC1 = 0.0082 - 0.0116 s i n a

The fa ir ing t a r e values used were:CL = 0.111 s i n a , a 5 18O

= 0.034 - 0.093 s i n ( a - 18') , a > 18'CD = 0 .389 - 0.389 COS a - 0. 020 s i n a , a 16OCm = -0.262 + 0.262 cos a + 0.0124 s i n a , a


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more negat ive) upper f l a p defl ect ion s and decreased lower f l a pl i f t c oe f f i c i e n t s l es s than 0 . 5 .

A comparison of fi-gu res 5( a) and ? ( e ) shows th at t ,he drag co ef f i c i en t a tero l i f t fo r t he minimum f la p de f le c t io n t es ted (h 0 and 61 = 10) wasf o r t h e maxim f l a p d e f le c t io n (& = -25O and 62 = 4.0'). This dragi s i nd i c a t i ve o f t he i nc r e as e i n e f f e c t i ve bas e a r e a a s t he f l a p s aref le cte d away from th e body sur fac e. This base a r e a in c re a se r e s u l t s i n aa x i m untrimmed value of Su = 25' and 6 2 = 40 compared t ovalue of L/D = 4.2 when 6,= Oo and 62 = l oo. A change i n m a x i m L/D

f t he same magnitude occurs f o r t he trimmed condi t ions of f i g u r e 6 when thef o r 6 l = l oo and 61 3 p r e compared. The m a x i m u m trimmed L/D f o r2 = 10 w a s 4.0 and t h e a u a r t m was 2.3 f o r

L/D = 2 . 1 when

.,? 61 = 40'.F igure 7 i nd i c a t e s that s i d e s l i p d i d n o t g r e a t l y a f f e c t t he l o n g i t u d i n a l

However, when th e ang le of s i d e s l i p w a sh a r a c t e r i s t i c s a t o r belowincreased from 5 t o l oo, t he re w a s a s izable increase in drag and a smalle duc t i on i n l i f t curve s lope . I n addi t ion, a tl i f t c o e f f i c i e n t w a s reached a t a, = 2 6 O accompanied by an un st ab le brea k i nh e pitching-moment curve. A t P = 0 and 5O, a s t a l l break w a s never reached,

and the l i f t coeff ic ient was a l i n ea r func t ion of t h e ang le o f a t t ac k over t hen t i r e r an ge t e s t e d a -10 to +28O).

P = 5'.j3 = l oo a definite maximum

Late ra l -d i r ec t iona l ae rodynamic charac t e r i s t i c s . - These charac t e r i s t i c sa r e p r e se n t ed i n f i gu r e 8(a) as a f unc t i on of angle of a t ta ck for s e ve r a ls i d e s l i p angles and i n f i gu r e 8 ( b ) a s a f i nc t i on of s i d e s l i p ang le f o r s e v e r a langles of at ta ck . These da ta show th a t the rol l , yaw, and sid e-f orc e co ef f i -c i e n t s are ne a r l y l i ne a r f unc t i ons o f P From t h e yawing-moment r e s u l t s o fi gu r e 8 a) , t he re appears t o be a t r an s i t io n i n the value of the yawingoment due t o s id e s l ip (Cnp) from a low value t h a t e x i s t s a t negat ive anglesof a t t a c k t o a high va lue t ha t ex i s t s f o r ang les o f a t t ac k gre a t e r t han 12'.h i s could be due t o in te ra c t io n of the vortex f low from the leading edge wi tht h e v e r t i c a l s t a b i l i z e r s . It i s a l so apparen t from f ig ure 8 (a ) t h a t t he re i s

sudden change i n t he yawing and r o l l i n g moment a t about 26O angle o f a t t ackf o r 10 s i d e s l i p . This, toge ther wi th th e previous ly ment ioned uns table bre aki n th e pitching-moment curve, suggests that the f low separates on the windwardve r t i c a l s t a b i l i z e r a nd c a us e s a breakdown in the flow over t h e a f t e r p o r t i o nof th e upper s urfa ce and a resulting forward movement of the center ofpressure .The e f f e c t s o f r udder a nd a i l e r on de f l e c t i ons on t he l a t e r a l - d i r e c t i on a laerodynamic ch ar ac t e r i s t i c s a r e p resen ted i n f i g u r e s 9 and 10, r espec t ive ly ,f o r a n upper f l a p s e t t i ng o f - l oo and a lower f l a p s e t t i ng of 20.t i ons i n r udder and a i l e r o n c on t r o l e f f e c t ive ne s s due t o l o ng i t ud i na l c on t r o lse t t i n gs were neg l ig ib l e ; hence , r e s u l t s f o r only one s e t t i n g a re p resented .The l a t e ra l -d i r ec t io na l aerodynamic char ac t e r i s t i c s a re p resen ted bo th asfunc t ion s of angle of a t t a c k f o r d i f f e r e n t c o n t r o l s e t t i n gs and a s f unc ti onsof c on t r o l s e t t i n g f o r d i f f e r e n t a ng le s of a t t ac k . The e f f e c t s of t h e l a t e r a land d i r e c t i on a l c on t r o l s a r e s e en t o be e s s e n t i a l l y l i n e a r f unc t i ons of t he

r e s pe c t i ve c on t r o l de f l e c t i ons w i th on l y s,mll va r ia t io ns due t o angle ofa t t a c k . The l a r g e adv er se yawing moment due t o r o l l c o n t r o l ( C

The varia-

/Cz6, M -1nga5


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evident i n f ig ur e lO(b) should be noted.r eport ed i n r e fe rence 10 f o r th e M2-Fl vehic le , a CnBa/C16a va lu e of abou t-0.2 was obtained during f l i g h t t e s t s . This value w a s considered acceptablef o r t h e l i m i t e d l i f t i n g body m is si on e ve n though t h e r e s u l t i ng r o l l r e spons ew a s s luggish and marginal when compared wi th f ig hte r - t yp e a i r c r a f t re qu i re -ments. Unpubli shed re su l t s of s imula tor s tu di es of th e M2-F2 f l i g h t charac-t e r i s t i c s i n d ic a t e t h a t i t s l e v e l of a dverse yaw could be u naccep table. Ace nt er do rs al fi n , which reduces t h e adverse yawing moment due t o r ol l cont rol ,i s discussed a t t he end of t h e fo llowing sec t i on .

A cco rding t o t he f l i g h t t e s t r e s u l t s

Aerodynamic C ha ra ct er is t i cs of Various Devices Inve st iga tedB o a t t a i l f a i r i n g . - The b o a t t a i l f a i r i n g w a s i ncorpora t ed in to the M2-F2

conf igura t ion.i t was when t he f a i r i n g e f f e c t s were inve s t iga t ed) are shown i n f i g u r e 3 ( b ) .The model was never t e s t e d with t h e a f t f l a p s o f f when t he b o a t t a i l w a s o f f .Because of t h i s , t he comparison of t he r e su l t s wi th and wi thout t he bo a t t a i lf a i r i n g inc ludes t he e f f e c t of moving the a f t f l a p 26 inches f a r t he r back f romth e moment ref ere nc e. However, t h i s e f f e c t i s probably a s m a l l percentage ofthe e f f ec t o f add ing the b o a t t a i l f a i r i ng . The ba s i c l ong i tud ina l aerodynamicch ar ac t e r i s t i c s a re shown in, f i gu re 11. The re su l t s ar e shown f o r th e e levonon and off and fo r th e a f t f l ap s a t -10 inc idence .f i g u r e i n d i c a t e s t h a t t he b o a t t a i l f a i r i n g re duce d t he d r ag and i ncr e as e d t h el i f t- c u r v e slo pe , and hence inc rea sed t h e untrimmed maximumIt i s a l so ev iden t from th e pitching-moment r e su l t s o f t h i s f i g ur e tha t t hel o n g i t u d i n a l s t a b i l i t y of t h e M2-F2 w a s improved by the ad di t ion of th e boa t -t a i l f a i r in g . The presence of t h e el evon a f fec t ed the con t r ib u t io n of t heb o a t t a i l f a i ri n g , e s p e ci a l l y a t low angles of a t ta ck .

(des ignated M2-Fl) bu t n ot on th e M2-F2 c onf igur at io n.and the model co nfi gu rat ion ( a s i t w a s when the e levon ef fe c ts were in ve s t i -gated) are shown in f ig ure 3( b) .t e s t e d was di f f er en t f rom th a t of t he M2-Fl.)ch ar ac t e r i s t i c s fo r symmet ri ca l de f l e c t ion s a re shown in f ig ure 12(a ) and thel a t e r a l - d i r e c t i o n a l e f f e c t s f o r d i f f e r e n t i a l d e f le c t io n s a r e shown i n f i g -u r e 1 2 ( b ) .i s t i c s were ge ne ra l ly improved by the presence of t he elevons. The d at a showni n f ig u r e 1 2 (a ) i n d ic a t e t h a t a 10 change i n angle of a t t a c k had a g r e a t e re f f e c t t han an equa l de f l ec t io n of t h e e levon . This sugges t s t h a t t he body-induced upwash, which in cr ea se s wi th ang le of a t t a c k , i n t e r a c t s w i t h t heelevons.

The dimensions of th e f a i r i n g and th e model Config uration ( a s

An exam ina tion of t h i sL/D by over 0 . 5 .

Elevons. - The elevons were used on the original M2 conf igura t ionThe elevon dimensions( I t should be no ted th a t t he e levon po s i t i on

The lo ng it ud in al aerodynamic

These da t a i n d ic a t e t h a t t h e long i tud i na l aerodynamic ch arac t e r -

The l a t e r a l - d i r e c t i o na l r e s u l t s shown i n f i gu r e 12 (b ) i nd i c a t e t h a t veryl i t t l e yawing moment i s produced when the elevons are d i f f e r e n t i a l l y d e f l ec t e df o r rol l c o n t r o l , t h a t i s , Cnga/CIBa 0. Hence, one method of e li m in a ti n g-h e large a d ~ e ~ s - e ~ ~ ~ - o f _ t ~ ~ . - M 2 - F 22n f i gu ra t on prev ious ly d i scussed i s t oincorporate outboard mounted elevons.___ __ ~ ..-- ---*

_1_1--- ___llI_

The dimensions and arrangement of the se f l a p s ar e shown i nc o n t r o l e f f e c t i v e n e s s of t h e s e f l a p s i s compared t o t h a t of

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t h e M2-F2 u pp er f l a p s i n f i g u r e 13. I t i s e vi de nt f rom t h i s f i g u r e t h a tchanges i n l i f t , drag, and pi tc hi ng moment are l e s s per degree of f l a p de fle c-t i o n t h an a r e r e a l i z e d w i th t h e u pp er f l a p s o f t h e M2-F2 configurat ion eventhough the t a i l volumes ( t a i l 1engt.h times su r face a rea ) a r e almost i de n t i c a l .This i s probably due to a g r e a t e r inf luence o f t h e M2-F2 f l a p on t he body f lowpatterns. However, if trimmed re s u l t s a re obtained from th es e data , drag f ora given l i f t i s s l ig h t ly h ighe r f o r t he upper f l a ps . Hence, t he t r i m drag i ss l i g h t l y lower f o r t h e a f t f l a p s .

Quasi-wings.- The dimensions of t he con figur atio n wit h th e wing ro otf a i r e d a r e g iv en i n f i g u r e 3 ( c ); he photograph shows the arrangement withth e ro ot un fa ir ed and unsealed. The shape of th es e wings w a s i n t ended to s i m -ula te landing gear doors tha t could a l so serve as sim ple l i f t i n g s u r f a c e s .The lo ng i tu di na l aerodynamic ch ar ac te r i s t ic s wi th and without t he wings arep r e se n t ed i n f i g u r e 14 Results are shown for t w o incidences and with andwi thout t he wing roo t f a i re d and sea led .improved th e performance, es pe ci al ly with the roo t se aled and fa ir ed .maxim L/D w a s increased by about 1. These l i f t i n g su r fa ces would not onlyimprove th e performance b u t would al so reduce t h e landin g a t t i t u d e substan-t i a l l y . For a 5.2O wing incidence a t CL = 0.5, t h e wings would reduce a byabout 7.5'. The maximum in cr em en ta l inc rea se i n CL achieved f o r the rangeof v a r i a b l e s i n v e s t i g a t e d w a s 0.22 a t This i s e q u i v a l e n t t o a m a x -imum l i f t . c o e f f i c i e n t o f 1.1based on th e pro jec ted a re a of the wing and i s anu n us u al ly h i g h v al ue f o r t h i s type of l i f t i n g s u r f a c e .t h a t t h i s t y pe o f l i f t i n g d e v i c e i s a promising method of improving theper formance of l i f t i n g body veh ic l es .

It i s apparent that the quasi-wingsThe

CL = 9'.These resul t s sugges t

A s imple computa t ion us ing the resul t s o f f i g u r e 1 4 shows tha t t he cen te rof press ure of th e re su l t an t fo rc e increment moves forward of th e wing pane lsaf te r wing s t a l l occur s . Th is i nd ic a t e s s ign i f i can t i n t e rac t io ns between theflow about t he b as ic body and the quasi-wing pa nels .

Outboard ve n t r a l f i n s . - The outboa rd ven t r a l f i n s a r e descr ibed i nf i g u r e 3 ( d ) .occu rred on th e lower surfa ce of t he body.g a te d , t h e t h i n o ut bo ar d v e n t r a l f i n s and the t h i c k o u tb oa rd v e n t r a l f i n s .The t h i c k f i n s w e r e designed t o withstan d high-speed aerodynamic hea tin g.

These f i n s were in tended to s t ra igh ten the outboard f low th a tTwo conf igu ra t ions were inves t i -

The aerodynamic ch ar ac te r i s t ic s a re shown i n f i g u r e 15 f o r t h e t h i n f i n sand i n f i g u r e 16 f o r t h e t h i c k f i n s .b o t h t h e l o n g i t u d i n a l and d i r e c t i o n a l s t a b i l i t y and s l i g h t l y d ec re as e t h ero l l in g moment due t o s id es l i p .s imi la r b u t smaller t h a n t ho s e of t h e t h i n f i n s .

I t i s s een t h a t t h e t h i n f i n s i nc re as eThe aerodynamic e f f e c ts of t he t h i ck f i n s are

C en te r d o r s a l f i n . - The c e n t e r d o r s a l f i n d e s cr ib e d i n f i g u r e 3 ( d ) wasin tended as a f lo w s t r a i g h t e n i n g d ev ic e d ur in g a i l e r o n c o n t r o l s e t t i n g s .l a t e r a l - d i r e c t io na l aerodynamic cha rac t e r i s t i c s a r e shown i n f ig u re 17 as afunc t ion o f r ol l c o n t r o l s e t t i n g s . The b a si c l o n g i t u d i n a l and l a t e r a l -d i r e c t i o n a l a erody nam ic c h a r a c t e r i s t i c s are no t p re sen ted s ince the e f f e c t o fLThe s c a t t e r i n t h e moment coe f f i c i en t ev iden t i n f i g u r e 14 and inf igures 11 and 12 i s a re s u l t of the reduced accuracy due t o the low t e s t

The

dynamic pressure (17 l b / f t 2 ) .7


10/45

t h e d or sa l f i n on t h e s e c h a r a c t e r i s t i c s w a s negl ig ib le . The r e s u l t s off i g u r e 17 i n d i ca t e t h a t Cn8,/C18, would be reduced from about -1 t o -0.2 i fth e dorsa l f i n were used on th e M2-F2. The e f f e c t on th e r o l l c o n t r o l wasvery small. Hence, i f th e l ar ge adverse yaw due t o r o l l con t r o l p r e sen t ont h e M2-F2 conf igura t ion i s unacceptable, one s uc ce ss fu l method1 1 afmarked3_ydecreasing i t i s by a dor sa l f i n suc --asLhat.~Lg2______- -

CONCLUDING FEMARKS

The maximum untrimmed L/D of t h e M2-F2 co nf ig ur at io n w a s 4.2; them a x i m trimmed L/D was 4.0. The model had po si t i ve s t a t i c lo ng itu di na ls t a b i l i t y over t h e e n t i r e t r i m range inves t iga ted .The adv er se yaw due t o r o l l c o n t r o l w a s la rg e bu t can be reduced by th eaddi t ion of a small dor s a l f i n between t he uppe r f l ap s .Wind-tunnel t e s t s of th e M2-F2 l i f t i n g body have shown t h a t t he re ar es i gn if ic an t in te ra ct io ns between t he components and t h e body. Thus, th e

aerodynamic ch ar ac te r i s t ic s determined f rom t e s t s of is ol a t ed componentscould n o t be superimposed t o pred ic t th e ov er a l l aerodynamic c ha ra c t e r is t i csaccura te ly .

Ames Research CenterNational Aeronautics and Space AdministrationMoffe t t F ie ld , C a l i f . , Nov. 3, 1966124-07 -02-10-21


11/45

REFERENCES

1. Kenyon, George C . ; and Edwards, George G . : A Pre l iminary Inves t iga t iono f Modified Blunt 1.3' Half -Cone Re -ent ry C on fi gu ra ti on s a t SubsonicSpeeds. NASA TM X-501, 1961.

2. Rakich, J ohn V. : Supersonic Aerodynamic Performance and St a ti c - S t a b il i t yC h a r a c t e r i s t i c s o f Two Bl un t -Nosed Modified 13' Half -Cone Conf igu ra -t i o n s . NASA TM X-375, 1960.3. Dennis, David H.; and Edwards, George G . : The Aerodynamic Character-i s t i c s of Some Li f t in g Bodies. NASA TM X-376, 1960.4. Kenyon, George C . ; and Sutton, Fred B.: The Longitudinal AerodynamicC h a r a c t e r i s t i c s o f a Re-entry Con figu ratio n Based on a Blunt 1.3' H a l f -Cone a t Mach Numbers t o 0. 92. NASA TMX-571, 1961.5. Rakich, J ohn V. : Aerodynamic Performance and Static-Stabili ty Character-i s t i c s of a Blunt-Nosed Boat ta i led 130 Half-Cone a t Mach Nunibers From

0 . 6 t o 5 .0 . NASA TM X-5'70, 1961.6. Kenyon, George C. : The Lateral and Directional Aerodynamic Character-i s t i c s of a Re-entry Configuration Based on a Blunt l 3 O Half-Cone a tMach Nmibers t o 0.9 0. NASA TM X - 5 8 3 , 1961.7 . Axelson, John A.: Pressure Dis t r ibu t ions f o r the M-2 Li f t i ng Ent ry

Vehicle a t Mach Numbers of 0.23 , 5.2, 7 . 4 , and 10.4 . NASA TM X-997,1964.8 . Horton, Victor W.; Eldredge, Richard C. ; and Klei n, Richard E . : F l i g h t -Determined Low-Speed L i f t and Drag Character is t ics of the LightweightM2-Fl L i f t i n g Body. NASA TN D-3021, 1965.9. Mort, Kenneth W. ; and Gamse, B e r l : Ful l-s cal e Wind-Tunnel Inv est iga t io n

NASA TN D-3330, 1966.of th e Longitu dina l Aerodynamic Ch ar ac te ris ti cs of t he M2-Fl Li ft in gBody Flight Vehicle.10. Smith, Harr iet J . : Eva lua t ion of t he La te ra l -Di rect iona l S t ab i l i t y and

Control Cha ra ct er is t ic s of th e Lightweight M2-Fl L if t i ng Body a t LowSpeeds. NASA TN D-3022, 1965.

9


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10


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8>

NI

>

I

' d11


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(a ) Three - q u a r t e r f r o n t v i e w . A-32524Figure 2.- The model mounted i n t h e 40- by 80-foot wind tunnel.

12


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(b) Three-quarter rear v i e w .Figure 2. - Concluded.

A-33440


16/45

rr)Xlom

+X(ur-pIXII

I1> hKJIm

14


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ua-ILLa

ta

vz- N >

WE0InhU

.-+m


18/45

Pro jec t ed a reah ide : 12-112 f t

A l l dimensionsin inches

15 -- A l l edges have IrI-_

156 177Body stat ions Lkzj-A

A-31466c ) D e t a i l s of quas i -wings.

Figure 3 . - Continued.16


19/45

E.-

Umrl

JIzaa

8I-0

tz


20/45

18


21/45


22/45

20


23/45

21


24/45

22

0m8


25/45

nN \J

EL)

dI

oI

23


26/45


27/45

25


28/45

I

26


29/45

.I

0CY -.

-.20 0

c2

.04

0

-.04

-.O 8-. 2-

(a) Resul t s pr esent ed as a f unct i on of CL.Fi gur e 8. - Ef f ects of s i desl i p on t he l at er al - di r ect i onal aer odynam cchar acteri st i cs of t he basi c W-F2 conf i gur at i on; S, = - l oo,

6 L = 20.


30/45

.I

0CY

-.I

-.2

.O

.04Cn0

-.04816

- 0 -.04

C l 0

-.04

.08

-.I2-5 0 5 IOP d e g(b ) Resul ts p resen ted as a func t ion of P

Fi gur e 8. - Concluded.


31/45

CY

.

0

-

0-5

.04

0I I I I I

- 12 - 8 - 4 0 4 8 12 16 20 24 28-.04a deg

( a) Resul t s pr esent ed as a f unct i on of a .Fi gur e 9 . - Ef fec ts of r udder def l ect i on on t he l at er al - di r ect i onal aer odynam cchar acter i s t i cs of t he bas i c W- F 2 conf i gur at i on; S, = - l oo, 62= 20 .

29


32/45

C Y

. 04

0

-.04

.04

0 0 2

Cn 0

-002

-.O 4

0 0 2

C2 0

-00 -Br

( b ) Resul t s presented as a f unct i on of 6,.Figure 9. - Concluded.

30


33/45

C

.04

0

-.04

.O 4

Cl O

-.04

-.O 8-

00 IO

I I

-4 0 4 8 12 16 20 24 282 -8a deg

( a) Resul t s pr esent ed as a f unct i on of CL.Fi gur e 10. - Ef f ects of ai l er on def l ect i on on t he l at er al - di r ect i onalaer odynam c char act er i st i cs of the basi c W- F2 conf i gur at i on;s, = - 100, 62 = 200.


34/45

.04

0

-.04

.04

0

-.02

.02

0l-.02

8

-.04

( b ) Resul t s presented as a func t ion of 6.Figure 10. - Concluded.

32


35/45

33


36/45

34


37/45

.I

C Y O

-.I

.04

- 04 0 4 8 12 16 20a9 deg

(b L a t e r a l d i r e ct i o n a l a e r odynamic character1 c f o r t h r e e l a te r a l cont o1s e t t i n g s o f el evons.Figure 12. - Concluded.

3.5


38/45

.77

.5

.4C L

.3

.2

.I

0

.3

.2CD

. I

0

-04

.02

-.02

-16 -12 -8 -4 0

Figure 13. - Compar i son of af t f l ap cont r ol ef f ect i venescont r ol ef f ect i veness; z l = 10'.36

~~

.5

48121618

.4C L

.3

.2

. I

0

.3

.2CD

. I

0

-04

.02

-.02

0Ahn

0nV

Figure 13. - Compar i son of af t f l ap cont r ol ef f ect i venescont r ol ef f ect i veness; z l = 10'.

36 L_r

s wi t h upper f l ap

~~


39/45

37


40/45


41/45

CY

Cn

ventral f ins deg

I I I I I I I 10 de9

0 4 8 12 16 20 24 28 32-.I6 I-12 8 -4(b) Lat er al - di r ect i onal aer odynam c char acteri st i cs.

Fi gur e 1.5. - Concluded.39


42/45

f

- I

O o o a I I I

Ju

40


43/45

.I

0C Y -.-.I2

.08

.04C

C

.04

-.OE

.I 2

.O E

.04

-.OE

- 8 - 4 0 4 8 12 16 20 24 28 32a deq

(b) Lat er al - di r ect i onal aer odynam c char acter i s t i cs; S, = -150, 6 = 30.Fi gur e 16. - Concl uded.- 41


44/45

.I

0

CY -.I

-0 2

.08

-04

Cn 0

-a04

-O 8

-04

CL 0

-004-16 8 0 8 16 24 32s o , deg

Figure 17. - The effects of t he d o r s al f i n on t h e l a t e r a l c o n t r o l e f f e c t i v e n e s sof t h e b a s i c M2-F2 conf igu ra t ion ; S = - l oo, 6 2 = 20.

42 NASA-Langley 1967 A-2253


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Th e aeronautical and space activities of the Un ited States shall beconducted so r l ~o confribuie . . . to the expansion of durrian knowl-edge of phenomena in the atmosphere and Jpace. Th e AdministrationshaIl provide f o r the wides t practicable and appropriate disseminationof information concerning its acticities and the results thereof .

-NATIONAL ERONAUTICSND SPACE AC T OF 1958

NASA SCIENTIFIC A N D TECHNICAL PUBLICATIONSTECHNICAL REPORTS:important, complete, and a lasting contribution to existing knowledge.TECHNICAL NOTES:of mportance as a contribiition to exisiiiig knawledge.TECHNICAL MEMORANDUMS: Information receiving limited distri-bution because of preliminary data, security classification,or other reasons.CONTRACTOR REPORTS Technical information generated in con-nection with a NASA contract or grant and released under NASA auspices.TECHNICAL TRANSLATIONS: Information published in a foreignlanguage considered to merit NASA distribution in English.TECHNICAL REPRINTS: Information derived from NASA activitiesand initially published in the form of journal articles.

oi of ..1.... --PECIAL PUBLICATIONS I=fcrmatien derived fmm V L L I U C L"NASA activities but not necessarily report ing the results of individualNASA-programmed scientific efforts. Publications include conferenceproceedings, monographs, data compilations, handbooks, sourcebooks,and special bibliographies.

Scientific and technical information considered

Information less broad in scope but nevertheless

D e t ai l s o n t h e a v a i l a b i l i t y o f these publ icat ions m a y b e o b t a i n e d from:

low-speed wind-tunnel tests of a full-scale m2-f2 lifting body model

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