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NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

TECHNICAL MEMORANDUM

NO. 1104

THE INFLUENCE OF THE JET OF A PROPULSION UNIT

ON NEARBY WINGS

By H. Falk

Reprint

Der Einfluss eines Triebwerkstrahles auf elnen in Nahe befindlichen Flugel

untersuchungen und Mitteilungen Nr. 3200

washington September 1946

LIBRARY Cnpy JAN 14: 1962

MAunED SPP. ~rra~ f~ (~E~f EI HCdS ; rt, u;: \~

https://ntrs.nasa.gov/search.jsp?R=20050009881 2020-05-19T17:21:07+00:00Z

By H. F 8 1k

ADSrl'R.i\C'I' ~ The pl'8sellt h:ves ti ,::.:atl.on Wi..tS intended to usce:ctR:in how fa:;: a L 8.~J u .,.llt is subj o c t to c1:'L st~lrban ('.e s b y t he J e t of a p:rop;)_lsion unit. Tl'1e .p8.rjpmetE; ~l·' S -:If)c·rJ. -;;fl-.Lj C.h :~l} is d~ .. s t lJ3"l binE; influence d epends , anJ the V& b16S it re&ohes , h ad to te deter~;.ned.

I. Stat e n~ nt of the pr ob1e~

II. Test pr ocedure

III. Results of mea~ur er~ct

\7 .. Su~nm8ry VI.

P,dclltlon a l forces Gre l!rob ab 1~l e :;;:e rted upon a supportinc wing , for instan~e a tai l unit, if it is loc a ted b eJll.nd a propu18 iO :1 unit l:'.':Lth an e1111 tted jet. rI'1J.ese fOY'Gas nJ.ust be tl'8.ced bac}{ to t}lE-'; l)reSerl'28 of -c)-le j et. 1" 1g1).1'(; 1 1' G[J~ e.scnts sche llia t=_c DlJ.y s,lch an 111'1'an,.;8 -ment . Forc e s of th i s L i rld ;-"lHy ,-lib tUl"!') the ~'; tab :L l:'Lty of fl ie;h. t . A j)asic ~: 6st vli11 J."lelt) u s to dEcer-tain the inf lue nt :i.a1 pnr anlete :e s and .~\') de termine t113 [n8g.nt tude of the fOJ:"ces 0

- - - - ... _-. ----. ----.------------.~.--------- ---- -.----•... --.•. ---.----- .. --.------.~----.--.-.-. ~

·;~ I De l'> l'J' -'Lnf l ' l Qs ""lll~ ~ 'l' -(' l· e, b, ,· , (:, -I · ,' ~ q ·r-l'a· l__, J·,e.' l 8 1-,.f 1"' ~rle·.V) ·ir] • . -. "- - . • L_. I...J V .... ......... \ .... '-J. _ ,\ __ . .t .... ~ ..... • .1 _ .... ..... _ ~....... .....'" _ '-' ..L ... .L ...... •

Nahe befll1d l::'ch'3n F:h:ige1, 11 Dl~1)_ t 2ct1.e Luftfal;rtforschung , ·U:ht c: r ,s~:..chung::inund P ittE:.llunge n lTr . 32000

2 lL4C A TM No .. 110L!.

EssentIally , there are two effectR of decisive i Flportnnc.e . '1'he first e ffect is bctssd on pot;c:nti8.1 thf;ory and VI as a l :r t' sr.'l.y- t.I' Gatod by' P . RU.dE; n (1 ) for tlw e ase oJ:' a plane WiLl£:; :in the pro:xlmi ty of a plEine jet ( or of c-' region w~th slo,N fJ.OVT)" '1'he pressure (1i~~tr i­lmtlon on the: wj,ng is dL~ tu:d)(.;d iY;',r tho UDE:~v,:nl d:LstI':1.but10n of the total pressll.re; adc1it~.()),"!iJ.l iorce~) result . Thero--1'0],,(:; , the t}:1:l.c1nl'JsE' of tbe viJ :',nt: w:L ll 'o,=~ cf ForGmost I mpcr t3.nee in this effect . (Other qu a:lt ltL;s of influenc.e will be discDsseJ later .) An infinitaly thin wine a t zero an:le of attock wilJ. not exp0rience any forces .

The second u:CfE')c t :',8 [(.111nded on the int e r mixIng of the j et Vi i th tll.e SU'I' ound i ~~g i 10"" nc t ''JEi.2e d on potent ia J. tl1e OI)',Y- 0 'I1hd t 11r1Jl11en-c :3pl.' ·2ur;.tng c.a"L'.st"=; C~ the c'"1)1)(; D.).'" c:llce of a v elocity com"onent d irected Low&rd the jet in certain re cions . 'I'h ~'se condiLi,onn iVer~) d:l.E'C"t.l.S :.l(' d 1n nu;ue:cous ~ eDorts siace W. Tollmlen ( 2 )' r~centlv the',' ~e~e also

l - ~J l.

tJ"'es+or1 1111'(n " l ,]' ,'a 'l] v ·t::·Ol.V ' +1-, ,::. Al'lT'e oF" [- ", ,::, ru·'d'.a} ' ioJ·'1 8J.." 'l v J . uv.J. _..-I. . J . 1...1 _ ...... , J . . l~ .... _ ~ v . .L J.L..J. ..J ...... ..... . - r-' """Pt r.·jA i-I'-'i (,pl "1 (·t' 1-",,- ('\ pn ·hs·J- ( :'::' ) 'In'~ 7.:) (~ 2&'l-' 1 c> \ 'r o k " ( II ) v d U L' .....; l.J . • L ' ...... • J ........ ~ / ... L. '"-' IJ \ •• / ... _ ..• ~)_ .. ..I.. . u:...J . v. ~_)_ ..... ___ ~. _ •

rr ~'l8 followinp: pfJ.:,~·D".1E'. tel';::: :0.r:') ~)ro 'bnhly the "il08t

i nfluential. (m.E,3 ~ the j.l].'Op"l.u::L on :et , ';.;hi(;h fer th is invest.t:.:;8tlon is aES1)m\~)0, to bUlLlhcBt.3d, ';,111 be eh2Y'9.c.-t Arizecl by Lts vc:;loclt;:c vi\. ).1.'1. th,;:; exit or the .~)ro -

pul"':i.on nn:l.t • vA dJ.fn"r's f rom t: i.e l..Ulcl:i'.sttl.T1J(·d oncor.::~ng

flow vO . velocities

r a t:Lo

the d:l.ffsI'(;'."lCO

(Comp 8 re ( 5) .)

v/v of the t vvo h 0

Vo will a l so play an

The po.:.ll.tion of t 1'lfJ '.:1Jing 1n relation to the jG t 'Nil l be mo::;t lr!l i.",oI'tant :fOj~ the Int c rf ~;rE;n c 3 cffsc: t u~on the wing; there .:Core , in OLD.' c 8S() of the r Dtd.t iOD!':J.1y sYlii.m8tr :Lc~n j et the eoordi:nate3 .x. and z of foJ:" inst21:ce th,; 1e 8c11ng edge in the t~ oordinate 3-YS h'3m c11&r 8.ctc;r ized i n i'iClJr c 1 vv1 11 be of '11~l.ln jL()~Jorta~:1c. 8 . ~L'hc wlnt: span and t h s coordinate of the ~lng in the direction of the span rlr<'1 not con.sid.e2ed in our LlVC .. 'lt iz.EJ.t:Lo.n r1incc v.:e CSSLll1le

thE'; S :)Hn in both d'il'ect~.ons t.o '0,:.1 lar [';e cCMt:9b.rcd Ai tIl the i st di8.11'ete·Y' O~l tll~> w~np' it"l s lf :\ t<) Ull c hw"'s d a'ld i ts C.~~o~'d i · will b~ of "inf·1;J.Gn;~'3 ~'thu · .~ra::t;i·o"" d/L ' no l e3~3 than thG pat:io d / OA (thic lrnc8:J of _the wine-j et diameter) . tIlhe pr ofi l e forw, v.hic;h will also 1)'3 oj;

i nf h H'm.ce, was ch8.nge d but s11[:lltly in (rur 8~:pe:rtments since exlst:Lllt:; vv'in[s &1'8 t o be used {Dr th8 lilcas·:.u'ements; we J.im:i.te (..1, ourseJ.ves to SY"1nm<:; trJ.(; c:.l p1'o.fJ 183 . Bo th the

propu l sion un::.t ar'.cL tbe wing Gb.y be incl:Lned t oward. tIle dIrE c tiol) of the ollcomiuf; flov! 8. i 1cl so l'nrm an angl e wi tll. r e s ps ct to each 0~h8r ale o. Inv8Btig3t~ons wure 2ade on l,\T fc~:" condjtious of syrr:m-3 t:cy so a s to hold c~ovl[n the extent of trlb rJleas~ule~ne;lts; nl0reo·~.r0 r, tIle '"v lllr V\fE.iS G. l vJa·~.1 · s

adjl..lSL,d J..nct.e dir e ction of the unc3 istuTbed oncoming floVi s o tlH~·::; ;;.']. tll.oU t in Jcf:. r fe::'"8Lce eff ec t tlv3 1. ift was Z8~~O o II1 2!10 St of) tn.s P.);:'11eri,, '1'c.;J:1ts t l18 Je:t l .::f t t11G pl~O-

puls:ion unit 1Tl t' ~le di:.:'ecti'.)L\ of t.hu oDccr,ii '1,~; f low . Onl·y Ll a few cas es th,.~ &Xi3 o f the pr'cpr ls:l on unit wa :J .i..ncIiIled nt an &-':"r:1e a to\vClrd tJL onconin; .flo':l .

Pi[::llre 2' [ .i'.It.S E SC'.11E:'::lfltic l' (· ·'l)J'sse.nt&t.ioYl o.f tIle e:·~pt;r:1.:a(mtB.J.. arro.n2~el):ent . 1~ mc-d l,d pY'o)~)1::31 ()n tm:l.t \l'iith 8. bv.ilt-in blerer \:h:1.ch hE,d ;)esrlx~(:., (l :JEifo::::'G Lv 11.. I:~ a (.311er)le ((; ) 1;VfJS Sl~SJ!clJ.dGll if} tl16 open jet ~f -Nlnd tUDll.61 I:n ( 100 x 1.51] ). A ';::1.n3 i." .i bS supporte d in t h e cus:::0nlaL'·~· [(!8nner bJ tbs +-Lr6<3 ·-co:,:i.)cnent oH18.1,-ce beh:lnd t he propl: lsio:n U:lit in tlK> C:3:nter of the jet; hmV\jV,3r, o nly the lift wa s r~asu~ed . Tha r e lativG position of PI" or~uls lOD uni t 8.:-1d -;IVins Vi as C',i:::'8.1-1 ; ~:ed bj f:Lxing t~:l (': wing and s1:11ft:1.ng th3 propulsion u.liit ul"w8::,d ""-Ld :Ln t ):l (: direct:Lon of the opening of the TIozzle . All di stunces were rnBasur~d in units of db (d ~ di~net8r of the exi t oupnln~ of the propul sion u nit = 1"-701'1111) 0 In tiLe Y:.-dtJ' (: . cti~n thb d:LstanGes x/dA = 1 , 2, 4, 6, 8 D.r' d L1 z - d.Lrcction the re g l on 0 ~ z/dA ::" J..~ vle r e r;;8G.sUI'CQ. Seven different r lltios v / _t1 r' ~ lc·· lv ,- In - 0, '7 r i' ..l -, c"\e:: ') o·r::: ') 5 :z 0 - A V 0 ' .- alL, . - u ,; .(, v 0 - • I ! , • -) , <- 0 ) , L . ' j ' ,

and 4,0 aru ap]ortion~d to e2 ch p oint behind the pro ­pulsion unit . T~G first v a lue co?rCSpOl~S to the nodel pTopu13:Lcn uni t at r8at . Ad.Ji .. tlo:laJ. 'J10aSUl~ 0n8nts were t &ken for stAt ic co~ditlons. 8xcc t l: conform to the VE lu3

Tl'JJ3 ::1(;;: s tt~: 6111E: 1.'1 t CLOG.cj D.ot~

v /\ Iv ::; co s i.neE: the 'f:hole _.... 0

wInd- tunnel 5et hud baen pu t i~to a sliCht ~ot l on. Generally , the j et velocity VA W~ S kent cons t snt a t

I ~

90 ill 3; Vo was ch2nged ac~or~inzly.

'T1.1r oo d.i.J~f· E;r' t;r1.t vlir.:.gs \'/:1. tl~ s~)rJ~.-:1:~;tj~lGE:l 1)1")01-:11e8 8rld the; folJowLlC churG.ct ;:;ris ti C:3 v.' (: :r 8 L t 0111" dispo s a l for ElO IlSUrel;lcnt :

NACA 'rM No . 110L1.

VHnc~ I h o.d a rilodifj.o d Joul~ ow31d "PI'o.f'ile vi lth incre o. sed angle or ' thc tra i ling e d ge a nd. s t ra i gh t s ide s; wi ngs II and III h a d the cust mi'l a r y NACJI drop sha~pe .

TIl e E:.n o; l e s of 0.tt a d ;: of t h e ·~) 1 ' opuI8ion unit CL = 3° and a = 60 · 0 11 wi ng II we r .;:; 11lG8.surc d in t b e S8.mo arr [l nE:~Gi1w nt e S inc e a t a = 0 t h 0 f lo\;;l t s n o l onge r 8 ~nnmo tr 1c8.1 t o t ho ;:txis of t he l-'I'o Cu l s:Lon l h ll t, n egGti va z-vEtluos a l s o rH.:l.d to b e m (": f':ifl"l).l' c d. s:i.!:nu ltLlYloo iJ.sly . In orde r t o kee}) cu t of t hC'; d is ·l;I..~rb n ,)c e r dn se of the s 1..1s.ponsion of the propulsion un it t ho latte r wa s t~lt o d in opp osite dir e ction a t th0 Sc~r~le £:lllc l e o J:' att ac l~ ; thc r o fo:'ee, the vling alw8ys r Ema i ns i n t he r e s ion un d orne &th the propuJ.slon unit.

'rhe r e sults are l' uprcs e nt e d gr 8.ph lcally In tho form

of a lift coe ffici ont c a * various x/dJi and VA/V 0

In d o::mcnde ncy on z IdA for ." , I' H

in fi gure s 3, 4, and 5. Tho

lift is r e f err e d to the sta[j~1[-l.tion pr e ssure of the fr ee

stY' (: am pV0

2 /2 and to the ar o a d l".. x 1. 'rIle j e t

dia~e t er d A ~at her tha n the span w&s i ns 8rte d as the

l e n g th :t n order to k e e p the I' O sul t il, d 0pe nd6 nt of t h e s p an. FiGure 3 include s al l the v a l ues for the win3 I with 8n ang l E:: of a tt a ck a = 0°, The cour se of the curve sh ows a distinct max :Lm.um und c Ol'we qu.e u t l y 8n D. s -ympt o tic f a llin g off t owar d z ero with increa s ing z-vBlue s. The ris e f~om z ero tovli Elrd the max i mnm val1l0S 1s s teep c ornpo.rE:d vlith the decline. The curve s f or l1eSB.t ~L ve "il "-'. 1ue s Dr e to be invertt)d vli.th r e s p e ct to the 2uro point; this process also inverts the Si gn.

The extr8me valve of ca"~ lies f or [1.J.l x-valn.€s n car the je t boundar~ ; ~lth increasing x it mo ve s

5

sL ~;b. tly outwbrds . Vii t ll Vi'/Vo d:1..ci i nishJ 112: tl!.e 'cnax:l.mu.r,l v:i.lu.e c ',- also dec.reases . S:he l atera l force wh1.r;h is 0.

dJ.rE~c~ecl tOij'JaT'd t ~J.G jet for VA/v o > 1 should have the

opposite (:i.lrection for vi~/Vo < 1. '1'h18 Cir CUlJ1s tan cO is not cd.·Na·y .3 t'rougbt out clC:8.rly b y the meclsurefllcnt, cl'ue probsb l y to i nacc'J]'G.cl88 in m 0 LLSUe"L1 J.C .

Generally sDe ak ing , the s&r~ condItions pre v aI l for wln~s II and III"as fo~ wjng I as shovn jn fi~ures 4 ELnd 5 . '1')"}.6 COUl'<,'e of t;w Cu_,"ve r' e t 1:d.ns tb.o S;3.me fOJ.om ; nor dOes tbe lc'ccil ")(1~<ltion of th:, I.V.:J.x l.r"f!.Ulll C1Jcll1c;e . 'The ma.:;cima for the three \f:ii.n.:.:: s diffe r ~1.11 8i2'.8 only .

Fi gllre 6 ~3lJ(:W3 the }'esulc.s of r:lE:<=tsLll'ol.lE:nts for statlc c :mG.l t:l.ons. [ere tL.e 1 J. ft (~ r)e.f'ficients c~-::- ·;:-

0.

are referred to PVfJ,,2/2 o 'l'l.e ::;Y' 8l)n.S SLO'N t.Le: course £'01"

v arIous x-values .

~'he me G.surr';ments fo:.:' the vor l. Dg w:i.th t,lle iJropu ls loll. uni t &t iln in8linat';'nn &:1."e co:rrpi.led in fil..;nr6s 7, 8 , End 9 . Tt.l8 c'J.rves 8.},'8 not SYlnlCl8tI'ic a l wltb re gnl'd to the !7,t"ro :"oil~t . j, rL".nc'~ oi' dL.1Gct inf luence mU3t be c1ist ingulslle d from a T'G?;ion of lnter.r'E-renee . If the j0t is pc-d.nted at; the w ~1. nz; t:1Gre :':' i'j~!UJ.ts in our 8.rri..ln ~·fj!nurt a ne f; fi.tiv fJ lift of tl!.c wIne . In til.e lllaL1 , the same ccurse appears for' tho positive ca-;c vi"lues Q;; :tnd:l.Ga~:ed for

a = 0°. '1'h8 negati'J8 c a'::' va lue.s att[·in Ll8.xJ.:-:1Um values which diffe r c cmsi.dersb l y from the '.'os:tsive ones . '('ho slo~e t owar d zero i s nmch greater for tlJ c negative value s than it wns in the Dositive section . With incr8~sinG x t hd point of t :::' HnsitJon throug)]. the ::'c;)Y' O 11.110 a pproache s }lien or z ·-va lues.

A m .. ll~;l)eI' of correcticGs had to be i ntroduco d in 8 v a l u 3.t ill. ,2; the r esu l ts of 1'10aSul' l::ment; the.so cOT'l'ections shall be trcat8d subsequolltly . :Lacl1 wing showod a s~;Hi l.l lift even witb~ut propuls ion j et; this l ift 1s caused by t he on8 - sidecl susv;n.slon of tbe propulsion "Wlit. Anotll.Gr c:ffc ct of di.'.n:;urb a~-lc e L::l to 08 tlo dce d bac1\: to the position o.f tho propuls ion unit with re3)8(:t to the o:penLtC of tho nozz 18 . A ncrma l fo::. r,l::d~i on of the open~ j o t is incre as L~1 ,r:.:ly l mp0diYl the lrlOI'8 the propulsion uni t

6 NACA Ti\1 No . 1 10L~,

1 8 shifted from tb,E; c ent e r of th~) je t towC',rd t he bO"L~:'ld8.'~y . 'JlJ:1t":: grc.8 t es t C-;.:LSt"11TDH;1CU is to bc expecte d fer t l'lD \falue: S X,/d'i = 8 and r 8 I H ti ve IS hi gh value s

h-

of Z/ d,\ bGcav,se :tn this case the propulsIon u::1i t is susl'(;:ndc.,cl qn:ite n t; /"lr the op0ning of the nozzle and C 8,1).E:,':?-:-J LYl e m·: ,yi1l1'.un deflect:i.oll of the jot . UHtural l y , the de:form2,t lcn of the jet also ckpend:-j u ';)on the force o f tho I~o_ ulsjon ~e t and the incl i nation of t he pro ­pulsion un it .

The sim;) J e st method t o eli1Jl:lnLte tl':I.C d i stu:('b anc '':; s i ndi c at ed Cl,1)ove is to 8E.tE;ud thG meD. su.rGment t o z /dA

values of such rna:nitude as to guara::1 t ~ e t he non8.J pe ar ­arice o f t"tlt3 (If:scJ' ~:.belj : .. f .f0ct . 11'11118 O ':'1 (~ cle tf?; ],lHlirles tl1.0 aSY;1'ptotes "'I1L1 C 'J i, ; r' lJ, tiH) rl b ,,: us e d as zurCl l in8 . rl'hls mode of r:t'ly,;eduro r:orL:f::d 1'011a;-)lJ in ,-., '1(; 1".'1 C i:~ S8 .

'rile rr:.f; tIc,Gel 'i f 8 S re "[d(':)' 0 d ::'110~_'e d.~, ff ::"c u 1 t 'b y '110 [ttlur :Lng tho l1cr~ 2,ti \[8 z V{, lUG :.3 ( 8.3 i n dic8.t8d abov:,; ) :i. n a V</8:y

differ G I ~ from t he one us ud in ~uac~rinG th~ pos itive value s ; i t wa s 8, 5_lilE'd at rodu,cir<; thc") distul'b a y:ce caus <j d by t',1e cus pciw io n ( ) f ~~h c. pj:,opu l~) lon unit . It r:l8.:r b e the cas s t::2 t t ljG C 1.r:' \TC S ;1 0 nOG ,je:l.n cot z = O. A me El.n

v Cllue \VDS u'::)Q i1') the 6vhluat ion .

So f' a~r t tl8 l") (:su lt s V'fe I~ e c1isCll~secl 8.3 t11C :;" ~;VGre

obtaine d fo1' thd 8jJGci.:l l ar>:r8iig<::,:r10:;'i tS . l'!o'V \I; e f3ti.L:, 1 1 tr y t o find y'ell1tJ. ons 'Nhiefl wI ll Il iake it pO~J3iblE:., to ciraw conclunic'Ds us t o ony 3.rI'a'(! ,[~cJ1!G nt . To th:1.s cond tbe specif i c condi tions S ave t o'be dllminate d from the r e sult s of t h e experiments .

" T},'.I, f,,: d :: ,f,"_, ~1 _' "1.' t -_i ,-'"'n orc.> t'h_(j' , c a,' ',,- , 1 " 1 .J. ' - } l!, Vc..:.,Ll18 t;l V0n 13.)0'1(; COYlG8. 1 ns

alr 0 ad~r c e r ta j n ,-:-; '::::1:el' a1:i z at i ('In::3 0 I" i r st of a ll t·~lC d.i:l),(tC ter of t hn jE, t d A 'i>l8.S -Lntrod:,lC c d 8.S c-l, I' d/0:: r GnC G Q'1LlP ti.t y ; her e by the 8)Rn of the wine w2 s G li~iTIated . Th3 bp on wa s for 08.C'.l.l ca :3C t 3.c J_tly f; ,<~SlJ.) iL- d GO ;) 0 so If:lrge 2 3 tu C.,)1'il­

pJJ:; t; e J.y COVOl' tlw region of Jnt.':; I' !'c rE'nce. As a Second s tep t~i8 ,vine c1l.oY'i..'l 1 was I ' c,':n r)iTc c:1 1y? st: l ect 5.nG (tp, x L at) l ' 8 .fu:l':(!11CC ar· ~J a. TIte: tl1.1 et:naso (":t" tIle v\rirl~ d [:.n.d unO. the rat-Lo Vi/Va u,l"c1 d l .rf ~ I":'ncG VA - v

O' I' c ;:: pectively,

were ~['ocogn i zed as the Y:lC)st in~p ()pt!ln G re;;.aining pUl'anet0rs .

c ~:- was assurned to be proporti.on8.1 to vA - Vo 01' a

v;/vo - 1 ; thi.s proportion i s physi c ally plausible f or

the mix :Lng effe ct only, not .for the pote~-Lti3.1 flow" The r eFl£:t i nLl1g qualltity

",\T '0

" C 0:

a '1 c...

A

r:.:. v d x 2'. 0 A

/V,\ \ L I , .. _.:: - 1./) \v o

will be a fi.:1.11CUOn of t.~Le thtc>:ness of the wing d al1l1 first o! all, based on cons irterablors of potential theory, 8. f'U'[l~"I' -I' c"' n ,,+' ;"[:'" -1" 8.' _Ll )' n (,/7 PI· c.l~e <ol "~ ,' ,:"l_1 <:)"°"1."118'-'1 f-~ .. .._ I. ..... <..I -'- ,'. I ...... ...L 'J .L ,..., ~~ ' . _, .~ l.; 0 r:. \..J _ c.:;t _ ,-,.~ • ~ v ~ ..... "- ~) .(. ~. ~...... ........

1 l' '''1 c· 5_'1~ c'l " "12,') rl (··n c ',-- P " 'e'i-. 'nr.·; ~' ;'I'lO~" 8r.'·1·" I' 8 ·1 - ]' 0 eye' e'1 /~ _ .1..... . . ._~ ,._. ,I .... _ •• / .... Y 0 v'~._ L __ '- .1. _ -- -. V lJ . ..... 1.. / vI.. :i

( t: ' . 1 " i 1 . j, ~ • , .D -L 1 " ) 1 • - 1 In]_ c ,.'~nE::H-; S 01 ~ -)8 \'nngL(tlB.me-cer OJ. l,ile ;je -c a .. _80 WJ._J.. 3)PC8.L'': for It is t~ asil7l concej.va:)le that a thln jet wiI l have l es .s .influence th s.n a jet of ere-at extent as cornparcd t o the tLlckness of the iiFin3 ' ·'Ne d.8tEwE11ned. the kine.. of thL') dellendency empir ically , -using the f1Elxil!mm values cal'l~:- ' It bee-omes obvi cn.s t11[,'(; elidA alEO ";.ri l1s.pl)(;8.r i n line ar de ~:;ende:I'lcy , a nd that, the m8.xil1lii in a ll ni8 c; sure ­ments can be r eproduced c,rna z111g ly 'Ne1 1 IJy the: relation

c E,m" = 1. 10 (2

as sb.ovVrl :tnf'iguI'o ] O. 'lJ:ero.fo:ce, the value of

th ~s en d, divlde~ the m8a~urQd ~. '.~

c dn~ • F iE~l'rpe 1 0 8110\J'13 t118.t l'1.ere also it is l)Cssib l e to dT1i-.lVl

a lUJ.Lform ClH'\ie thl' OU7,l1 al l the expc.' r ir!1c,nt a l po .inti::l. The dispersi on is, in the-main , unsysteuatic and the points with the l areest di spers ~oD on the cV8ra~e may be attrJbuted t') tl1e tV1C 81n211 vslues VA/Va = ;2 .05 and

v "/V = 1.85 0 the:;,"' e tl-!E3 inaccm' 8.cle s of me asurement i .n ~ a ,

t his c;raph arG , quit.e naturally , mos t noticeable . (~l'hese

8

Vallle s are obt::1in the f·1.cure 11 u

civen wi.tll ~ross0d out s i gnso ) approximate curves r epres8nto d

NAC A Tl'.1 No . 110~_

In t h is way we g:::aphically in

'rh8 se Ci.u've s , togetbe r with the formula for c -1:. {lIn

may be used as a goclet approximLtton in the general case . 'rhe l'egion of va l idity w:L ll ~e gi vell by ~~bout

e'L/dA.~ 1

hovr0ver , the liml ts of the re C ~lon \;Jere not ye t acz~urately

defined . In 11mi U.ng Ple reJic;n of x/J. F. i t must be

pointed out that t he ap~roximation was se t u p mainly for the case where the po Lenti a 1 core i:ol not ye t cO;'n:o l e te ly reduced so tho.t still the full Et{1l0unt ( vf-.. - vo ) arJpear s

as 've locit y difference . For creater c1 tlr i.ty the spreading of t h e j e t is represented graphically in f i gure 12 .

'The mE;asurement.s for tr eated specially because d i v ided the measm"'cd C a>;:-

s t atic conditions have to be of va = O. In this c ass we

valne s by the expression

/ d \ . . 0 ~ ~ ,.'~ d.

f ( d, d f~ ' 7, ) :..~ 1. 10 c: - ",-- I ':-Cl;\ J 7)

\ H I

it bc c ame obvious that the measl.lx'oments on the thr el'~ win~s a pprox i ma te l y coincide again . The re sulting ap proximate c urves are indicated III f:l.gure 11. Devi:.:,- ti.ons fro in the C0111'S8 of tlle (:"l!.1'vo 8.p~) (:; ar at x/i.-. ::: 8 WheI'G the

,Ii

potontial coro has blr c ady be on :-e e duced to ZG1'Q (c ompare (5 ) ).

':Ph t s E-JVa luE,d~ ion doe s pot .inc Inde the c ase of -.rH\,wd f l ow since the r e l ations thcro 81'e no t ye t suffic i ent l y cl er:1.:fied because of the unknovlfll c ourse of t ho j e t. J:i'l'J."th e1' inve st i gations i n this respect are i n tended .

NACA T~ 'l No g 110!j_

rrhe mlJ.tl1al l nf l tl.ence of a j et px'odncGd by a pro­puls ion unit and a n3arby wing w~s investigated. The te~;t3 conc ::3 I'Ged mainly Ull~ ee different vd.nGs . The se wi n gs ·'i.' e 1'e sus pende d in s u ell 8. nwnner t.bat triey )1ud pI' BC t ie i'.,lly no 11ft wi. (,hout the ir:.:f.' lu.e ne e of the :i e t; t he inter f ej.'ence lift ,~ as "He c' su.:-e ed . S"he ~ii O ::~ t impor t ant qualtit:i. e8 of influence c an ue c1r::)termiIJ(::: d fl~om tlle resul ts . rj'lley a I'e , ap[T t from t i..1u geOlriet:cica l of -[":;h8 vdng t oW :J.l'd the jet., t he ,,- e ~~oc.1 ty r at i 0

p osit i on v Alvo

the c b.ord 7., of the w ~. nf. and the th5.c:~ne 3 8 of t he ~,'.r _·i.l'lg. d· f' .:)'.L~ ':1- 1) l-' tl" .1-1' e ," a 'i-. ~ () s u·' /7 a ':'--1" rl//d ' • :J..l.. \ • ' ." .... l l.J .'.." -- -.' .1. \. / J .l. .• \. '- Ii

( ~AJat i o'n ~o t tlP ~~8~G'~er o· f the ~Qt ) 8 :t~e o"l~ 4~pnl' t ance .L . J . _ _ L; _ --" .J -'- ~ L, l,. 1 __ _.. d '-I . . .J ..... I.:..... . _ 0

Appro:':.ill~& t e fOr ~iT\..1J.as for th e ] 1:['!; t o be e.x::x;cted we re give n. A fev! s hort t est s t reat the case of E! ppopu lslol1 unit 1n ya-,ved flow. ACCol·d.i..:ng t o the I' csul ts it 1s P08s:1.I)1.e to i ·i.x, for :i nsta:.lc8 , the ;Josl tion of a t8.i l unl t in s uell 2, "'13.:T tlla t th '-~ infl1l6nCe in tho c [c s e of s tra1 2h t f low i:;:; only TJ6r"'J :: 11 ~~h t. j'To t :l.ce able [(lleL

unwE'J lcon~e effe cts are to :J8 (;xpected onl y -"hen the j o t is pointed directly at t he wing 0r is tan~0nt to it . Ther elorco , ,"'or a p roj ("; ct , l.c;lOvdeLLcc of tlle GOUrfie of' the j e t uI1C~el' a8 n~any dLfferent fl1.~;ht condi t ions as poss:Lb le should be e~dphas i:;;ed . 'l'he :3Q qu,j s tiO ;1S [:\l' ~; also e spec ially i mportant w:lth l'c~: p e(: t to U16 ):L'oulcm tJ'eotscl here .• because t he spr (~adin[ Ci f the j e t depc;.1ds cons :i.de J.'E ~)lJ upon the fOrIa o f tr~ e f:l.J l e t 1'02 the :1. IW tallat Ion co,nd ul)on t h e !;03sibLl:l.ty of Ll 8u.ffl r;ient vG nt1.1ation from a ll sides . rrh:t:J delJEmdency i8 e8pe cJ. 8 11y obvious -V'rhc:rG the Pl'o p-l.l.lsion uni t ).laS 1Ju (;n LUltallod OIl the outside; .

Trans12t e d by Marv L. Mahler c .-

Na t:1. onE l A.iv1 s or y Co:tnmi t t ee for i~OI'01} aEt 1 c s

10 liT . C ' m~[ "''' 11 01 )\11 A .LlI·! L')O . _ .. _ : /-

VI. BIl3LIOG3A.JEY

L P 0 rtl~C.en ~ The,)l'Je d83 TrEl,cf J.'lijelproJ':i. les .ln UCl' j'j':-;,Cl'. bEl~:' s cha f t s V'Ul~.gb '11'I .er t ~ c f) 8;nt(h'U8lc~lnd3ran!:.;en ( S tJ.' ahl-· u.ncl V;:l Dds cha t 1~ en .11 'i, t 1-\.0 Cilh:, ,;I{t):-:-- of:i.1) , .J nhr :)l;:'C1:. cI e:e ClE' u i:; 3 cteil Lt.' f t f' eJ.)"lr t f ur s C11Ul:t:; 1 (,, 7 CI Q T l) P f' f _.' __ / , >.J , _ , . v '.

'; ; ~.Ld'{3.1·1.hJ "f18 ::l Sl.Hlh':,,~n ti.b''n' dG'!. V'I:1 nds (' lis. Lt nne 1 nt' Ius s ~ .... . .

auf HeclJ.tcc ;~ tJ'8.(!;.fluCe:L lLl t s:,T ,::.reGJ' isc'hol'i\ Pro.fll • . J &]:11' b-' l c l1 j . e.~' (le; ': 1. b :::~ e;l e j 1 ~L1J.r ~;.f:) ttl !II l~ .f ' (.)1 1 s C1'"l1lYl.g

19!.J,O 9 :3. I IdJ.~ ff.

2 . \'. ~;~olJr.s0 :r L: V C1~[{allG6 •

i 4 . H. 3~Qb18wbki: L:lllr r_~r~fjo)~ le d.8 .i' 1;.118~v]~sltuJl?-~ e1:")'(; S Ul :tS

1 . .(1), 3 C:':'6t'f;nr:1un f:e (dG n ,StrahlCE:: . I. 'J'eil: e ~.Jle:~~ J)l'tC2 se tTY 8003 .

r- D ,or" l' c< t .... ~ r ' " J • 1 . '" d ···h 'llt ff: 3' I')C .... "( • ') .. • I,,-U C ·lG'·.~ldI.'.n : ' .J ,r (:I n .' .. c!.1:·, S u~:' E'; J. C U:1g J,n v~ ". n .... nu __ 6 , )

6. H . i3a'u '3rlE1 : U~1'LCrSl.H;:bun .'~e n a '''1 dem L:()(~ell (;j~1f)8 ~:;tr t:l:l.ltI'i .3b~!c1'~c8r~ j , ln '.i:lrldkr:lm. l, I . 'I'(,j,lbeJ' lc.ht: :5 - Ko:n.gonen tonme S 81.u"ge: 1 E.n e 11'.,.6 1' Str alllf.~onde :;' • TJlvL 3009 D

NACA TM

N

o. 1

10

4

Fig

. 1

..

)C

+

I I

I I I

I I

<

t

I I

4-'

$:l .,.-i

I 0

I p.,

. (])

r--i

I t)

I~

$:l Q

)

s.... (])

:::I

I ~

bD

l:::i (])

• ..-j

"H

r:r..

I (])

I ~

I I

I I

NO

... t

Fig

. 2

NACA TM

N

o. 1104

~

-1

)

Ii W

9L

'I ~

) 3

NO

O

11 X3

I

H I

I (!)

I z

I -3=

0 I

0 I

I I

I ro

I I

" I

I I

Cit'

ILl I

I", iN x

I ~~\1pJ..--

I I-z

'I ' I

w

l-I

::E 0

w

>

I (!)

I -0.. I

I z

I , I I

<t

~o::._o

(0

I I

0:::

~

I I

I I

I 0::: <

t

, C

\l

I \-

F--'

I I

I I-00 W

>

I-

wO

S'P

<w

O'1

I

31

ZZ

0N

-......

--

O.8r- ~ i (lSI

4111 t \

11 Ii f~ QS

Figure 3.

Wing .I

..1- 0.16; 2.:: 0.69; ..!. ~ - dA dA

43

0\ VA/Vo = 4.0 + " " = 3.0

• " " :: 2.5 b. " II :: 2.05 )(. " " :: 1.85 0 " II :: 0.77

lUI ! I I \ I -I

::llzt:\I, \1 I I 1

~z/~

z > C":l > >-3 ::s: z 0

..... ..... 0 ,j::>.

"%J 1-"

oq

(J:I

Ql~1 --~--~~~~--~--~

<1.6 <:8,'"

I , t '1 - I'

c,,,1 1[\ ~

0.3\ {lA" I" I

<1.71 I .

]e;::s:s

0.11 Il,';\\ ~

-OIL I _..1-_1...---1.._-'----1'-.......

Figure 4.

WingTI

.iL",,0.10; t

.A. ... 0.25; t= 2.5 dA A

.. VA/Vo = 4.0

... " " = 3.0 .. tI It :: 2.5 I.t. " " = 2.05 ~ " It -= 1. 80 C " " ': 0.77

II Ii 1'dA>81 I~ I

'':1;1 1-'-

OQ . ~

z > C':l > 0-3 ::s: z o

I-' I-' o ~

0.7. X/d",..,l

eQ d~-------t ~------:==

0.'1 lb--

o.3m~t-+-+---J--

0.611---4--+-

75?f?::z' I IJ:!:..'~ 3 o ct.c:::> t "=--'ZIJ. A

0.1

0.6 c.C

t 0.'1

Q3

0.2.

0.1

0 -Z/JA ~

07-. ---T--~--'---'---lr--I xfd~=2

Q6 dAex=t-=-=..:=--=-----c,.. - 1------r~-+~~~ ~ Q,~~~~---+-~~-+---~

O'31~.r~~~~--~---+--~

O'2Hrn~~~.-+-~~-+---~

01

O~~~~~~~~-J ~

47

Wing .:n::c .(

d 0.09,' JL - O. 16,' -:.1. 8 -~ a. - d Jt A A

• VJlVO': 4.0

+ " " = 3.0 • " " = 2.5 6 " " = 2.05 x " " = 1.85 o " " & 0.77

Qll -i

~6 xfdA~

d I~:,; - --:-,--:1 Q6 I ' I • "j',;;;,;l:=:---ut--=.j r ctl

-I o.¥

Q3

~2

0.1

0

> • ., :~~I.a.1 II I

2-_z/tJA

Figure 5.

~-=~; -J I -t---all 1

z » (".)

» 0-3 ::s: z o

f-' f-' o ~

'%) ~.

OQ

CJ'I

Fi g. 6

"'3 r---~--~---r Wing I

..!!..: ° . 1 6 ;.2.: ° • 6 9 ; l d ~

1i.~1+1--+..l. = ." 3

opz. I---+-+-

d A

jAl~::"::=: : . ~~-------

-~

u.~~---r---'r-----------------,

O,021---1fft-Ir---1

(J*

t

Wing n .!!.. Q .l 0;~S O .26 ; ~ d A

..!.. = 2011 d A

J~-5f~:::' :: ~'1t ------

~

o.~1 Ht--f--\-~~+\--+---+--i

OL---~~~~--~~~--~ _Z}dA 3

NACA TM No. 1104

Measurements f or . static conditions

0 X/dA = 1 <Ii - 2 -• = 4

• = 6 + = 8

Wing In

d_ O . 0 8;!-:O.16 ;

001. t----+----I i - d A . .;;:. ;. 1. 8 .

l

4i

t Gl-----<1,.. __ =.-=-

1:1

'b

Figur e 6 .

NACA TM

N

p. 1104

r ---J I

I ...

I I

I I

I I

col I

<i:1)( ~I

I ~ I

I I

I I

I

. C\l II

~I'd~ ~~fi i I I

Fi g

. 7

I L ali I-+-- ~A.z'1 >tOI) 4Qt,== .--

I 1 I IT:, +L ~ I '!3

I I I o.ll--~~R--l1---I I I I OJ

2 I -I ~':i~/l~F/dA L_

'1\~W ~\\ /1 i)

IIII~VII ~ II I I I I :'l....--....JI L...--.....II--i....--L.--II

Wing:a:

d _o.10; d _0.25,R.2.5 -- -- ,-It dA dA

--,

~ Q'e- I Eex:=r: -l I 'I • - ----: J E I I osr- fl\ I 'iL=r-'lt1"A~ _ I

1 - ·CIt VI\ \_ _ - '4 I I r I J-o.~ I Y~.\ _

r I ~Q2r .z-~ k~ _ J I r~~~ ~f1.1 1 .~'"

t-,- i-z~ 1 J '\ V J 1 2 r i \1\\'\ _ I ~' r j ~ _

~ ~~- -O":-\-i A _

r A\ J ' 1_. _ ,- \ - -j ~ -I!JI"" I I 1 I [I 1 -L oA-

~:6e Figure 8.

"Xl' i-"

OQ

co

2:: :> n :>

~ 3:

2:: o

.....

..... o ,j::>.

NA

CA

TM

No.

11

04

F

i g.

9

,.,

. I lI.I/ -~')//J

t N

i:___

vV

\ t ~~!·~~-'Ir

1\ , '

~~

• r--I--'

' ~ t"-+

t--, '

..... ::""''-r--

10... t---~.~

I-,

: I-'"

~~~8.. ~r>

~4"'~ i/

. , 16

~

-~

~+--

• a

~

g lk~~ ;;::.

,.. G

O

er-a -

N

a 0

ci

...-! . ...-ci

c::i ci

..:. ~

... "1

:1_

I

I I

I I

I

~-

-cc

~/

. ~ )<

N

I llJi V

:J

c-

h Li

/ ~

I I

,~

Hr.t=

.r-->

--/LV - I I

I -t

VV

' r1

j '-~E~r-v/t/ I----! i

I'-~

/, \

~ i I

....... ::-

t--t--

, t:J

"J +

... ~

v7 'r'

~~/ ,,)V

+

..... .

CIQ ...

~

cs 0

a a

cs • ~ ~ .$.-~~

: ;

Q

1:1 cs

o·

~ ~4

, -.:

I .~

• ",

-

~

'0

.,,:.: -;;-

-

, 1-, /.

1.0

0.9

0.8 c 0

--L-c 0

a a

t O.S

0.«1

o:~

0.1

0.1

o

~--~~'~Jf'+·'~'\~\\'--~--~~~~--r---t---t---1 /// \\~\ !h' \l~\--+---+---i---~---r--~---1

I I~, ,_ Approxlaate curve I ltv, I,

:L 1\\ '~ X/d",=l.

'l · \\l\\. J \~" " ~

.f, ,,, 'k. , i"'-.. g ......

I., ~ ... ~,.. ... L ! ............ 0

,(/ f\' r ,d.., /' i', 'I, ~ z/dA 2.0 z5

0 4 ' /.1 y \ \ 1

c'o i ,il" \!\ \ a

~ ~ I,' " \ I'~ Apl,roxhate curVf!

ca."",

3 t/O~k/

"ft /l-r:-. " " /"-10%

B(2.=t>t /~ ,," ~~:/

• " IAPprox. tor.ula

~. C;' ... =I.I«1:j).1:(III1/u,,-1) . ' A _

" iB'~ Re~lon ot valldlt,y

lif X~A!fo f=- t;../lb -= If

V Id/~~ I

I'

o 1 2. 3 VA "

Yo

• Jl~ -r+-~~~i"":'"""""--.---.r----r----r----1 t&: tIt' I '\ 1\" ~/.tA=8 Compari son of the approximate curves

o

IJ:u p e. \ '\ '

~'/ ~, 0.'3, " , ,[ t"..'~ 7 1:::-:t---

V r i 1.5 1.0 1.5 - Z/dA, 2.5

W~ng

. 0 I A IT

• III

Figure 10.

wi th test values

d/dA d/~ 0.69 0.16 0.25 0.10 0 '.16 0.09

'%J ~.

OQ

...... o

z » (')

» ~ ~

z 0

......

...... 0 ~

NACA TM No. 1104

Q:JIH-+--i--

C .:0 a

o

alo

~ (d.da·~)

05

J[

Approxt ... te curves

d c " .. 1. 1 8 ( 2 --d ) "II A t

/.0 IS

0.08 -jF--+-:2~i..¥~~-

Figure

Fig. 11

Spread i ng ' of the Je~

I ..,'IP

-1.4 -1.2 -1.0 -0.8 -0.6 -0. 4 -0.2

-1. 4 - 1.2 -1. 0 -0 .8 -0.6 - 0.4 -0.2

..

't '4 I ~ :)(/dA = ~ -1--- 4---1

P -P to t 0

:t:-n 2 2-

0\ 6 .. e For stati c conditions

t 1~2 ~--~-~I~~~~;tl----~--~--~~ o 0.2 0.4 0 . 6 0.8 -- Z/dA 1.4

Ptot-P o 9

L YA2

f 0.2

o 0.2 0.4 0.6 0.8 -- Z/d A 1.4

Figure 12.

">::J 1-"

OQ

...... ~

z > o > 1-3 :s: Z o

I-' ...... o ,p.