NASA NACA-TR-1386-1958 Investigation of the drag of various axially symmetric nose shapes of fineness ratio 3 for Mach numbers from 1 24 to 7 4《当马赫数为1 24至7 4时 长细比为多种轴向对称机头形状的阻力研究》.pdf
《NASA NACA-TR-1386-1958 Investigation of the drag of various axially symmetric nose shapes of fineness ratio 3 for Mach numbers from 1 24 to 7 4《当马赫数为1 24至7 4时 长细比为多种轴向对称机头形状的阻力研究》.pdf》由会员分享,可在线阅读,更多相关《NASA NACA-TR-1386-1958 Investigation of the drag of various axially symmetric nose shapes of fineness ratio 3 for Mach numbers from 1 24 to 7 4《当马赫数为1 24至7 4时 长细比为多种轴向对称机头形状的阻力研究》.pdf(18页珍藏版)》请在麦多课文档分享上搜索。
1、REPORT 1386INVESTIGATION OF THE DRAG OF VARIOUS AXIALLY SYMMETRIC NOSE SHAPES OF FINENESSRATIO 3 FOR MACH NUMBERS FROM 1.24 TO 7.4 _By _l)alcD _,. PF:ItKf,_, I,f.;LAXt)H. JORCIEN_I.;N, and,_Mo_ (L _oM_ri.:itSUMMARY/)rag m_a._umme,t._ har_ l)_,ll made at =ero a,gle q atlach:l.r a ._,_._ ;_ ,o.,v ,dml
2、._,_, 7l rood,4, in-r a ._erh_,q/hf.,i._,he,i-(all g b/uated cortex uere (t/.vo abtai.ed. 7tie .l(Ich tl#llft#ll atldl;eynohl,_ numDr ranges (_ the te._! wt.re 1.2_ to 7.uI atve a.llach nl,mb_r lilil(k. (l(f._) iitieikhl_ ;111(I I,(_hiiid II. J()lg_,IIs(,ll, 1!i,2, :lll(l t_l(, I(l“,(,:l) lli _.ligl
3、l_ll;ill_llilii _)21113 t)_, 7iIlll)ii (. 71)liillICl“ _ir_|I irJi(_ a., Stark, 19D2.52G597 G(I “,0 23 1Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1232 REPORT t386 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICSintegral equation as the basis for the
4、se derivations, theapparently uimecessary ,eL simplifying assumption ofzmo slope of the meridian at the base itas been inposed.This restriction is pointed out, by Ward in reference 5,wherein lle shows that his more genera| expression for wavedrag reduces to that obtained by yon I(firmfin for the spe
5、(ialcase of a )o(13 having zero slope at, (he)as(. In a lat(,rpaper (ref. 6) Ferrari developed _).minimum drag nose shapefor a given hnglh and diameter which has a finite slope oftle Ill)rid)an at, the )as(:. For the high supersonic Nlachnutnber raDge, minimum drag shapes based upon Newtonslaw of rc
6、sistamc have been derived l)y Eggers, Itcsnikoff,and Dennis (v(,f. 71). These shal)eS differ appreciably fromcomparable optimum shapes fi)v low supersonic Nla(hnumbers, although the theoretical optimum shapes i. bothinstances have blunt noses when the length is fixe(i a.d sharpnoses when the h,ngth
7、is allowed (o vary.Due (o the basic assumptions in (he derivation of th(,K_hrm:m integral eq_,ation, it may be expected that timshapes result ing fiom the use of this equal)on arc theoreticallyoptimum from a minimum drag standl)oin( only for largefineness ratios and low supm.sonic Math numbers. It)
8、con-trast, l!w shapes resulting from the Newtonian theory maybe expected to be optimum only tit high supe)sonic Mathmmfl)ers. Iowevcr, fi)r low fineness ralio shapes at moder-ate Math mmfl)ers, it is impossibh, to say q priori which of(h(: (heoretically opt immn shapes will have the lesser wavedrag,
9、 or in fact if (:iwr of Abe t twories is capldle of predictingthe east-(lrag protile. One of (he purposes of the presentinvestigation is, th(refore, 1o coral)are the experin,_n(aldrags of these t he(wet)tally opt)reran slmpcs and of ot her morecommon profih,s for an intermediate fitwness ratio over
10、awide Math m, mbev range. To this end n sezies of /inencssratio 3 models of these theoretically optimum shapes havebeen tested in the Math mHnber range from 1,24 to 3.67.SYMBOLSA model base tlrea, sq iu.(_, total drag (o(ti(ie)l(, ttal-(l!_agqA(“he fotedra_ (,o(qIici(,)tt bets(,() () It+is(: ttJt,a,
11、t(!al ,hn_ !)+!s2: ,it_gqA,)(%, for)drag cot,filch,at based on volume t() tI)c !_ l)ow(w,total drag I)_s(, drngq I2:“0._iv(, (z_ig(+w w_Ivc (ha_ (o(qihi(,nl, - - q:ld h(,misl)lw.(, (li.me(,v, it).1) mo(M bast. (li)mwt(.r.iK simib)vi(y /)ara)ne(,r, 1,)L mod(l hq)_(b in.11/tp_pptp_q1Rl“.VOLT0free-stre
12、am .Math lllllnb(Tpressure (oeflir wnying (he test section Nach number.For (he tests in (he supersonic free-flight tunnel (,he ntod(,lswet(, launched front a smooth-bore 2()mn-t gun, and w(,vesupl)or(,ed in the gun )y plastie sabots. Separation of (h(,model from the sabot was achieved by a muzzle co
13、nstri(tio)lwhich r(,tarded the sabot and allowed the model to provc(,lh) fiee flight throtl the test section of the wind t.)m(,I.A move JOf_ivq,n h,n_lh and I)_l_(,di:_met(,t.lh( measnr(,d t()lal (ha F _ll(1 Imse )r(,_sm_ drag. Ieca, useof tim Ol)er_tting (hara(hwisli(,s of tim Immel_, il was nol)os
14、sihlc Io nminlain a (onshlnl lllO(- llilllliill_ (Ifltxt-, in llw .me_ _qll)ersl)nic free ili_ht wiml tram.l,A_r- otf operohon J r i- / I J8hmgitu(limfl pressure distril)ution al each :I( in(r(,m_,nt iu(iremnfcr0ntial an_h, was ()l)l_ti_,(l. The r.,sullin_ )ressm_,(,lfli(i_lHS al (tuh lonFitudimfl s
15、llilimlw,r(, :_vlraF(d I.othtii_ I1., valu(,s lW,s_,nte(l.Free-flight wind tunnel.- Wilh nn air Ibm lhrough lhewi.d Immcl, M_h m_ml)_,rs varMl fr()m .2 to 4.9, (hpm_d-ing on the model hmnchi_g velo(4|y. lt_i_ (.n(tiliml isrcfl,rr_,d to as “air off.“ l%nohls nulnh.(,r vari(,.i lim,.rl_ith hlach mmfl)
16、(,r from 1.0(10 6 h)3.3(I() _, as shown i_lligme 3. Wilh air flow (shdlislu,d in lh,wi.d tum(,l,rcl(wr(d h) as “air on,“ the (oml)incd v(,lo(iti_,s of lh( modealul Na(h numl(,r 2 fir stream, wilh the rldu(cd Sl)(,.d ()ts.un(I in tin, h,s( _(,(qio h l)rovid(,d lesl, Ma(.h numbers from3,8 to 7.4. In l
17、ifts regi(m of testing, llevnohls WUllll)er Wash(hl al)l)roxim_llely at 4(10 l)v controlling h,sl-s(,(lionstatic l)r(,ssurc. In llddition, some mod(,ls win(, tested a!al)lW(_xim;_le .(._his mmd)(,s of 3:4 1iF al .Xlach mml)(,r 6.Drag eo,_,llhi(,n( was obtained by r(,(rding tl., lim(,-dislan(.c histo
18、ry of (he ttighl of tim mod_,l wih the aid of a(hr()nograph _u.l fern sha,(lov.graph slalim_s al 5-fool inter-vals along tin, test se(tion. From thes. (labs., d_c(hrdio.was (.Oml)uted qnd (,).v(,rh(l to drag (oeflieicnt. Thisrel)orL inch(h,s only lhc data from mod!s which ha(I maxi-mum observed angl
19、es of attack of less Ibm 3 , sin(,r over tlt(,cnglh of (m(h mo(M t(,._te(l was less (ha)/ 0.01 f(w allt(,sI Math numl)(ws. lh(_ tnwertahlty in lhe Nla(h numl)erit a given point in flu, st, l(_llJtl iS 0.0(I;).lh(+ Inagnitu(h“ of the er(+(nI and the tnaximtmt deviation“+vtIS -I p(qc(qICTHEORETICAl, C
20、ONSII)ERATIONSWAVE DRAGWith the excel)lion of som(_ of the very bluntest, lnot(,_st)t( a ssutnl)tion thal (h( pressure on the cotd(mlsmfa(e _outl l)e the ,+)_m(as on a )oit)ted (.one of 11)( Still(,SOl)C. lh,n(, the l)rtssur( (1,ag n was o)tait_(+er. An alqwoxinml( expression forwhich is ._utticienl
21、ly accurate for the drll_ e_;limales is,+_ tan -_L2 (L/D) _ (,/I)2 t:+,)FOREI)RAG:llhlt_ of the foreJh_t.t,_,have |)t,(,n (mLculut( I)5“ the a(hlit iunof the (_st.inu_te(l or th(,oreti(al way(, drag and the t:teorcti(aa In (lh_ alq+li(at i,)_ (_fthis nlcthod a firsl-on(hl sohll iq)tLis tle(t“:q:lt i
22、y c)t)t:tine :it 0 :trig(, of al ta(.k.2L3,1.6Q 1.2Ea;d4C-,4oP tel tube pressure ,rot, ti ut_.lrlcompressrble pcre_hz rl_* ,_r, _2- _.wtont(rl ff_nor,. “ “ _COS “ r_t? .4 ._ .R i.OD_stonce lrorn 1he nose, A“(c) Model 6p, D- 1.00l“_(; uzt ,: I. ( on cht(|ed.skin-friction drag. _ince the sMn-friction
23、drag for laminar-boundaryAa.yer flow c.t_tributes so liHle to the foredrag, theinclusion of the small effeels of body shape and compressi-bility on 0_e sMn-friction drag was not considered justified.Therefore, the lamimu-sMn-fri(tion drag coefficients were cal-culated by the lasius fo,-mula for fiat
24、-plate incompressibh,boundt,y-layer flow (ref. 13). For the cstinmtes of the skin-frier,ion drag for hubuhml-l)oundary-htyer tlow, the bodyshape effects were neglected, but the effect of compressililitvwas ewduated by means of lhe Jnterpolalion formula of ref-erence 14 which is based ll)Oll ttlI ext
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