(Luận án tiến sĩ) ứng dụng phương pháp xoáy rời rạc để xác định và khảo sát các đặc tính khí động của cánh khí cụ bay trong dòng khí dưới âm luận án PTS cơ học2 02 02

1 DANH MUC CAC K ^ HIEU a Toe am dong khong nhieu, (m/s) b D6 dai dac tnmg, (m) b^.3^ Day eung dong trung binh c u a canh, ( m ) bjjj D a y cung ddu mtit canh, ( m ) b Day eung g6'c cua canh, ( m ) I Sai canh, (m) S Di6n tieh cua canh cu bay, (m^) p Mat d cua khong khi, (kg/m^) p A p sua't dong khi, (N/m^) q = ^ ^ D o n g ap, (N/m^) Y Luc nang eiia cu bay, (N) X L u c can chinh dien eiia cu bay, (N) Y c = — H6 sd lire nang eiia canh cu bay ^^ Cy D a o h a m h6 s6' luc nang theo goe t^n a Cy" Dao ham he so luc nang theo goe quay co^ m" Dao ham he so momen doc theo goe tan a mf Dao ham he so momen doc theo goe quay co^ m^' Dao ham he so momen ngang theo goe quay co^ M So Mach cua dong khong nhilu Re So Reynolds UQ van toe eiia dong khong nhieu dong, (m/s) YV Toe cam umg khong thu" nguyen X, y, z Toa cua mot di^m, (m) ^ = _ ; y] = i-; ^ zz — Toa khong thur nguyen cua mot diem, b b b ' * a Goe t&i, (do) p Goe trucrt canh, (d6) X Goe mui tSn canh, (do) r r= Cudng eiia xoay, (mVs) Cudng khong thii nguyer o The van toe, (mVs) m J' 's A= Do gian dai eiia canh Tl = D6 that eiia canh K MUCLUC DANH MUC CAC KY HIEU MUC LUC M6DAU CHUONG I: TONG QUAN CAC PHUONG PHAP XAC DEMH DAC TINH KHI DONG CUA CANH TRONG DONG DUCtt AM 1.1 He true toa d6 1.2 Canh eiia cu bay, cac tham so hinh hoc 1.3 Cac dac tinh dong eiia canh cu bay 12 1.4 T6ng quan cac phuofng phap xac dinh dac tinh dong cua canh cu bay dong dudri am 14 1.4.1 Phudng phap tinh toan ly thuyd't 14 1.4.2 Phudng phap thirc nghiem 16 1.4.3 Phuong phap vat ly dong 17 CHUtJNG H: T R U O N G VAN TOC CAM UNG Bdl CAC HE XOAY 18 TRONG DONG KHI DUCil AM 2.1 Trudng van toe cam ling boi doan xoay 18 2.2 van toe cam utig bcri he xoay xien hinh mong ngUa 21 2.3 van toe cam ling bcri xoay xien hinh mong ngua cac trudng hdp rieng 27 2.3.1 van toe cam utig bcri he xoay xien hinh mong ngua 27 goe x=0 2.3.2 Van toe cam utig bdi he xoay xien hinh mong ngua goe X'^O , y=0 28 • 2.4 Van tdc cam ung bcri mat phang xoay CHlTONG m: P H U O N G PHAP XOAY RClI RAC XAC DINH DAC 29 31 TINH KHI DONG CUA CANH KHI CU BAY TRONG DONG KHI f A DUOIAM 3.1 Dinh ly Giukovsky cho phSn tijf canh eo sai hihi han 31 3.2 Bai toan xac dinh cac dac tinh dong cua canh 34 3.3 Di^u ki6n bi6n 35 3.4 M6 hinh xoay 38 3.5 H^ phudng trinh xac dinh cudng d6 eiia eae xoay 44 3.6 Xac dinh eae dac tinh dong cua canh 46 3.7 Cac dac tinh dong eiia canh dong chiu nen 47 dudfi am CHUONG IV: KET QUA TINH TOAN VA KHAO SAT CAC DAC 50 TINH KHI DONG CUA CANH TOC Dp DU6l AM 4.1 Gidri thieu ehuong trinh xac dinh cac dao ham dong 50 eiia canh 4.2 Ki^m nghiSm hoi tu va chinh xac 51 4.2.1 D o h o i t u 51 4.2.2 Do chinh xac 57 4.3 So sanh vdi ket qua t h i nghiSm 6'ng thdi dong duciamOT-l 59 4.3.1 M6 ta thi nghiem 59 4.3.2 Che' d6 thdi va cac ket qua 60 4.4 Xac dinh va khao sat cac dac tinh dong cua canh 64 4.4.1 Su phan bo he so dao ham C "^ theo sai canh ^^ 4.4.2 Su phan bo ap sua't theo day cung cua canh 66 4.4.3 Su phu thu6c cac dao ham d6ng vao hinh dang ^ 69 cua canh 4.4.4 Su phu thuoc eae dao ham dong vao so M •K^TLUAN TAI LIEU THAM KHAO 80 85 MCJDAU Su d5i va nhip phat tri^n manh me cua nganh ky thuat Hang khong lu6n gan liin vdi nhflng tuu eiia Imh vue dong hoc, chuydn nghien curu cac qui luat ehuy^n dong cua eh^t va su tac dung tudng tac giua dong vdfi * vat chay bao noi chung va vol cac phSn tii cua cu bay noi rieng Cac luc tijr dong tac dung len b^ mat cua eae ph^n tijf cu bay nhu: canh, duoi, than khong nhihig ehi phu thuoc vao che bay dac trung bcri cac tham so nhu: van t6e, cao bay va cac goe xac dinh vi tri eiia cu bay so vcri dong ma eon phu thuoc vao hinh dang ben ngoai, kich thude cua timg phan tir cung nhu sir phoi tri chinh so e^u cu bay Canh cua eu bay bao gom canh nang va cac canh dieu khi^n Giong nhu cu bay, hinh dang eiia canh tren binh cung la mot cac yeu to anh hudng cd ban den cac dac tinh d6ng cua canh cac che d6 bay Chinh vi thd', xu hudtig hoan thien va cai tien cac dac tinh dong cua canh a mot dai r6ng thu6e cac ehS' bay, thucfng xua't phat tir nhung ket qua nghien curu ve sir thay d6i hinh dang ben ngoai cua canh Lich six phat tri^n eiia nganh hang khong cho tha'y rang eiing vofi su dori cua cac the he dong ecf hang khong tien tien, su thay ddi hinh dang ben ngoai cua canh tir canh diip den canh dofn c6 gian dai Idn, tien den canh c6 goe mui ten Icfn, gian dai nho va cuoi cung canh eo hinh dang phiic tap, thay ddi hinh hoc bay da lam thay ddi tiTng budfc ve chat eae dac tinh dong cua canh noi rieng va cua cu bay noi chung Nhihig tuu eiia llnh vuc nghien eun dong ly thuyet va thuc nghidm, cu the sir sang tao cua cac nha bac hoc ve cac phuong phap tinh toan va phuong phap xijf ly cac so lieu thuc nghiem da giai quyet cong nhieu bai toan ve hop ly va toi uu hoa hinh dang ben ngoai cua canh va cac phan tu khac eiia cu bay Ngay nay, linh vue nghien curu dong cac cu bay, mot hudng di mdi da va dang hinh thanh, la thuc nghiem tinh toan so tren eo so cac mo hinh toan hoc vdi su trcr giup hieu qua cua cac thiet bi cong nghe thong tin Hudng nghidn curu cho phep mot khoang thcri gian ngan eo th^ tinh toan m6t s6 ludng lorn cac phucmg an thig't ke dong cu bay Cac phucfng •phap dUde sijf dung phd bien thuc nghiem so hien la: - Doi vcfi mo hinh cu bay c6 th^ tieh, thu&ng diing phucfng phap panen Theo phudng phap nay, be mat cu bay dUde thay the bang nhieu eae panen phing, hinh chiJ nhat Viee tinh toan dude tien hanh doi vdri timg panen sau t6ng hofp lai PhUdng phap thuat toan phlJc tap , chinh xac khong cao ma khS'i lucmg tinh toan lai qua 1cm - Di don gian hoa qua trinh tinh toan, mo hinh tinh toan doi vofi cu bay cd thi tieh duoe thay the bang mo hinh mat nang mong Doi vdi loai mo hinh ton tai ph6 bien eo eae phucfng phap nhu: Phuong phap phSn tu huu han [16], phuong phap sai phan hiJu han [6], phuong phap xoay rcri rac [10], [11], [12], [13], [14] Trong cac phuomg phap neu tren , phucfng phap xoay r5i rac la phuofng phap duoe suf dung rong rai, c6 hieu qua va chinh xac cao De tai cua luan van ufng dung phuofng phap xoay rcri rac va sijf dung may tinh di xac dinh va khao sat eae dac tinh dong cua canh moi quan he phu thuoc vofi hinh dang ben ngoai eiia no d cac toe duori am • Luan van gom: Chuofng I: Tdng quan cac phucfng phap xac dinh dac tinh dong cua canh dong dudfi am Chucmg II: Trudfng van toe cam utig bcri cac he xoay dong dudi am Chuc^g III: Phucfng phap xoay rcri rac xac dinh cac dinh dac tinh dong cua canh dong dudi am Chucmg IV: Ket qua tinh toan va khao sat cac dac tinh dong cua canh cu bay Tac gia luan van xin chan bay to long biet ofn sau sac den cac thay va cac dong nghiep da tan tinh giup dd tac gia hoan cac noi dung cua luan van CHirONG I T N G QUAN CAC PHUONG PHAP XAC DINH DAC TINH KHI DONG CUA CANH TRONG DONG DUOl AM I 1.1 He true toa dp: Nghien cihi cac loai canh cua cu bay, thudng su dung he true toa lien ket hinh 1.1 He true toa OXYZ cd true OX hudng theo chieu ehuye'n dong eiia canh, true OY nlm mat phang doi xiing cua canh, true OZ hudng theo nira canh phai My>0 Hinh 1.1: He true toa xac dinh cac dac tinh dong canh cu bay Ky hieu: U^ - Vec tcf van toe tuyet doi, goe toa O, Q - Vec tcr van toe cua canh quay quanh cac true toa Cac thong so chuyen dong tuyet doi cua canh tren cac true eiia he true toa dong OXYZ: Uo = iU„,+jU„^ + kU„, Q = i Q, + jQy + kQ, (11) Vi tri eiia canh ddi vdi dong chay bao dac tnmg bang eae goe: Goe ta'n a va goe trucrt p Cac ph^n van toe U^ lien he vdi goe tifn a va goe trugt p: Uox = U^, cos a cos p U„y = - U„ sin a cos P (1.2) U,, = -U„sinp Khi xet bai toan chay bao canh eae cu bay khuon kh6 tuye'n tinh thi mdi lien he giiia eae ph^n van toe cua U^ vdi cac goe a va P cd dang: u„, = u (1.3) a = u, ^^ P = u 1.2 Canh cua khf cu bay, cac tham so hinh hoc: Canh cua cu bay phd bien la canh doi xiing tren binh c6 mep canh tnrdc va sau la nhihig doan thSng vdi goe mui ten khong d6i (hinh 1.2a) hoac la nhihig dudng thang gay khiic vdi goe miii ten thay d6i (hinh 1.2 b), hoac la nhiftig dudng cong (hinh 1.2 c) X Hinh 1.2a 10 Hinh 1.2b Hinh 1.2c Hinh 1.2 Cac dang canh tren binh Ky hieu: - sai canh, bg- Day cung goe canh, b^,^ - Day cung miit canh, Xi - Gdc mui ten mep canh sau canh, S - Dien tieh canh Dang canh tren binh xac dinh bang cac tham so dac trUng: Do gian dai X, that r\ va goe mui ten mep canh trude Xo(1.4) S - ^ Doi vdi canh cd mep canh trude la doan thang, thay d6i cac tham so X, T], Xo s^ nhan duoc nhieu dang canh tren binh khac Ky hieu b' - Day cung canh cua tie't dien Z theo sai canh va Xe gdc mui ten eiia ducmg thang chia day cung theo ti le tren hinh 1.2a Dai lucfng b' va tgXo xac dinh bang cac bieu thiic: (1.5) b' = b^ • Z(tgXo-tgXi) Hoac: b' (1.5') = i-z(i-n) tgXe=tgXo-2-^(1—)9 Hoac: tgXe=tg)Co- — ( ^ ) X r\-\-\ - ;z = 2z (1.6) (1.6) 73 Bang 4.20 X c;(xo=o°) c;(Xo=30°) c;(Xo=45°) c;(Xo=60'') 0.0000 0.0000 0.0000 0.0000 1.3815 1.4451 1.4689 1.4812 2.3067 2.4415 2.4559 2.3247 2.9640 3.1155 3.0446 2.6410 3.4483 3.5712 3.3857 2.7762 3.8165 3.8882 3.5964 2.8505 10 4.8094 4.6159 4.0182 i 10 Xn=0° Xn=45'' Hinh 4.23 74 Bang 4.21 X m : (Xo=0°) m: (Xo=30°) m; (X«=45'') m: (X«=60°) 0.0000 0.0000 0.0000 -0.2622 -0.2567 -0.2567 -0.2590 -0.5456 -0.4964 -0.4607 -0.4112 -0.7380 -0.6379 -0.5760 -0.5143 -0.8715 -0.7315 -0.6608 -0.6017 -0.9686 -0.8005 -0.7309 -0.6771 10 -1.2160 -1.0016 -0.9664 10 \ 0.2 0.4 •0.6 - 0.8 -1 - - 1.2 •1.4 J mz Xo==0° - Xo=3C)° Xo=6.=2.5 a cac so M=0.0; 0.2; 0.4, 0.6; 0.8 M6i quan he phu thu6c C ; =f(M) va m^ =f(M) cua hai loai canh khao sat xem tren cac hinh 4.30 va 4.31 Ket qua tfnh tieu cu khf dong cua canh h.nh chu nhat vdMlo gian dai ^1=1,2,4,5,10 xem bang 4.30 Moi quan ht phu thuoc giiJa X^ vdi so M xem tren hinh 4.32 Bang 4.27 M Cy 0.0 0.4 0.8 (X=l) C y (X=2) C ' (X=4) 1.5265 1.5455 1.6075 2.5740 2.6508 2.9576 3.7365 3.9226 4.8031 CV (X=5) C y a=10) 4.0832 4.3105 5.4350 4.9729 3226 7.245 y fto 7n 60 — 40 ' I- r—^"-•^— 3.0 20 ^ , 1 r -f ^ ^ T T I 0.0 • 0.1 X=l 0.2 -«i»^=2 0.3 0.4 0.5 - * X=4 Hinh 4.30 0,6 - - x=5 07 -^ 08 ?.= I0 09 M 81 Bang 4.28 S6'M 3[ ^ y Canh mui ten ^ y Canh tam giae 2.3531 2.4968 2.3652 2.5141 0.2 0.4 2.4032 2.5697 0.6 2.4739 2.6777 0.8 2.5942 2.8816 a y '^5 30 - ?*> t — 11 — • -H 20 15 10 0.5 - 0.0- 02 0.4 M 0.6 0.8 C2nh rrfii ten-•-CSnh tam giae Hinh 4.31 Bang 4.39 S6M m° Canh mui ten m' Canh tam giae -0.6831 -0.958 0.2 -0.6878 -0.9679 0.4 -0.7028 -1.0001 0.6 -0.7316 -1.0647 0.8 -0.7836 -1.1952 82 0.2 0.4 0.6 0.8 0.0 M -0.2 -0.4 -0.6 -0.8 -1.0 ' I -^t I k — -1.2 -1.4 m' Cdnh mui ifin -"-Cdnh lam gidc Hinh 4.32 Bang4.30 M X,iX=l) Xp (X=2) X ; (?i=4) %(X=5) X;.(>.= 10) 0.0 0.1717 0.2120 0.2332 0.2372 0.2445 0.4 0.1654 0.2080 0.2314 0.2358 0.2439 0.8 0.1326 0.1842 0.2192 0.2263 0.2396 M 83 Xac dinh va khao sat cac dac tinh dong cua canh la tru5ng hop cu th^ cua bai toan khao sat cac dac tinh dong cu bay V& di dat "Nghien curu ap dung phuong phap xoay rcri rac di xac dinh cac dac tfnh khf dong ciia canh dong khf du6i am" da duoc giai quye't Vdi nhung noi dung d^ cap, cung nhu voi nhung ke't qua tfnh toan thu nghiem, khao sat nh^n duac lu|n van CO thi khai quat nit nhung di^m chfnh sau: - Da tim hiiu, t6ng quan va he thong nhOng kien thiic v^ 1^ thuyet xoay dong khf dirng dudri am, dua cac bi^u thurc xac dinh cac ph^n van toe cam ling bdi he xoay xien hinh mong ngua dudi dang t6ng quat, lam ccf so d^ xay dung mo hinh tfnh toan cho cac loai canh co dang phiic lap Uen binh - Da nghien cihi utig dung phucfng phap xoay rdi rac dd xay dung ihuat toan va chuong trinh tfnh, chuong trinh hoa du lieu dau vao, kel qua dau tren ngon ngiJ C "'•' Chuong trinh tfnh cung nhu chuctng trinh hoa duoc cau tnic theo dang thuc don dam bao toe nhanh, thuan tien thao tac su dung - Da tiep can vdi ky thuat thu nghiem cac mo hinh canh dng ih6\ khf dong dudi am OT-1 cua vien ky thuat Phdng khdng - Khong quan Che lao, gia cdng mo hinh hai loai canh T chiic tien hanh va xiJf ly cac sd lieu thuc nghiem de xac dinh he sd luc nang cua hai loai canh d gia tri gdc tan khac vung tuyen tfnh - Cac ket qua tfnh toan va khao sat cac dac tfnh khf dong cua canh duoc kiim chihig bang ly thuyet va thuc nghiem Do chfnh xac kel qua cua chucmg trinh va phuong phap tfnh duoc danh gia tren co sd so sanh vdi ket qua ciia nhieu tac gia khac da duoc cdng bd cac cdng trinh (lO), [11|, |12|, |13| [14] va so sanh vdi ket qua thu nghiem Mi md hinh dng ih6\ khf ddng OT-1 Thuc te cho tha'y nhung ket qua tfnh toan va khao sat cd the ap dung irong cdng tac thiet ke tfnh toan khf ddng cac khf cu bay g 84 - Trdn CO sd mo hinh tfnh toan cua phuong phap xoay rdi rac, ket hop vdi ky nang sir dung may vi tfnh da ttoig budc tiep can va cdng viec ap dung phuong phap thuc nghiem sd tren may tfnh - Tren cO sd nhflng ket qua dat duoc hudng nghien cihi tiep theo dai nham giai quyet cac bai toan xac dinh va khao sat cac dac tfnh khf dong ciia canh pham vi phi tuyS'n, vdi cac tham sd chuydn dong cua canh cd tham sd Idn, cd tfnh den anh hudng bie'n dang dan hoi cua ke't c^u cung nhu lech cac t^m phu tren canh Xay dung thuat toan, chuong trinh hoan thien md hinh phdi tri khf ddng cua khf cu bay theo so dd dly du (than - canh- dudi) tren co sd dd khao sat duoc tac ddng qua lai cua cac trudng van tdc cam umg than, canh va dudi gay ra, hoan thien chuong trinh, tfnh toan bo dac tfnh khf ddng cua ca khf cu bay Luan van da hoan toan bo cac ndi dung dat de cuong dung thdi gian quy dinh t \ 85 TAI Lifeu THAM KHAO • Pham Ky Anh (1996), GJdj tfch so, Nxb Dai hoc T6ng hdp quoc gia Ha ndi Ha noi •2 Pham Van At (1995), Ky tham Mp trinh Ccasa va n^g cao Nxb Khoa hoc va Ky thuat Ha ndi NguySnHfluChf (1973), Cohocchi'tlong Aigdung Ik^ l , P h ^ d a i cuong, Nxb Dai hoc va Trung hoc chuyen nghiep Ha ndi Gerald Leblanc (1995), Turbo C Nxb Khoa hoc va Ky thuat Ha ndi Trgn Sy Phiet, Vu Duy Quang (1995), Thuy khf dong lire ky thu$t Tap I, II, Nxb Dai hoc va Trung hoc chuyen nghiep, Ha ndi Anderson J.D.Jr (1984), Fundamentals of Aerodynamics, McGrawHill, Nev\/York Anderson J.D (1990), Modern Compressible Flow, McGraw-Hill, 2"^ ed New York Ay6aKMpoB T.O., Be/iouepKOBCKMM C M , XenaHMKOB A.M., HMUJT M.M (1997), He/iMHeiiHafi reopufi Kptina n ee np^MOHeHi^fi, AjiMaTbi BeAP>KMUKMM E.Jl., Ay6oB B.C., PaAUwr A.H (^990), TeopufJ M npaKTMKa aapoAi^Hat^/iMHecKoro acnepMMeHta, H3A MAM, MocKBa 10 Be/iouepKOBCKMM C M (1965), ToHKafj necymsff noBepxHOcrb B /jossyKOBOM noTOKe raaa, HayKa, MocKBa 11 Be/iouepKOBCKMM C M , HMLUT M.M (1978), OrpbtBHoe 6e3orpbiBHoe odreKanm TOHKMX M KpbinbeB i^manbHoii XMMKOMCTbK), HayKa, MocKsa 12 BenouepKOBCKMfi C M , CKpunas B K (1975), AapoAi^HaMMHecKi^e npoMSBOflHbie /lerare/ibHoro annapara ^ Kpbina B M03ByK0B0M noTOKe raaa, HayKa, MocKBa 13 Be/iouepKOBCKMM C M {\9%^),Hi^cneHHu^SKcnepi^MeHTB ^ 86 npMtaiaMHOM aapoA^naMMKe, HayKa, MocKsa 14 BenouepKOBCKMti C M (^99Z)^^BMB nayKe, aB^aunH, ^M3HH^ MaiuMHocTpoeHMe, MocKBa 15 ByujyeB B.M., TaHneB O.M., /IOKTOB B.E HMUJT M.M., liJaMUiypMH A f l (1991), AapoMmaMMHecKafi KOMnoHOBKa ^ xapaKjepi/icrmtn /lerare/ibMbix annaparoa, MaujUHOCTpoeHne, MocKBa 16 BopA6beB H.O (1985), AspomnaMma Hecymm noBepxHOcrei^ B ycraHOBMBiueMCfi noroKe, HayKa, HoBOcudupcK 17 BoTflKOB B.A (1972), AspoAi^HaMMKa neTare/ibHbix annapawa M n/iMpaanma MX CMcreM, BBMA MM npoct) H.E.XyKOBCKoro MocKBa 18 rop/iMH C M (1970), ScnepMMeHTanbHa^aapoMexaHMKa, M3A "Bbicmafl LiJKO/ia", MocKsa 19 KojiecHMKOB r.A (1993), AapoMt^naMUKa /leTare/ibHbix annaparoB, MatiJMHOCTpoeHMe, MocKBa 20 KOHMH H E., KM6enb M A., Pose H B {^963),TeopuniHecKaff FMAPOMexaHMxa, v /, Oi/iaMaxrua 21 KpacHOB H.O (1971), AapoMt^HBMma, MocKsa 22 KpacHOB H.O., KouieBOM B.H., AaHnnoB A.H., SaxaneHKO B.H M Ap (1974), ripMKnaAHafi aspoMi^HaMma, "Bbicujafl ujKona", MocKBa 23 KpacHOB H.O (1981), OcHOBb/AapoAmaMMnecKoropacnera, AspoMi^HaMMKa ren spameHm, noBepxHOcreii, Hecymi^x i^ ynpaBJi^nou^m AapoA^HaMUxa nerare/ibHbix annaparoa, "BbiCLuaq ujKO/ia", MocKBa 24 MxMTapfiH A M (1981), AspoAMHa/^MKa, MamnHOCTpoeHne, MocKBa 25 HMLUT M.M (1999), "BbiHuc/inTe/ibbHafl aapoAHHaMUKa", \ 87 oemepoccMdCKMii HayHHO-rexHMHecKMii >KypHan "FloneT", crp 3-8 26.neTpoB K.n (1985), Aapo/xyiHaMi/iKa 9/7eMeHTOB nerajenhHhix annaparoB, MauiUHOCTpoeHne, MocKBa 27 nexyHMH A.H (1996), MeroMbi ti rexHi/ixa naMepeHMiinapaMerpoa raaoBoro noroKa, MaiuMHocTpoeHMe, MocKBa 28 CTepHMH /I.E (1995), OCHOBU raaoaoiifli/inaMi/iKyi,M3A MAM, MocKBa ... TRONG DONG DUCtt AM 1.1 He true toa d6 1.2 Canh eiia cu bay, cac tham so hinh hoc 1.3 Cac dac tinh dong eiia canh cu bay 12 1.4 T6ng quan cac phuofng phap xac dinh dac tinh dong cua canh cu bay. .. cua cu bay noi rieng Cac luc tijr dong tac dung len b^ mat cua eae ph^n tijf cu bay nhu: canh, duoi, than khong nhihig ehi phu thuoc vao che bay dac trung bcri cac tham so nhu: van t6e, cao bay. .. xac dinh vi tri eiia cu bay so vcri dong ma eon phu thuoc vao hinh dang ben ngoai, kich thude cua timg phan tir cung nhu sir phoi tri chinh so e^u cu bay Canh cua eu bay bao gom canh nang va