{1' KHOA HOC - CONG NGHE .
Phan mem xay dyng dac tinh vo tau, chan vjt trong dieu kien khai thac binh thaong
va tai hang thay ddi
• PGS.TS. DO DlJC L l / U ; PGS. TSKH. NGUYEN V A N Q U Y ^ ' T - TrUdng Dai hoc Hdng hdi Viet Nam
TOW T A T : Thuc te trong kiiai thac tau, d cac dieu kien khai thac binh thuang (KTBT) thl viec thay doi t i l hang khi tau van chuyen dSn den thay dot mon nudc lam cho lye can v6 tau thay doi Trong tinh toan, thiet ke v6 tau va lya chgn chan v\f hien nay thudng thyc hien cho che do toan tai hang, Trong thu nghiem duong dai tien hanh xay dyng dac tinh than tau thong qua thong so vin toe tau va vong quay chan vit va cung thuong dien ra 6 mgt che dd t l i hang (vi du tau chay ballast hoac co chd hsng vol muc dg tai nho). Tli hang chuyen chd duoc danh gia theo chi so tai hang Cargo - Load Index, CLi). Chi so nay thuong co mdi quan he vol man nuoc (chieu chim) trung binh cua tau Bai bao trinh bay ve co sd toan hoc va thuat toan cung nhu ket q u i phan mem tu dong xac dinh cac d?c tinh cua v6 tau va chan v|t trong cac dieu kien KTBT va CO CLI thay dot, tren co so ly thuyet tau, ket hop v6i cdng nghe lap trinh tren LabView (National Instruments, Hoa Ky) c6 ban quyen, Tnen khai ap dung cho tau bien chd hang tong hop 3 4 0 0 0 DV/T da dong tai Nha may Oong tau Pha Rung TL/ KHOA: Dac tinh vd tau va chan vit theo t l i hang, phan mem d§c tinh vd tau va chan vit.
ABSTRACT: In normal operating conditions of the ship, the changing ship cargo load (related with the ship draft and monitored by Cargo Load Index, CLI) influences on ship hull resistance and propeller characteristics Nowaday, the hull resistance is designed with only the normal CLI in sea trial, ship performance curves which depend on ship velocity and propeller revolution are also drawn with only one ship draft regime (example ship with ballast or ship with small draft) The CLI Is related with the ship average draft, T(m).
This article presents mathematical models, algorithms and software to calculate ship hull resistances and propeller characteristics in the normal working sea-conditions and with vanable CLI, which related with variable T(m) The
latical models are used according to the jory, and the software was programmed in (Nl, USA) There are applied for the MV )0 DWT. that built in Pha Rung shipyard
KEYWORDS: Ship Hull and Propeller characteristics vis Draft, VI for Ship Hull and Propeller characteristcs.
I.OATVANOE
Trong thiet ke tau daa ra bang tinh luc ein toan bo than tau eijng nha cac thdng sd dae trUng eho chan vjt d dieu kien KTBT va ehe dd toan t l i hang ehuyen chd (Full CLI). Luc cIn vd tau trong thiet ke dUOc xac dinh bang cle edng thdc gan dung, dUa ra t d ly thuyet tau. Cdng thde truyen thdng, chung nhat tinh cho cae thanh phan luc can vd tau khi tau boi tren nadc deu phy thudc vao ti trpng eua nude bien p (kg/m^), van tdc tau V(hli ly/h;
knots); dien tieh mat udt S (m^), kich thUde va hinh dang tau va eae he sd lye can d i e trUng [1,2,3,4]. Trong qua trinh khai thie tau vdl gia thiet eho trude: Bleu kien hang h l i eu the (song yen, bien lang, dd sau khdng ban ehe, vdng quay va cdng suat ddng co da biet...) thi van toe tau se phy thude vao che dd tai hang khai thae, taong dng vdi mdn nude trung binh T(m).
Thdng sd chi bao mdn nadc mui (T^) va l l i (TJ daoc thay bang ehi b l o mdn nude trung binh T = 0.5(Tp+TJ va Tp de dua vao eho cac edng thde tinh lae ein vd tau. 6 cung mdt ehe dp T(m), cd the xay ra cac mdn nUdc mui (tau) khae nhau, dan den lye can vd tau thay doi. Nha vay, doi vdi bai toan tinh lUc can vd tau theo chieu ehim ehung ta gia thiet dau vao chieu chim trung binh T(m) va Tp da biet, cac cdng thdc tfnh luc can eua vd tau d che do thiet ke (T^, T^) duac trien khai theo eo sd t o l n hpe truyen thong, sau dd tinh iye can toan phan cua vd tau d che do tai hang hien hanh T_ (m), khic vdt tai hang thiet keT^ (m) bang he so hieu ehinh k_ dUOc dUa ra theo hudng dan trong tat lieu chuyen nganh [2].
Trong thuc te thiet ke tau, vdi eo sd ly thuyet de dung eho tinh t o l n cac thanh phan lUc can tau kha phdc tap va sd luong cdng thdc toan hoe rat nhieu, vdi cac he sd phdc tap, hen quan mat thiet vdi nhau va phy thudc vao elc thdng sd kich thudc, hinh d i n g than tau, van toe tau (dau vao detinh, cd nhieu hesdean tra bang)... Viee tinh sde can tau va t d do xay dUng elc dac tinh cua vd tau, chan vit chi ed the thye hien tren may tinh. Hien nay, cdng viec tinh sdc ean tau khdng gap nhieu kho khan khi cac kysd thiet ke sd dung cac b i n g tinh Excel, mac du edng viec tfnh t o l n ed the mat nhieu thdi gian vi van mang nang
KHOA H O C - C 6 N G NGHE
So 04/2019
tinh thu edng. Ngoai ra, de x i y dUng elc dac tinh khai thac cua vd tau va ehan vjt (V(n ), \it\^) - cac dae tfnh van tdc tau, cdng suat tieu thu eua chan vjt theo d l i vdng quay khai thac chan vit) se phdc tap va khd khan hon eho kysu thiet ketau, dae biet lai md rong pham vi tinh t o l n cho bai t o l n tai hang thay doi.
Td nhu cau thye te trong tfnh t o l n , xay dyng cac dac tinh vo tau, chan vit cho khai thic he ddng lUe chinh vd tau - ehan vjt - m i y ehinh diesel tau bien, cae tac gia xay dyng phan mem t u ddng tinh lye can cua vd tau, cae thdng sd co ban cua ehan vit va xay dung hai dac tinh tong hop cua vo tau, ehan vjt tren he true tdng hop N (kW) -n (rpm) -V(knot). Co sd cdng nghe tien tien daoc sd dyng trong lap trinh la sa tich hop gida LabVievi/ va I\/lathSeript Toolkit (cung cua Nl), d dd lap trinh trong MathSeript dUOe phat trien va ehuyen tuong thich t d lap trinh m.file eua MatLab.
Phan vf dy minh hoa duoc ap dyng cho tau MVHR.34000 DWT da ddng tai Nha miy Odng tau Pha Rdng (Hai Phdng), trien khai lap trinh tren LabView va MathSeript.
2. QUY TRiNH VA CO Sd T O A N HOC X A Y DLTNG DAC TiNH VO T A U VA CH A N VjT
2.1. Quy trinh xay dUng cac dac tinh vo tau va chan vjt
Muc dich: Xay dyng eae dac tinh vd tau: RT-T,{n ), V[n ) dd la eae d i e tinh lUc can toan tau tat mdn nude T_,(m) va van toe tau (knot) theo sU thay doi vdng quay chan vit n (rpm), hoac theo vdng quay chan vit tuang ddi 'ri^=n^ln^^,, ky hieu 'nor'- chi dtnh mdc, Xay dyng cac dae tfnh chan vit tau d ehe dp taong dng vdi dac tfnh vd tau: He sd lUc day K^(n ), he so md-men \{n^, hieu suat ehan vjt ri (n )va dac tinh ehan vit Np(np). Quy trinh (thuat toan) gom cle bUde sau duac giai thich cung vdi eau true lenh trong MatLab:
BUdc 1. Nhap dau vao eho xay dung dae tinh:Tl'tca cac thdng sd hinh hoc, kich thUdc, dieu kien mdi tradng (nhiet do, ti trong cua nude bien), mdn nadc thiet ke Tj(m), mdn nude tat thdi diem tinh T_(m) va Tp(m),
Tao vector ban dau, vi dy: yn^= zeros(1 ,n); W = Vn^;
VK.|.=Vn ;VKQ^Vn ;Vn, - V n ; VN^ - Vn^ la cac vector ed n phan t d bang 0.
% Nhdp tdt cd cdc thdng so hinh hpc, thuy tinh... edn thiet cua chdn vit vd vd tdu d chi'dp
% Thii't ke, vi du cdc thdng sd ehieu ddi dUdng nudc L;
chieu rdng B; mdn nude trung binh
%Tj mdn nudc mui Tp the tich nUdc chiem chd Wd;
dien tich mat Udt S...
Vmin ^ 7; Vmax ^ 9.5; dT - 0.1; % Nhdp van toe tdu cdn tinh. vidu Vmax = 15; Vmin = 8;[knot];
V-Vmtn: 0.5: Vmax; n = max(size(V));%Xdci3(n/7 vector l/I
%Tgo vector ban ddu, ed kieh thudc (l,n):
W - V ; V n =V;VK, = V;VKg-V;Vn^ = V;VN - V ; Bu6c 2. Cho V = V^ = V, + (k-1). AV^AV = (V^^^_ "V^,J/n;
k=1,2,...,n vdi n t y c h o n ,
Cho van toe tau V(knot) cac gta tri t d V^^^ - V^, V^,..., V ^ V .
Lap trinh trong MatLab, cau lenh for... end se ehda caclenh taibUdeS, 4.
fork=l:n Vk^V(k);
Budc 3. Tfnh lUe can toan tau.
fiL/'dc3.7.Tfnh lye can toan tau R^^^, (kN) eua than tau tai mdn nudc thiet keT^;
% Chuong trinh con viet trong m.hle tinh ldc cdn todn bp ResistaneeJTd.m
Resistance_Td; % Goi ResistaneeJTd.m va tinh t o l n . File dupc viet vd lUu trd neng
St/dc 12.Tinh sde can R.|.^^,(kN) cua than tau tai mdn nadcT^qua hesd hteu chinh L
% Chuang trinh con viet trong m.hle tinh lUe cdn todn bp Resistance_Tx.m
Resistanee_Tx; % Gpi ResistaneeJTd.m va tinh toan.
File dupe viet va luu trd rieng
Budc 4. Tinh eae thdng sd cua chan vit (tUOng Ung vdt ehe dd van tdc V|_.
Sau khi tinh daoc lye ein eua than tau, ta xae djnh van toe ehan vjt n , tiep sau la cac he sd lye day, he so md-men, hieu suat ed ich cua ehan vjt va edng sul't chan vjt tieu thu.
% Chuang trinh con viet trong m.file tinh cdc thong so chdn vit PropFeatures.m
PropFeatures.m; % Goi PropFeatures.m va tinh t o l n . File duoc viet va lUu trd neng
VKT(k) - KT;VKQ(k} - KQ;Vnip(k) - nip;VNp(k) - Np;
%Gdn cdc gid tri eua ede vector ddu ra end
Bade 5. Md hinh hda (bieu dien bang md hinh toan) hai dac tinh eua vd tau, chin vit: N (n ) va V(n ) theo phuong phap giai tich hoi quy.Ta thu duoe md hinh dudi dang da thdc bae hai va da thdc bae nhat (tuyen tinh).
Md hinh hda dUOc thyc hien bdi ehuong trinh eon tfnh cac he so cua da thde md hinh va kiem tra dp tin cay eua md hinh thu dUOc theo tieu chuan thdng ke Fisher [5], viet trong m.file.
% Regressive_bae2_Np_np.m
Regressive_bae2_Np_np; % Got file va tinh md hinh, ve do thj ket q u i Np - aO-t-al *np+a2*npA2
% Regressive_bael_V_np.m
Regressive_bae1_V_np; % Gpi file va tinh md hinh, ve do thj ket qua V - bO-fbl *np
% LUu ket qud tinh vdo hie luu trd
save HullPropFeature_TxxxTxxxTF Vnp W VKT VKQ VnipVNpabFtaFtb
%Txxx Id gid trj mdn nUde Tx, vi du T895 eh! mdn nudc Tx = 8.95 m
%o-fc30o7(727-/dvecforcle hesd eua mdhinh bac 2, dp tin cay Fta - [% dp tin cly, r\^,nj
%b = [b0bl] -Id vector cdc hi sdcua md hinh bde I, do tin edy Ftb = [% do tin cay n ,,nj
BUdc 6. Ket qua dau ra can dUa ra dUdi dang bang hoae do thj cle dae tinh neu tren cho vd tau va ehan vjt, dac biet la hai dac tinh khai thac N (n }, V(n ),
2.2. Casdtoan hoc
2.2.1. LUC cdn thdn tdu d chi' do mdn nude thiet ke Tim) [1,3,41.
89
KHOA HOC-CdNG NGHE.
Cac eong thde toan hoc duoc sCt dung t d kien thde CO b i n eua ly thuyet tau (tUc can vd tau, chan vjt tau thuy) eung nhU cle cdng thde thuc nghiem duoc bd sung t d eae edng bd cua cac nha khoa hoc trong nganh da ddde p h i n tich trong bai bao [IJ.Gedam bao cho viec lap trinh thuan tien trong tdng edng thdc toan can the hien rd dau vao, dau ra cung elc dOn vi eda eae dai lUOng tham gia vao edng thUc tinh.
Luc can vd tau dupc tinh theo cac lUc can thanh phan, Viet bdt cdng thde
R,,^=R^{] + k^) + R,, + ff,„, + Rg + R,, + R^ + R^^ (1) Trong do: R^ - LUe can ma sat; k, - He sd tinh den sdc can hinh dang; R^pp - Lue cIn phan nhd; R^ - Lye can sdng;
Rg (Bulb) Lye can do anh hudng cua mui q u i le; R,,,, - Lye can bd sung do mpt phan dudi transom ngap dUdi nUdc;
R^ - Lye cIn dp nham; R^ - Lye can khdng khi.
Cac lye cIn thanh phan dupc tinh theo cac cdng thdc dupc ehi ra trong [1,2,3,4].
2.2.2. Lueedn thdn tdu d che dp mdn nude thue teTJm) [2]
Luc can cua tau khi cd sy thay doi chieu chim dupe d i n h g i l theo edng thde sau [2]:
^TT.^K^TT^ (2) k^=\-Y{h^^-\)^hj,,C„WXJ,),hr,^TJT, (3)
d dd, f|(.) - Ham sd tUdng minh theo cac bien can nhap vao ddOc de trong (); C^- He sd beo the tich; L(m) - Chieu dai tau. Cle dat luong dau vao deu dUOc xlc dinh.
2.2.3. Xdc dinh vong quay chdn vit n^(rpm) Lye can toan tau xac djnh theo edng thde (2) tai mdt ehe dp V(k) dUoc dung de xac dinh cac thdng so cua chan vit. Dau tien xlc dtnh he sd ddng theo Wt va he sd lUc hut t eua dong theo qua cle edng thdc tudng minh khi nhap cle gia trj cua bien dau vao cho cle edng thde taong dng [1,2,3]:
'*',=f'(Cfl>C„,C^.C,„CMB,Dp,L,L„,V,T,) (4) Trong edng thde (4) ngoai cac he sd ke trong (2), cae he so edn lat eung hoan toan dUOc xlc dtnh theo sd lieu dau vao cho qua trinh tinh toan: C„- He sd beo sUdn gida, C - He sd beo doe ehung than tau (C = C/C J , C ,
= 1.45Cp-0.315-0.0225L^g; L^^ - Khoang each gida tam noi vdi matsudn gida;T^-Mdn made dudi tau,m: T^-2T-Tp.
/ = f3(C,,,B,D^,UL^,„,V,T) (5) He sd lye day K^ va K^ dape xae dinh theo cac cdng
thUe thyc nghiem, phu thudc vao bien J =V/{n D ). Nha vay, dau tien ta phai xac dinh vdng quay chin vit n , sau do mdi xae dinh elc g i l tn chfnh xlc eua K^ K .
Viec xac dinh chinh xac vdng quay chan vjt n doi vdi tau duoc thiet ke, tai che dp vdng quay V thac hien theo eosd t o l n hoc va cosd ddlieu daoe daa ratal [1,2,4].
Gil thiet eho n^ g i l tri nao dd n , ta xac dinh so Re va
I
lech AR^- R^ -2E9. Xac djnh cac he so hieu chinh AK^kKjtheoAR tUcac edng thdc sau day:
I
^(Re = 2.10') = £ c , ( 7 ) ^ - { / ' / Z ) ) ' " ( 4 / ^ r " ( z ) ^ - ;\e(Rs = 2.lO') = f^C„{jf'(P/Dr'{A,IA,y'{zY' a£;A/:^=X/',e,
(6)
(7)
Kg(Re) = ^ g ( R e -2.10')-!-A/Cg{Re) '^' Cac he so trong edng thdc (6-8) deu dUOc dUa ra dudi dang b i n g [2]. Nhuvay, ta hoan toan xac ^ n h duoe hai he so phdc tap nay khi da biet V va gia djnh chon np.
Xuat phat t d quan he K^ = T/(pnp'Dp'') va =V/(npDp), ta ed:
VD^,4ilT=Jl4ic, (9) Dat: Kp^=VD .sqrt(p/T), cd gta tri khdng doi theo n^.
Ta tinh ngUoc lai gia trj n theo K^ vda tinh trong cdng thde (8).
Datn^-60*V/J/Dp.
Xae dinh gia trj vong quay cua chan vit vdi dp chinh xac deIn = n|-n = 0.5 (rpm).
% Thudt todn tudpngxdc djnh vdng quay n duac th^
hien dadi day:
KDT^V*Dp*sqrt(ro/Tx); % Tinh gid tn hdng so dvi trdi
%KDT = Vp*Dp*sqrt(1.025/r);
% Gdn gid tri n ban dau, cd the eho gia tri vdng quay chdn vit d che dp dinh mdc.
n = 129; % vidu npnor = 129;
deIn - 10; % Gin sai sd ban dau Idn while deIn > 0.5
% Khi delta > 0.5 thye hien maeh lap de tinh np
% Tinh KTtheo Vvdn vda gdn
% Tinh gid tri hdm dvephdi
% KTS=KT+CKT; % Tinh gid trlKT J=KDT*sqrt(KTS); m=60*Vp/J/Dp;
deln1-n1-n;deln=abs(deln1);
nf=n, n=n+0.3*deln1;
end
np=nf; % Gdn Iqi gid trinp vda tinh 2.2.4. Cdc thdng so ky thuat cabdn eiJa chdn vit Sau khi tinh chinh xae vdng quay cua chin vjt tai ehe dp V(k), ehung ta thuc hien eae bade tuan t y de tinh elc he sd KT, KQ, hieu suat ed ich cua chin vit nip va cong suat tieu thy cua chan vit. Cac cdng thdc toan d ^ tinh cle he so neu tren dupe de cap trong cae tai iteu [2,3].
Sau khi tinh xong eae thdng so cCia chan vit vdi t i t ea n gia tri cilia van tdc dat, ehung ta thu dUOc cac vector so lieu tfnh cac dai lapng: Van tdc tau W , vdng quay chan vit Vnp, luc cIn tau tai ehieu chim thiet ke va chieu ehim hien tai Tx (dat ra bat ky) VRTd, VRTx, he sd lUc day VKT, he so md-men VKQ, hieu suat cd ich cua chan vjt Vnip, cong suat tieu thu eua chan vit VNp. Moi vector cd n phan td, taong dng vdi che dp vdng quay khai thac cda chan vjt.
De xay dUng dat tinh tong hop N (kW) -n (rpm) -V(knot) cho tau, chdng ta cd the trye tiep sd dytig cle vector ket q u i thu daoc ke tren. Tuy nhien, de thuan tien xae dinh eae g i l tri cua cac thdng sd Np(kW) va V(knot) trong khai thac vdi van toe quay dupc chon la thdng so dieu khien (dau vao), chung ta xiy dyng hai md hinh t o l n hot quy bieu thi moi quan he gida cac vector cdng suat chan vjt va vdng quay (dudi dang da thdc bac 2) va van tde tau - vdng quay ehan vit (dUdi dang da thdc bac nh^t).
Phaong p h i p x i y dUng md hinh hoi quy t d xd ly so lieu
KHOA H p c - C O N G NGHE.
56 04/2019
thong ke tr^n co sd phuong p h i p binh phaong nhd nhat cae sai so va cd kiem tra dp tin cay cua md hinh theo tieu chuan Fisher.
3. PH A N M i M XAY Dl/NG C AC OAC TfNH v 6 T A U , CHANVIT
Phan mem dupe lap trinh tren LabView, thye hien tren giao dien ehinh (Front Panel, FP) eung nhu xay dung code tat Block Diagram (BD). Lap trinh tren LabView mang tinh true quan eao, dudi dang do hoa va rat tien ich, nhanh ehdng va tiet kiem nhieu thdi gian. Lap trinh tren FP cho hien thj va dieu khien dupe trien khai nhd thu vien mau cd sin trong LabView, edn lap trinh code tren BD cd the sddyng rat nhieu cdng eu tien ich cd sin trong LabView, ben canh do cd the lap trinh MathSeript tuong tunhulaptrinh m.file trong MatLab.
Odi taong I p dung la tau MV.HR.34000 DWT da dong tai Nha may Ddng tau Pha RUng, cac thdng sd ca ban cua vo tau, ehan vjt dupc nha may eung cap, Tren ea sd b i n ve thiet ke 2-D than tau, chung tdi da tinh tat ea elc thdng so thuy tinh can thiet de nhap vao eho qua trinh tfnh lye cIn v l eie thdng sd eua ehan vit.
Dau vao elc tac gia chi bd tri mpt bien dieu khien la nhap mdn nude T(m), Tp(m), dau ra la eae gia tri tUPng dng eua thdng sd dupe tinh. Tren giao dien chinh (FP) rat true quan va don gian eho ngUdi khat thae. Phan lap trinh Code trong Block Diagram duoc xay dyng tren eo sd ket hop m.file trong MatLab va MathSeript trong LabView, rat tien feh va nhanh ehdng eho nhdng ngudi da cd kinh nghiem trong lap trinh MatLab dudi dang m.file,
Ket qua lap trinh giao dien cht'nh de hien thj eae dac tinh co ban cua vd tau va chan vjt tau MV.HR.34000 DWT dUi?c the hien dudi dang hinh tdng hpp Np(kW) - n ^ -V[knot} duac the hien tren Hinh 3.2 va 3,3, tuong Ung vdi mdn nudc T = 9.75 m va T = 9,00 m. Tren Hinh 3.4 vd 3.5 - bang ket q u i cic die tinh cua vd tau, chan vit d hai mdc mdn nude taong Ung. Tren Hinh 3.1 - giao dien chung gidi thieu ve tau dUOc ap dyng nghien cUu va cle ehe dd dieu khien, hien thi tren man hinh tinh.
Hinh 3.1: Giao diin chinh gidi thieu vephin mem Tren giao dien chinh ed nut dieu ehinh mdn nudc bSng eleh nhip vao g i l trj mdn nudc thuc te can tfnh toan, xay dung dae tinh. Sau khi nhap xong g i l trj T{m), vf du T=9.75, ta nhan nut STOP (Run/ Stop).
Tren phan man hinh hien thi ed cle ehe dp hien thi
ket qua qua viee nhan chudt vao "ed" tUOng dng, vi du
"General lnform"nhatren Hinh 1.
Tat ehe dpT ^ 9.75(m), dac tinh eua vd tau - ehan vit (VT-CV) tau MV.HR.34000DWT d che dp KTBT dUOc the hien tren Hinh 3.2 va tUong Ung vdi b i n g ket qua, the hien tren Hinh 3.4. Cdn tai che dp T = 9.00 (m), cac dac tinh tuong dng dUOc the hien tren Hinh 3.3 vd 3.5.
Hinh 3.3: Die dnh CV-VT&chedd KTBT, T=9.00m Tren Hinh 3.2 vd 3.3, PPC(n) la dae tinh edng suat ehan vit, kW, tinh d eae ehe dd vdng quay n(rpm) cua ehan vit, dong thdt eung la vdng quay cua dpng co diesel m i y ehinh, cdn V(n) - d i e tfnh van tde tau theo vdng quay ehan vit. Ket q u i the hien trUc quan cac dac tinh tong hpp, thuan tien eho sT quan may tau bten khi khai thae he dpng lac chinh tau bien.
Hmh 3.4: Bang ket qui cic dac tinh VT-CV tai T=9.75m
91
KHOA HOC - CONG NGHE _
Cac cdng thde toan hoe dupc sd dung t d kien thde CO ban cua ly thuyet tau (luc can vd tau, chan vit tau thuy) eung nhu cac edng thde thuc nghiem daoc bo sung t d cae edng bd cua cle nha khoa hoc trong nganh da dUOe phan tich trong bai bao [1]. De dam bao cho viec lap trinh thuan tien trong tdng edng thde toan can the hien rd dau vao, dau ra eung cle don vi eua eae dai lUOng tham gia vao cdng thdc tinh.
Lye can vo tau duoc tinh theo cac luc can thanh phan, viet bdi edng thdc
fl^^ -flp(l + *:,) + K„ +lt,,^r + RB->-lij^ + R^ + R.^ (1) Trong do: R^ - Lye can ma sat; k, - He so tinh den sdc can hinh d i n g ; R^^^ - Lye can phan nhd; R^^ - Lye can sdng;
Rg (Bulb) Luc can do anh hudng cua mdi qua le; R^^ - Lye can bo sung do mdt phan dudi transom ngap dUdl nUde;
R^ - Lye can dp nham; R^^ - Lye can khdng khi.
Cac lye can thanh phan daoc tinh theo cac edng thde dupe ehi ra trong [1,2.3,4],
2.2.2. Lue cdn thdn tdu d che do mdn nUde thue teTJm) [2]
LUe can eua tau khi ed sUthay doi ehieu chim dape danh gia theo edng thde sau [2]:
^ f T i - M r T - , / (2) I', = I + (A^, - l)f,(/v,.Cs, V,L,Tj);/ir, = TJT^ (3)
6 dd, f,(.) - Ham sd tUdng minh theo cle bien can nhap vao dupe de trong (); C^- He so beo the tfeh; L(m) - Chieu dat tau. Cae dai lUpng dau vao deu dupe xie dtnh.
2.2.3. Xdc dinh vdng quay chdn vit n (rpm) Luc can toan tau xac djnh theo edng thde (2) tai mdt che dp V(k) dapc dung de xac dinh cac thdng sd cua chan vit. Dau tien xlc dtnh he sd ddng theo Wt va he so lye hut t cua dong theo qua eae edng thde tUdng minh khi nhap cac gia trj cua bien dau vao cho cac edng thdc tuong dng [1,2,3]:
H^, =fj(C^,C„,Cp,C^,,C,.,B.I3,,.L,L^a,V,TJ (4) Trong edng thde (4) ngoat cle he sd ke trong (2), cac he so cdn lai cung hoan toan dupe xlc djnh theo so lieu dau vao cho qua trinh tinh toan: C^- He so beo sUdn gida, C - He sd beo dpc ehung than tau (C - C^/CJ, C ,
^ 1.45C -0.315-0.0225^.^; L^.^ - Khoang eleh gida tam noi vdi mat sudn gida;T^ - IWdn made dudi tau,m: T^^ - 2T-Tp
f = f,(C„,B.D^,L,L;,,.V.T) (5) He sd lye day K^ va K^ dUpc xae dinh theo cac edng
thdc thUe nghiem, phu thudc vao bten J = V/(n D ). NhU vly, dau tien ta phat xac dtnh vdng quay ehan vit n , sau dd mdi xlc djnh eae gia trj chinh xae eua K^, K^.
Viee xac djnh chinh xac vdng quay ehan vjt n ddi vdi taudupethietke, tai che dp vdng quay V thuc hien theo CO sd toan hoc va cosd ddlieu dupe dua ratal [1,2,4].
Gil thiet cho n^ g i l tn nao dd n , ta xac dinh sd Re va dp Ieeh AR^= R^ -2E9. Xac djnh cle he sd hieu ehinh AK^
va AKQ theo AR^ tdeae edng thde sau day:
K,(Re = 2.10") = £C„{J)'' ( P / D)'-{A, I A,)"• (z)'-;
'-I (6) K^,(?.z = 2.\{i') = Y.C„Uf-(PI D)''(A,I AJ-izy-
^T ^ i",^.'^^ = S * ^ 2 , (7)
90
^ g ( R e ) = . ^ 2 ( R e = 2 . 1 0 ' ) + A / : g ( R e ) *^' Cac he sd trong edng thdc (6-8) deu dupe dua ra dudi dang bang [2]. NhU vay, ta hoan toan xlc d|nh duoc hai he so phdc tap nay khi da biet V va g i l djnh ehpn n^.
>Cuat p h i t t d quan he K^ = TApn^^D^'') va ='V/{np^), ta ed:
vD,,4iiT^ji4r, (9) Dat: Kp^ = VD^.sqrtip/T), ed gia trj khong doi theo n^.
Ta tfnh ngUOc lai gia trj n^ theo K^ vda tinh trong eong thde (8).
Datn,= 60*V/J/D^.
Xlc dinh gta trj vdng quay eua chan vjt vdi dp ehfnh xac deIn - n,-n = 0.5 (rpm).
% Thudt todn tuddng xdc dinh vdng quayn^ dupc the hien dudi day:
KDT = V*Dp*sqrt(ro/Tx); % Tinh gid tn hdng sodvetrdi
%KDT - Vp*Dp''sqrt( 1.025/T);
% Gdn gid trj n ban ddu, eo the cho gia tri vdng quay chdn vit dchedp dinh mde.
r\= M9;% vidu npnor = 129;
deln = 10;%Gansais6bandauldn while deIn > 0.5
% Khi delta > 0.5 thac hien mach lap de tinh np
% Tinh KT theo Vvdn vda gdn
% Tinh gid tri hdm d vi'phdi
% KTS^KT+CKT; % Tinh gid tri KT J-KDT*sqrt{KTS); n 1 -60*Vp/J/Dp;
delnl=n1-n;deln^abs(delnl);
nf-n;
n=n-H0.3*deln1;
end
np=nf; % Gdn lai gid tn np vda tinh 2.2.4. Cdc thong sd ky thudt ca bdn cua chdn vit Sau khi tinh ehinh xae vdng quay cua ehan vjt tai che dd V(k), chiing ta thuc hien cac bUde tuan ta de tinh cac he sd KT, KQ, hieu suat cd ich eua chan vjt nip va cdng suat tieu thu eua ehin vit. Cac cdng thde t o l n de tfnh cac he sd neu tren dupe de cap trong eae tai lieu [2,3].
Sau khi tinh xong eae thong sd eua ehan vjt vdi t i t ca n gia tn cua van tdc dat, chung ta thu duoc cle vector sd lieu tinh eae dai luong: Van tde tau W , vdng quay chin vjt Vnp, lye ein tau tai ehieu chim thiet keva chieu ehim hien taiTx (dat ra bat ky) VRTd, VRTx, he sd lye day VKT, he sd md-men VKQ. hieu suat cd ich eua chan vjt Vnip, cdng sul't tieu thu eua chan vjt VNp. Moi vector ed n phan tCf, tuong dng vdi che dp vdng quay khai thac cua chan vit.
De xay dung dat tinh tong hop N (kW) -n (rpm) -V(knot) cho tau, chung ta cd the trUc tiep sd dung elc vector ket q u i thu dupe ke tren.Tuy nhien, de thuan tien xac dinh cac gia tri eua cac thdng so Np(kW) va V(knot) trong khai thac vdi van tdc quay ddOc chpn la thong sd dieu khien (dau vao), ehdng ta xay dung hai md hinh toln hdi quy bieu thi mdi quan he gida elc vector edng suat chin vit va vdng quay (dudi dang da thdc bac 2) va vin tde tau - vdng quay chan vjt (dUdi dang da thdc bac nhSt).
Phuong phap xay dUng md hinh hdi quy t d xd ly so lieu
