Dtf BOAN TJNH NANG flIEU DONG TAU sir DUNG K - T MODEL

KHOA H Q C - C 6 N G NGHE

Dtf BOAN TJNH NANG flIEU ^{D O N G} TAU sir DUNG K - T MODEL

Tdm tdt: Md hinh toin hpc K- T dc nhit li m0t trong nhtfng md hinh ddn giin, hidu qui md ti chuyin d^ng cda con tiu. Sd dpng md hinh toin hpc K - T gidp ta d thi nghiin du kyhdnvSkhi ning chuyin dng da con tiu mi khdng dn phii Sin hinh thd tiu nhliu lin ngoii thtfc dia hdc thtf vdi md hinh. Bii viit dy gidi thiiu phtfdng pdp phin tfoh dc hd si cda md hinh tdn hpc K-T ttf mpt si kit qui thCf tiu.

Abs^act: The first order K-T modi is one of simple ad effective mdels which desdd Ute movement of ship. By using K-T model, we can study more detail adut ship's movement mthout carrying out ship tests or mdel tests, in this paper, the methd to analyze the coefficients of K-T mdel from the results of sea trial is presentd.

I.GIdithlfiu

Md hinh toin hpe K - T dUpc Nomoto gidi thifiu d i tCr l i u . Mfi hinh K - T bfie nhdt l i mfit trong nhQng mfi hinh ddn giin mfi t i khi ning thay ddi hudng di ciia con tiu dudi tic dgng ciia gdc bfi binh lii. Tuy nhifin, vl$c sijr dgng mfi hinh K - T model phgc vg nghidn ci3u khoa hpc hifin nay chij ydu dpa vio cic mfi hinh sdn cd. Ngudn dO lifiu niy cOng khfing ddi dio. Mit khic, m&i con tiu Igi cd mfit tfnh ning didu dfing khic nhau. Chinh vl thd m i eh? sit dgng mfit sd mfi hinh tiu hgn chd khd cd thd dinh g i i ddy dO khi ning didu dfing ciia tdt c i cic logi tiu v i cung khfing thl dp doin tinh ning difiu dfing cDa mfit eon tiu cg thd.

Do dd, khdng cung cdp dupe nhidu cic thdng tin hdu fch cho ngudi difiu khidn phUdng tifin cung nhu cic nhi nghifin cdu khic.

Vific nghifin cdu phin tfch mfi hinh toin hpc K - T ciia cic tiu tU mfit sd kdt qui thit t i u trfin trudng thijf sfi khde phgc dUpc cic mgt hgn chd nfiu trfin. Chi tidt vd qui trinh phin tich eung nhu t i c dgng ciia vific nghifin eUu se dUpc trinh biy d cic phdn sau.

2. Mfi hinh t o i n hpc md t i chuydn dfing cua con t i u

Mfit con tiu chuydn dfing dupe trong nudc l i do tic dfing eiia binh l i i , chin vjt v i cie thinh phdn lpc c i n ciia nude tie dfing Ifin thin tau.

Binh l i i giiip tiu giO dn djnh cung nhu thay ddi hudng di. Ngoii ra, nd cung tgo ra lpc cin khi phUdng ciia lpc bd l i i khfing trUng vdi phUdng chuydn dfing cCia t i u . Dd mfi t i inh hudng ciia binh l i i ddi vdi sp thay ddi hUdng dl ciia con t i u ta cd ttid sii dgng mfi hinh K - T bfie nhdt:

T.i|/ + v = K.6 0)

Do lpc bd l i i tuy thufie v i o tde dfi ddng nude ddn

mfit binh l i i . Ta se ed cic hfi sd khic nhau d cic tde dfi khic nhau. Dd sit dgng cho mpi tde dfi t i u , ngudi

TS. PHAM VAN T H U A N ^ Trudng Dpi hpc Hing hil ta sis dgng cic he sd khfing thU nguyfin ciia K v i T:

dd la K' v i T'.

K = K - ^ (2^

T = T - (3)

Anh hudng cda chin vit v i lpc tie dfing ciia nuda lam thay ddi tde dfi t i u theo phUdng trinh sau: a

v-i-a„.v^+a„j^ =a^ji^+a„^.n.v (4)

Trong dd:

5: Gdc b i l i i , i|f: Hudng di eiia t i u , v: Tde dfi tiu,

Lpp : Chifiu d i i giQa hai dUdng thiiy trpc cCiatiu, K, T, K', T: Cic hfi sd thU nguyfin v i khfing thil nguyfin cQa mfi hinh K-T.

v: Tde dfi tiu, n: Vfing quay cOa chin vit, r: Tde dd quay trd,

aw, a^, ann, anv: Cic hfi sd md t i inh hudng c&a vdng quay chin vjt, tde dfi quay t^ eOa tiu v i tde dfy tiu.

ChUng ta nhfin thdy i i cic hfi sd K', T, a»v, an, am, anv la cic hfi sd die trUng cho chuydn ddng cCia tiit\q eon t i u . Bi dinh g i i tfnh ning dieu dfing ciia con tiu, cin thidt phii xic djnh eic h$ sd trfin v i sau 66 stf dgng chUng dd t i i hifin c i c chuydn ddng cOa con tiu. Ti:f dd, ta c6 the danh g i i tfnh ning dilu d^ng ciia con t i u . Vific dp doin cic hfi sd kd trfin 6\i(}c trinh biy d phdn sau.

3. Dp doin cac h$ sd mo t i chuydn dfing cda con t i u

Vific dp doin cic hfi sd mfi t i chuydn ddng offa con t i u theo phuong trinh (1) v i (4) ed thd dui^c tidn hinh dpa trfin mfit sd kdt q u i thil t i u trfin trUdng thil.

Cg thd nhu sau:

3.1. Xic dinh KviT

Hinh 1: Tinh tdn hisSK.T dtfa trin kit qd thU 2lgzag

KHOA CiQC - C S N S N @ H | Tap Chi GTVT 4/2012 1 1

Hi s6 K', r duoc x4c djnh di;a trSn kft q u i ttiijr zigzag ciia tdu nhu sau:

PfiUOng trlnfi (1) vl^t cfio chuyin dfing cOa t i u gIDa hai thdi dilm gSn nhau t. va ID, ta co:

'>,

T.(>i',g-¥,.,) + (V„,,-¥,,,) = K.j5.Jt+0,(t^-t.) ,5,

>.

Hudng mui tiiu tai eSe thdi dilm: t., t.'. V dUdc tinh nhu sau:

V, =K2.j[8„.dt + K.5,.t,

0

Vj/,, =K,.j5„.dt + K.8,.t,,

0

v.. =Ki.|8„.dt + K.8,.t,.

(6)

(7)

(8) TCI phUdng trinh (7), (8), (9) tim dUde cdc gid tri cOa K2; K.; KB.

Til phUdng trinh (5), n l u chon t. = t2; t.; ts vd tb = t.; U': t." tuong Dng vdi Ka: K4: Ke, ta tim dUde cdc gid trj cDa Ta, T4, Te.

T ! = T - ^ . ( V . - V 2 ) - K J J6..dt+6,.(t.-t2)

Vj-V.l_ \i J T, = T 4 T - (f.-V.)-Kj '|5.Jt+6,(t,-t,)'

Ti = - - ^ (V.-Vj-K. J5.it+5,(t,-t,:

Vi-V,

Gid tri K. T dUdc xde djnh nhu sau:

j^J±±k

(9)

(10)

(11)

(12) (13) L

Gii trj K' v i T dUpc xie djnh theo phUdng trinh (2), (3).

Ngoii ra, ta cung cd thd xac djnh g i i trj ciia K khi tiu quay trd dn djnh. TCf phuong trinh (1) khi gia tde quay trd bing khfing: v = K.5 • Khi bidt g i i trj ciia gdc bfi binh lit v i tde dd quay trd dn djnh trong thQ quay ta cd thd x i c djnh dUpc g i i trj cua K.

3.2 Xic dinh Bn, an, Bnn, anv

can cU v i o phUdng trinh (4) chung ta nhfin thdy tQng hfi sd dupc xic djnh khi cd thd logi trQ hoac bidt trUdc c i c hfi sd khic. Chiing ta cd thd phin tfch cie hd sd ciJa phUdng trinh (4) theo trinh tp nhu sau:

- TQ kdt q u i thQ ham tp do ta nhdn thdy cie thinh phdn do vdng tua chin vjt v i quay trd ddu khfing cd i n h hudng. PhUdng trinh (4) trd thinh:

v-(-a„.v^ =0

- TQ kdt q u i thQ tde dd. khi t i u chgy 6 tde dd dn

dinh. DhUdna trinh (4) trd thinh:

a „ . v ^ = a ^ j i ^ -i-a„^,Ji.v

Qua ket qui thQ tde dfi t i u ddi vdi eic chd dp may khae nhau ta thu dupc cac tde dd t i u khic nhau. TQ dd ta cd thd xac djnh dupe cae hfi sd app, a^y.

- TU kdt q u i thQ quay trd, tgi giai dogn t i u quay trd dn dinh. ohUdno trtnh (4) trd thanh:

a„.v^+a^j^ =a^.n^+a„^ji.v

Ta cd thd dp doin dupc a„ ttf ket qui quay trd dn djnh khi da bidt dupc eic thfing sd ay^ ^nn> ^nv-

Vdi kdt qui dp doin cOa tdt c i eic hd sd, chuydn dgng cQa con t i u dupe mfi phdng Igi dpa trfin hai phUdng trtnh (1) va (4). Cin cQ vio kdt qui mfi phdng Chung ta ed thd dinh g i i dUpc c i c tfnh ning didu dpng tau mfit cich chr tidt, cg thd hdn nhQng kdt qui cd dupc tQ thQ t i u trfin trudng thQ.

4. Kdt lufin

TQ mfi hinh K - T b i c nhdt, t i c g i i gidi thifiu hfi phUdng trtnh mfi t i chuydn dfing cQa tau co xem xfit ddn inh hudng ciia cic thinh phdn lpc tic dfing ddn tde dfi t i u cung nhU inh hUdng ciia tde dfi ddn hifiu q u i bd l i i . Trfin cd sd ciia mfi hinh toin hpc, b i i vidt gidi thifiu phUdng phip xic djnh cic hfi sd mfi t i c i c dac trung didu dfing cQa tiu. Ngoii vi$c xic djnh K v i T cd tham khio kdt qui nghifin cUu cQa cae t i i lifiu khie, phUdng phip xie eic hfi sd cdn Igi dUc^c t i c gii xiy dpng trfin cd sd t i n dgng cic kdt qui thQ t i u . Vific lam niy giiip ngudi sQ dgng d l ding x i c djnh eic hfi sd dd v i nd cd the tidn hinh vdi bdt ky t i u nao, trong bdt ky didu kifin t i i trgng nio. Do dd, khfing cdn phii tfi'n nhifiu thdi gian v i tidn bgc eho vific thQ tau. V i chOng ta ed thd ed dupe sd lifiu vdi nhidu didu kifin t i i trpng khic nhau ciia con t i u . Giiip chung ta co thd dinh g i i dupe khi ning difiu dfing cua eon t i u trong mgi didu ki^n t i i trpng.

Tuy dfi chfnh xic cQa mfi hinh K - T khfing bing dfi chfnh xie cCia mfi hinh MMG nhUng vific xiy dpng cd sd dQ lifiu mfi t i khi ning difiu dfing cua t i u de ding hdn. It tdn kim hdn. Vific Qng dgng phUdng phip niy cd thd gliip ta dp doin khi ning didu dfing cho mgi mgi con t i u . Vific lam niy tidt kifim dUpc thdi gian, chi phi va ed thd thu dupe ngufin ed sd dQ lifiu ddi dio phgc vg nghifin cQu khoa hgc. Ddng thdi, eic kdt qua mo phdng lai chuydn dfing cua con t i u cung cung cdp cho cie sy quan hing h i i cic thfing tin chi tidt hdn ve eie tinh ning dieu ddng t i u phgc vu cho din t i u an toin •

Tai lifiu tham khio

[1]. Phgm V i n Thuin, Doctoral thesis, 2009.

[2]. Pham Van Thuan, KOBAYASHI Hiroaki, "EvaiuaSon of container ship maneuvering characteristics from view point of ship handling abiiit/'; Journal of Japm Institute of Nav- igatk)n, Vol.118, p283-289. 2008.

[SJ.TTw f^eseamh Committee of Dynamic Periormance Manoeuvring and Control Section, "Prdidon of maneu- verabiHty of a ship". Bulletin of the Society of Naval Archi- tects ofJ^jan No. 668, Fdruary 1985 (Transla^ from J^ianese by Takako Bundgaard, ditd by M.S. Chislett for Dams/? Maritime Institute, 1986).