Tgp chi Khoa hgc - Cong nghe Thuy sdn So 3/2014 THONG BAO KHOA HOC NGHIEN CUtJ MO PHONG THUY DONG LUC HOC CHUYfiN DONG CUA TAU THUY TREN SONG DIEU HOA RESEARCHING OF HYDROD YNAMIC SIMULATION SHIP MOTION IN REGULAR WAVES Ngay nh^n bii 21/S/2014,Ngay phan bi^diong qua: 22/6/2013; Ngay duy^t dang: 13/8/2014 T O M TAT Bdi bdo trinh bdy kit qua nghien cuu mo phong thuy d^ng luc hoc chuyen dong cua tdu thtiy Iren song, bat ddu tir vi4c xay dymg mo hinh mgt tdu cha hdng cu the phdn mem Ihielkitdu Ihuy Auloship, sau chuyen sang AQWA, modun phdn tich thiiy dgng iifc hpc aia phdn mem ANSYS de Ihuc hi^n mo phong va phdn tich chuyen dong cua mo hinh tdu ndy tren song bdng phucmg phdp linh lodn dpng lyre hpc chdt long (Computational Fluid Dynamics - CFD) Ket qud mo phang thuy dpng lifc hpc se la ca sa de giai cdc bdi todn lien quan den chuyen dong tau tren song nhu tinh bien dao dong, linh sire cdn phdn tich anh hu&ng song, tdi trpng tren tdu den chuyen dpng Idu v v Tu khoa: mo phong thdy dpng l^ hpc, phdn mem AutoShip, AQWA -ANSYS RAOS ABSTRACT This paper presents the research results ofhydrodynamtc simulation ship motion in regular wavea Beginning from building the model of cargo ship by Auloship - ship design software to importing lo AQWA - Hydrodynamic module of ANSYS orders lo simulate and analyse ship motion in regular waves by Computational Fluid Dynamics - CFD This hydrodynamic simulation results will be basic to solve the problem concerning to ship motion in regular waves such as caculale Response Amplitude Operators (RAOS), ship resistance, effecting of regular waves, load to ship motion etc Keywords: hydrodynamic simulation, AutoShip software, AQWA-ANSYS, RAOS DAT V A N D £ Tinh toin dpng lyc hpc chit Idng (Computional Fluid Dynamics - CPDf l i mflt phuang phdp tinh mdi, dupc xdy dyng trdn ca sd kit hpp gida phuang phdp so vd cdng ngh$ md phong trdn mdy tinh d l gidi nhUng bdi todn lifin quan d i n chuyin dflng cua dong chit Idng ho0c ddng chat bao xung quanh v|t t h l b i t ky Nd hifin dang dupc irng dgng rdng rai nhilu tTnh vyc nhim to chdc thyc nghi#m trfin mdy tinh thay cho thyc nghipm md nhilu khi, viflc t l chirc thyc nghipm thgt cd t h l r i t t i n kdm hogc khdng t h l thye hi§n Vdi vai trd quan trpng nhu t h l nfin CFD dupc cdc nhd khoa hpc nhin nhdn nhu Id "phuang phdp thir ba' cting hai phuang phdp nghidn cuu truyin thdng Id nghidn ciru ly thuylt Hiuin vd thyc nghidm thuin tiiy, td chuc nghifin ciru vd phdt triln nhifng U'ng dgng ky thudt r i t nhilu ITnh vyc khoa hpc khic Trong nhung nam gan day, CFD dd dupc v#n dyng rflng rai md phdng ddng chit long chay xung quanh b l mgt than tdu, nham khdo sat cac hien tupng thtiy ddng lyc hpc xuat hlfln tdu ehuyen ddng tren sdng Vdi y nghTa do, bdi bao ndy trinh bdy kit qud eua chiing tot nghien cuu dng dyng phuang phdp CFD, bdng cdch sir dyng AQWA ANSYS - mdt mddun tinh todn thiiy dflng lyc hpc cOa bfl phin mlm Ansys d l thyc hifin vi#c md phflng vd tinh todn thuy dong lye hpe cho mflt tdu eg t h l (I PHLfONG P H A P V A NOI DUNG NGHIEN CU'U Ve mdt phuang phdp, song biln t y nhifin diing nghien cdu cac chuyin dflng cfl chu k^ cua tdu thiiy dupc xet nhu Id tap hpp eiia vo so sflng dilu hfla bifin dfl nhd, cd t i n s6 vd chu ky khde nhau, pha nglu nhien Phdn irng eua tdu vdi nhieu ' PGS TS TrSn Gia Thdi: Khoa Ky thu$l giao thflng - Tnrtrng Dgi hpc Nha Trang CFD Id diG vilt tit cua cym h> tiing Anh 'Computational Fluid Dynamics" da dugrc sd dyng phfi bien, 66 chung loi se sir dyng thudt ngir vi^t tit ndy su6t cdc n^ dung cua bdi bdo TRUONG DAI HOC NHA TRANG • 77 Tgp chi Khoa hgc - Cong nghe Thdy sdn SS 3/2014 sflng dilu hfla cb bifin dO, t i n s6 khde nhau, pha nglu nhifin, tdc d$ng ding thdi, dupe xdt nhu Id mpt qud trinh nglu nhifin, se Id t§p hpp cCia cdc phin trng rifing Id ctia tdu vdi tirng eon sdng Khi do, tinh todn thCiy dflng lyc hpc ctia tdu trfin sflng t i nhdm xie djnh phdn ung cua tdu tren sdng dilu hfla, thflng qua viflc xic djnh cic thflng s6 dao dflng eiia tdu vdi bifin dfl vd ehu ky phy thuflc bien dfl, t i n so sflng, eg t h l nhu cic yeu t l thuy tTnh (Hydrostate), thiiy dflng h(?c (Hydrodynamic), bidn dfl dao dflng ciJa tdu (Response Amplitude Operators - RAOs), phdn b6 ctia dp suit thtiy dflng lyc hpc (HydnDdynamie pressures) vd cdc ehuyen dflng eua tdu tren sflng (motions), cdc lyc cuang btrc (lyc Froude - Krylov) hfi s6 edn Cho d i n hifin nay, bdi toin thuy dpng lyc hpc tdu thtiy thudng dupc giat bang ky thudt CFD trng dyng cho ddng chit ldng chdy Xdy dyng mfl hinh tdu Autoship bao xung quanh thdn tdu thOy, kit hpp friyc nghi?m d l kilm djnh Igi mfl hinh tinh [3], Do dfl ht§n cung da cd nhilu phin mlm CFD nhu AQWA dting de phdn tich thiJy dflng lyc hpc tdu tiii)y Tuy nhifin, vln d l ddt d ddy l i vific xdy dyng md hinh thyc t l cua tdu tinh toin cde phin mlm nhu t h l g|p nhieu khd khdn vl hinh dang phuc tgp cua ^ d n tdu vd khd nang tilp nh|in chinh xdc mfl hinh tfnh [1] Trong nghifin cuu ndy, chung tfli gidi bdt toan dgt trfin ca sd sif dyng phin mem thilt k l tdu Autoship xdy dyng chinh xdc mfl hinh tdu vd chuyin nd sang mfli tnfdng CFD mddun phdn ticli thuy dflng lye hpe AQWA cua ANSYS d l thyc ht§n cdc tfnh todn thtiy dflng lyc hpe theo trinh ty gidi bat todn CFD da bilt I^pt edeh ting qudt, cd t h l torn tat phuang phdp vd npi dung nghifin ciru bdng sa 36 nhu m d t i trfin htnh Chuyen mfl hinh tau sang tinh todn CFD trang AQWA ANSYS Tinh todn vd thilt lap cde Uiong si vdt ly ciJa mfl htnh CFD i Chia ludi vd thilt ldp cdc dilu kifin bifin Tinh todn vd phdn tich thuy dflng lyc hpc mfl hinh tdu dang xet m n h Sor qui trinh nghiSn cihi X i y dyng md hinh tdu p h i n mem thilt ke tdu Autoship Tiln hinh xdy dyng phan mlm thilt kl tau Autoship mfl hinh cOa mflt tau chd hang dgng hdng trfln, mui vd dufli cd dgng qui lfi, bo tri thfim mot chan v[t day ngang d mui vd cd cdc kich thudc chinh nhif sau: - Chilu ddi toin bp (pverati length): L = 24 m; - Chtlu rflng (breadth): B = m; - Chilu cao man (depth): H = m, - Bdn kinh hdng: r = m; III K^T QUA NGHIEN CU'U VA T H A O L U A N Glc tpa dfl dupc dgt tgi vt tri giao dilm g i ^ Qui trinh xdy dyng vd thilt lgp cdc thdng so thdn tdu vdi phia dudi song chinh (keel) eOa tau mfl hinh tdu ttnh todn AQWA thyc hipn theo {hinh 2) Trinh ty thye hipn bdi todn ndy dupc trinh trinh ty: bdy ey the t i l lifiu [3] ciJa ciing t i c gtd Trong pham vi ciia bdi bdo ndy, chiing tdi se trinh bdy cy t h l ky thu|t xdy dyng vd thilt lap cde thflng s6 cua mdt md htnh tdu eg the mdt trudng AQWA de tinh vd xuat k i t q u i tfnh thiiy dflng lyc hpc tdu Trong bit bio tiep theo, chung tdi sfi trinh b i y k i t q u i tinh doi vdi md hinh tdu da cfl so It^u thyc nghiflm d l cd the so sinh, dinh g i i k i t q u i tinh tir phan mem vdt s6 lipu thyc t l Hinh Mo hinh tiku h&ng khao sdt 78 • TRUONG OAI HQC NHA TRANG Hinh MS hinh tim h^ng dyng Autoship So 3/2014 Tgp chi Khoa hgc - Cdng nghe Thuy sdn Sau dyng xong md hinh, tiln hdnh tgo thdnh mpt nhdm chung cho todn t>fl cdc bfl phdn tdu da dyng, sau dd nhip chuflt v i o mgc View va chpn myc RenderQe td bdng todn bp md hinh t i u nhu md ta tren hinh Luu Igi mfl hinh tdu dudi dgng file ed dudi iges bang cich chpn myc File -> Export -^ IGES —* chpn noi luu vd ten file md hinh tdu, vf dg ship.igs —*• chpn Yes hop cau hdt: 'Split Objects at Comers?" - * nhgp hflp thogi Accep table Tolerance (m) gia tri 0.01 —* OK Nh$p md hinh tdu vao mddun AQWA ciia Ansys - Khdi dong Ansys Workbench -> chpn mgc Unit tren cdng eg de thilt lap hp dan vj - * chpn cdc myc Metric (kg, m,s, ) vd Display Values in Project Units (hinh 4) - Nhap dfli chudt hogc nhap va keo t h i mgc Hydrodynamic Diffraction cua mddun AQWA tir hpp Toolbox cua Workbench vdo viing Project Schematic (hinh 5) [1] E"re«^J HEUc(ton^MA^:JMAM] B FtiadnimpVLTFlilvq Q KanMflkRespcrBe I I Hinh Thiet lap he dffn vi - Nhip chuflt phii vao Geometry - * Import Geometry —* Browse -^ dipn tap tin mo hinh t i u da dung Autoship — ehpn mgc Edit Geometry de md Design Modeler - * chpn meter td dan vj d i i l u ddi —* OK de nhgp md hinh tdu vdo mdi trudng Hydrodynamic Diffraction - Design Modeler —* chpn d Detais Viewva thay doi cde mgc Simplify Topology: Yes —> Tolerance: Loose d l cd the sii'a loi tap hn ,igs —* Chpn mgc Generate Qe tao ta mo hinh hinh hpc Design Modeler Xac djnh mit phang dirong nirdc vd duvng nirdc - Cat mo hinh tdu d vt tri mdn nudc de phdn chia thdnh hai mfli tnfdng nudc - khdng bdng Binh Xic djnh mit phang nuhi nDi^c tda Hinh Man hinh khoi dgng Hydrodynamic DUTraction cdch nhap chpn muc 7bo/s —* Freeze (giup hap nhit mfl hinh thdnh mflt phan ttr de ed the thuc hifin chue nang cdt - slice) -* mfl hinh se trd nfin suit —» Djnh nghTa mdn nude tdu bdng cdch nhap myc Creat —* Slice —» chgn XYPIane (chpn mat phang XY Idm mat thodng nham phan cdch mfli tnfdng nudc vd khflng khi) —»ehpn mgc Apply Irong o Base Plane hflp Details Wew-* nhip chpn Generate de hodn tat eac thti tgc (hinh 6) - Re vd nhap chuflt true Y de dua tdu ve mat phang ZX - • chpn myc BodyOpI Tree Outline —* nhgp vdo fl FD5 Z Offset gid tri -1 (xdc dinh vj tri mdn nudc) chia md hinh tau thdnh phin tren mgt nude vd dtfdi mat nifdc —* an Enter —* nhip Generate d l hodn t i t cdc thti tuc (hinh 7) Hinh XAc djnh mta nm^ tdu TRUONG OAI HOC NHA TRANG • 79 Tgp chi Khoa hgc - Cong nghg Thdy sdn Thiet lgp cdc thdng so v$t ly cho md hinh md phdng - Trong hflp Hydrodynamic Diffraction nhip dfli chuflt vdo mye Model de nh^p mfl hinh tdu vdo mot trudng eua Hydrodynamic Diffraction (ANSYS AQWA - HYDRO - DIFFRACT) - Thilt Igp hodc bo sung cdc thong so v$t ly ciia md hinh tdu dang xdt d Details of Geometry, dd t l i thilu cin phil chpn thdng s6 Point Masses (PMAS) d l md td ma trgn khot tupng tdu D i i vdt moi mfl hinh tdu hogc m^t elu triic xdc djnh can cung cap mflt y i u t l khii lupng dilm Dilm ndy dupe chdn cdy tap hpp ede phin tir tdu bdng cdch nhip chuflt phii mgc Ship Hull -»Add - * Point Mass (htnh 8) ddy cfl hai tiiy chpn: Hinh Cach gan kh6i luyng cho mo hinh tan Chia ludi (Mesh) - Thilt lgp thflng so ludi bang cdeh nhap phdt Mesh Outline vd nhip vdo d Details of Mesh gtd trj Defeaturing Tolerance = 0.5, Max Element Size = 0.9, chpn Meshing Type la Program Con^ro/teddlchuangtrinhty kilm soit vific chia ludi Tilp tyc nhap phdi muc Mesh mue Outline —t chpn General Mesh d l chuang trinh ty dflng tao ludi So 3/2014 Nhdp tnj'c tilp g i i trj khoi lupng t i u bing cddi nhip vdo myc Point Mass fl Tree Outline vh nh$p trye tilp cdc gid tri c;ln thtet vdo d Details of Point Mass V( dg, chpn gid tri quin tinh khll lupng l i via Radius of Gyration d l nhap trye tiep dO Ii$u vdo Tfnh ty dflng khdi lupng tdu dya vao chuyen dflng ctia tdu bing cdch chpn d Mass Definiton 1^ Program Controlled (tuc chuang trinh kilm sodt) vd nhdp cdc s6 li|u Z (VCG) = - 4m vd gid trj cdc h^ s6 nudc kdm theo (hinh 9), dupc xdc djnh theo d^ nghj ciia chuang trinh Id [1] k = 0.34B = 0.34x6 =2.04 k^ = 0.25L = 0.25x25 = 6.25 k „ = 0.26L = 0.26x25 = 6.50 Hinh Nh^p 0A tri khoi Im^g cho mo hinh tdu chia cho mfl hinh tdu (hinh 10) Cfl t h l thay doi thong so de tgo Igi ludi chia nhung luu y Itfdi cang nhd, dO chfnh xic eao nhung q u i trinh ttnh se rit Idu, do nfin ehpn kfch thtfde ludi chia cho phil hpp [1], - Nhap vdo myc Units tren cong cu 6i djnh dgng Igi h0 dan vi cho bit toin, luu y thay dot tan s6 tir rad/s sang Hz DeUltKHegt Nut Iksli DtMl^TddVCt m UnBBHiSzt Ui MsjVmdFiniiitn m«i UohngT)])! nOfnCconu GenenledllUilnfHnliaii HriHuilUt) i MsiidaBU JntEfflKocspIt, I MefofSnirtil Hinh 10 Chia laM mo hinh 80 • TRUONG DAI HOC NHA TRANG !•• Tgp chi Khoa hoc - Cong nghg Thuy sdn Tfnh toan v i phdn tfch (Analyze) D i n diy, mfl hinh tdu khio sdt dd dupe chuan bj san sdng cho vt0c tfnh vd phdn tieh thiiy ddng tyc hpe vdi cac cflng eg dimg c i n thilt da cd san mgc Outline nhu Analysis Settings (Thilt l§p cac phdn tfch), Structure Selection (Lya chpn ket cau), IVave Directions (hudng song) So 3/2014 Wave Frequencies (tin so sflng) VI dy hinh 11 Id menu nh$p g i i tq ede thdng s6 sdng dilu hda vdt t i n s6 0.538 Hz, chilu cao sflng 0.25 m Bgn cung ed t h l nhdp vdo gia trj cdc tan s6 vd chu k^ sdng khic d l tgo thdnh hfi thing sdng nglu nhifin tdc dyng Ifin tdu nhu da trinh bdy phin trfin {hinh 12) \ ^^^^^^^^^^^^^^^^^^1 StniduretRer aRtmselecllaii SI*M Fitquency 0,5MHZ hciuMHefMflngStrsYes DRGIOA 0" Rfisul StfecUon MSaiVimtiif/L mn Raoul Type Cjtfc Dncnn WMPsgiiw(PtiiH) InalrtWiviAiit., 3,t7M;OOi«4eSE.02H2 «.649r6l]7Wt46E«IU RtKlTypg l,42106SIi02ieD3E42Hz WMPo!lon(PliBe) 0,i2imHi2tii4eiu aConloirStieclta SMInCortwTy, HHPOtMMisin 10,011 H: Q / t m « M e f o d y n HnNd PKSSUR MttStRIMf H e r i o l V M WMCoilMTyi)) WkvBHel^ B CoapoMntSeleclioa Hinh 11 Menu nhap cic th&ng s^ sdng Sif dyng eong eu Solve Hydrostatics hoae nhip phii mgc Hydrodynamic vdt hai tiiy chon (hinh 12): - Calculate hydios^es only (compute disf^acement and smalt angle stability parameters) dting de tinh todn thuy tmh, gom tinh todn lifpng chiem nude vd cac thflng so on dinh d gdc nghieng nho - Compute full hydrodynamic properties and results dung tfnh day dii thiiy dpng lyc hpe Trong qud trinh phin tfdl, chting ta cfl the chen AmWaterBodyDl DOHd Prassure M«B9iflSDBnlj Head o( Water Hinh 12 Menu nhSp cac tan so song khac thfim nhu-ng tiiy chpn d l xult cac kit qua tinh todn Dilu ndy cfl the dupe thye hifin tnrdc hodc thye hifln sau qud trinh phdn tieh mo hinh da thyc hifin xong Cdc kit qua tinh cd san gom cd Hydrostatic, Hydrodynamic Pressures and Motions v i cdc kit qua chen &iem nhu Hydrostatic Table (Bang tinh thuy tinh), Hydrodynamic Graphs (Bieu thuy dgng Igv hgc) V V Ddnh gta tat c i kit q u i dipn lya v i trinh bdy hay e$p nhgt (presented/updated) (htnh 13) [1] S Hydrostatic Dilfractton * Froude-Kiylov Diffnction Proude-Kiykiv RcsponteAmpEtudeOpcnton (RAOs) FUdittion Damping Added Mast Steady Diift OiffcranccQTF SFy8M(aatie)|^ SF/BM(RAO)'' Splitting Fofces ^ PresHires and Motions ,;'fe !-j3SoUiM(BS) mnh 13 Chpn lin giil Hinh 14 Cic tiiy chQu tfnh thuy d^ng 1^ hpc tdu TRLTONG OAI HOC NHA TRANG • 81 Tgp chi Khoa hgc - Cong nghe Thuy sdn Xult ket qud - Lya chpn cdc tiiy chpn xuat k i t qud cd trdn Properties vd Hydrodynamic graphs (hinh 15) d l xult ket q u i tinh hogc cdc d l thj vd hinh dnh tuang trng vl dg nhu k i t qua tfnh cdc yeu t l So 3/2014 thCiy tmh (Hydrostatics) (hinh 15), thj bien Qfy dao dflng eiia tdu {Response Amplitude Operators RAOs) (hinh 16), phdn b l dp suit thtiy dflng lyc hpc (Hydrodynamic pressures) (hinh 17) v i c i c chuyin dpng cOa t i u trfin sdng (motions) (hinh 18) [2] Hinh 18 Hinh anh phdn b^ cic $6ng xung quanh ch.'in lau chii\£n d^ni- 82 • TRUONG DAI HOC NHA TRANG Tgp chi Khoa hoc - Cong nghe Thuy sdn IV KfeT LUAN Kit q u i nghifin cuu cho phdp rut mflt s6 ket lu$n sau: - Khd nang su dyng k i t hpp phan mem thiet ke tdu Autoship vd phin mlm phdn tich CFD Id AQWA ANSYS d l thyc hifin md phdng vd phan tich thiiy dflng lyc hpc cho b i i toin t i u chuyin dflng trfin sflng Id khd tht Ket qua cung da dupc chiing tfli su dyng d l khdo sdt mo hinh tdu da ed day du sd li#u thyc nghidm v i se dupc trinh bay cy t h l han bdt bdo tiep theo - K i t q u i nghifin eiru cung sfi Id ca sd quan trpng de giai quylt nhilu bai t o i n hifln van chua cd duyc phuang phdp nghien ctru va Idi giai chinh x i c nhu tinh sire can, phan tich dnh hudng ciia sdng bien, cua cdc tai trpng tren tdu, ke ca tdi Idng d i n chuyin ddng ctia tdu, anh hudng So 3/2014 ciia lie v v K i t qua nghifin eiru sfi md nhilu hudng nghifin ctru quan trpng iinh vyc ky thu|t tdu thuy, ITnh vyc van nhieu van d l chua dupe nghifin cuu trifit de bdi han c h l v l dleu kipn thyc nghtgm, t h i m cht nhilu trudng hpp Id khdng the thyc hipn dupc, nhat Id d dieu kifin ktnh t l - kJ thudt v l n nhieu han c h l nhu nudc ta hi§n - CFD ed vai trd vd y nghTa rat quan trpng, da vd dang dupc trng dyng rflng rai nhieu ITnh vyc Tuy nhien d nudc ta hifin d i y v l n cdn Id mflt ITnh vyc mdi vd chua cfl nhieu ket qud irng dgng Vi v$y ket qua nghifin cuu ciia d l t i i cung se Id ca sd d l phit triln fTnh vyc nghien cuu mdi me ndy cflng tdc nghifin ciru khoa hpc vd dao tao sau dgi hpc d khoa Ky Siugt giao thong eua Trudng Ogi hpe Nha Trang TAI Llgli THAM KHAO www.aiisys.coin/Products/Other /ANSYS+AQWA TrSn Gia Thai, 2014 Nghien dm ung dung phuong phap tinh toan dpng lyc bgc luu chat (CFD) mo phong so &k thay th6 mot s6 thyc nghiem nganh Ky thuat giao thong D6 tai nghien cuu khoa hoc cap truong, ma so TR2013-13-01 lYjln Gia Thai 2010 Tu dong hoafliietk6 tiu thuy NXB Khoa hpc vS Ky thuat TP H6ChiMiDii TRUONG DAI HOC NHA TRANG • 83