NGHIEN CU'U-TRAO D O I MO PHONG TRL ONG DONG C H A \ CL A NL C BAO QUANH THAN TAL BANG LV THL^ ET CFD SIMULATION OF FLUID FLOW AROUND SHIP HULL WITH CFD METHODS Le Van Toan' Tran Gia Thai' 'Trudng Dai hpc Giao thing Van tai TR HdChi Minh -Trudng Dai hpc Nha Trang TOM TAT Trong nghien cuu ndy chung tdi idp trung md phdng trudng dong chay cuu mrdc bao xung quanh vd tdu container sire cha 14.000 TEU theo cdch tiep can RA.\SE (Reynolds- Averaged \a\ lerStokes equation) Tren co sd tinh todn luc thuy dpng tdc dung len thdn tdu idu chuyen dpng deu nudc tinh: so sdnh kel qud tinh todn mo phdng CFD vdi kit qua thir nghiem be thu dd duac cdng bo Dong chay diroc xem chay roi, diroc md la bdi phuong trinh RA \S (Reynolds-Averaged \avierSt(ikes) md hinh rdi SST k-co Tir khoa: Sire cdn tdu thuy Dong luc hpc chdt ldng (CFD): Dpng lire hpc tdu container AB.STR.\Cr In this research, we focused on simulating the flow of water around container ship hull in according toRASSE approach (Reynolds-Averaged I4.000-TEU NavierSlokes equation) On that basis, we calculated the hydrodynamic forces exerting on the hull when making uniform motionin still water: then compared between tlieCFD simulation calculation results with the experimental results in the testing reserx'oir have been aniwunced The flow i\ considered turbulent, and described by the equation R.-i \S (Reynolds-Averaged \avierStokes) SST turbulence model k-w KIN « ords: Ship resistance: Computational fluid dynamics iCFD): Container ship hvdrodvih^"! < ISSN 6 - > TAP CHi CO KHi VIET NA.M S6 nam 2016 www cokhiv it' i n a m.vn NGHIEN c u u - T R A O D(!)l GIOI THIKl Hien nay, van tai dudng bien dong vai tro quan trpng lim thdng hang hoa toan cau dd loai tau chd container chiem phan Idn vi xu the thdi dai hang hda dugc chira cac thiing tieu chuan (container) nham tang nang suat lam hang ciing nhu kha nang bao quan va kidm soat ciia dich vu logistics Do vay, tinh tdi uu ve kinh ke dong v trd thiet ydu bai toan thidt kd tau va thudng lay cong suat may lam gia tri ham ldi uu, sire can lam rang bupc chinh Didu ndi len rang van de sire can tau luon la van dd thdi su, giir vai trd cdt ldi ham muc lieu ciia bai toan thiet kc tau Giai quydt van de sire can ndu trdn bang tinh toan md phdng sd thudng liep can thdng qua ldi giai ciia phucmg trinh chuydn dpng dong chat long khdng nen dupc bao xung quanh than tau phuang trinh Navier-Stokes Theo each lam truyen thong, ngudi la gia djnh rang, chat Idng khdng cd tinh nhdt, lidn tuc, khdng nen dugc va dong chat, nham dan gian hda phuang trinh Nav icr-Stokes ve dang ham the van tdc viet bdi phuang trinh Laplace Cach lam nay.chi hop ly vdi thdi diem nhiing nam 2000: nav \di su phat trien manh ciia cdng nghe may tinh -": "-^ ,t cac phuang phap tlnh phirc tap va tidu tdn nhidu tai nguyen khdng cdn la trd ngai, thi phan dp nhdt cua nudc phuang trinh Navier-Stokes khong dugc bd qua tinh loan nham tang dp chinh xac ciia kdt qua tinh Vi ly do, cdng trinh nghien cuu na\ chiing tdi chpn each tiep can theo RANS dd dien giai phuang trinh NavierSlokes cho ddng chat Idng (nudc) chuyen dpng bao quanh than tau ket hgp md hinh rdi SST k-co Chpn OpenPOAM lam cdng cu tinh toan md phong.day la nhihig gdi ma nguon md da dugc chap nhan rpng rai bdi cpng dong CFD, ca gidi hpc thuat va cdng nghiep Tau mau diing nghidn cim la loai tau container sire chd 14,000 TEU dupc thiel ke, thir nghidm bdi Vien Ky thuat Tau thiiy va Giao thdng Hang hai ISMT (the Institute of Ship Technology, Ocean Engineering and Transport Systems, ISMT) Thdng sd va van tdc chuydn ddng tau mo hinh nghidn cuu nhan gia tri triing vdi gia trj da thir nghidm md hinh dupe cdng bd [2], de thuan igi viec so sanh kdt qua nghidn curu, cho Bang 1.1 / J Hinh L L Tuyen hinh tdu container iSSN 0866-7056 TAP CHi CO KHi VIET NAM, Sd nam 2016 ww"W.cokhiv ietnam.vn [2] NGHIEN CU'U-TRAOOOl Bdng 1.1 Thdng sd tdu TT Thong s6 Ky hi|u Dffn vj Lp, m m m m m' Chieu dai dai tru Chieu rgng tau Chieu rong duong nunc Chieu chim tau The tich chiem nuoc He so day the tich Di?n tich mat uot Van toe tau u u mhlh m/s So Froude F - B B„ d V f„ S Gii tri Tau thirc Mo hinh 355.0 5.976 859 51.0 0.859 51.0 0.244 14.5 0.827 173467.0 0.661 0.661 6.243 22032.0 3.244 25.0 1.669 12.9 0.2 IS 0.218 C O SO L V T H L V E T trung binh va dao dpng Trudng dong luu chat chuydn dpng quanh than tau dupc mo ta bdi hai phuang dinh chii dao: Phuang trinh lidn tuc va phuang trinh Navier-Stokes viet theo each tiep can RANS, d dd cac dai lugng vat Iy mang y nghia trung binh [l].Bai toan dugc giai bang each ket hop phuang trinh RANS vdi phuang trinh trang thai md hinh rdi theo de xuat ctia Menter mang ten SST k-ftj[l] P ap lyc trxmg binh; p va v la mat dp va dp nhdt dpng hpc ciia chat long Phuang trinh lien tuc: ^ =0 (1.1) f.V, Phuang trinh ddng lupng: i(v,L'} dU cl^ Bd mat ty (giao cua hai pha nudc) dugc \ u ly bang phuang phap the tich chat luu (VOF) dya tren ca sd ham Hen kdt a(x, t) giura hai pha a(x, t) e [0,1] bidu dien cac trang thai ciia luu chat moi d Khi md phdng than tau, a ^ bidu chi rang nudc lap day toan bp cac d, cdn a ^ cd nghTa la cac d dupc chira day khdng M(^.t)-u , a + M ^ ^ ^ , ( l - a ) (1.3) p ( \ i ) - u ,^a + ^ij^^-„^y„(l-a) (1 4) K E T Q L \ NGHILN C I I (1.2) 3.1 Xac lap dir lieu dau vao ciia bai toan Trong do: L \ a « ] : Cac phan van tdc Xa\ dung hinh hpc tau 3D vdi cau tnic theo dinh dang *.stl nhu hinh 1.2 « ISSN 0866-7056 TAP CHi CO KHi M E T NAM, S6 nam 2016 www.cokhiv t'jinam.vn NGHIEN c u u - T R A O e l rdi rac khdng gian midn tinh thdng qua mo dun ma snappyHcxMesh va ket ndi vdi ludi tam giac hinh hpc vo tau theo dang *.stl dd hinh ndn midn rdi rac tinh toan hoan chinh Hinh 1.2 Hmh hgc 3D cua tdu container Bai toan dupc giai dya trdn bd giai InterFoam vdi cac thiet lap nhu sau: Khdng gian mien tinh toan dugc xac lap tai cac vi tri nhuhinhl-3 •Ap dai cac didu kidn ban dau (van tdc linh loan, cac he sd cua phuang trinh trang thai) va cac didu kien bien vat iy ciia bai toan, nham khep kin he phuang yinh md phdng trudng ddng va thyc hidn giai vdi thuat giai PIMPLE bp giai InterFoam danh cho loai moi trudng pha luu chat khdng nen dupc, cd tinh nhdt Hinh 1.4 Lmri tinh todn Hinh ^ Khong gum micii Hnh loan Su dung phuang phap ludi the tich Didu kidn bien v at ly tinh loan cho Bang 1.2 Bdng Dac tinh ciia bien K> hi^u Top hllO! Oulk-I Skies tiu Horn MiJPianc Hull Tinh chat bien Patch, faces • Palch laces Palch tjccs i S\mnielr) Plane, faces , S\mnielr\ Plane, laces S\ninietr\ Plane, laces • Wall riinction I Fixed value Fixed value Gradient = Fixed value Fixed value Symmetry U=0 e p = p Gradient = Gradient = Gradient = P = P, Symmetry Gradient = k, 01 Gradient = Fixed value Gradient = Gradient = Gradient = Symmetry Wall function 3.2 Ket qua tinh toan va mo phong Lyc va mo men thuy ddng tac dung Idn tau cd gia tri cho Bang 1.3 ISSN 0866-7056 TAP CHi CO KHi VIET NAM Sd nam 2016 www.cokhiviftnam.vn NGHIEN CU'U - TRAO D O I Bang 1.3 Luc vd mdmen thuy ddng linh theo CFD tgi Fn = 1/21A Toe dp chuyen dong tau I = 1.668 m/s z X Phuong Lire thdy dong N -2.90017 Luc ap suat 3913.85 1612.72 -0.184994 -12.6327 Mdmen thiiy dnn^' N \ N % Gia tri tinh 5.80 25 27 31.07 31.83 2.40 Cac truimg ap suat (hinh e,0, trudng van toe (hinh a,b,c), trudng rdi (hinh d) ciia tau nhu trinh bay trdn hinh 1.5 "^WZ- 0-**-^ r'"'^"! Hinh I Cdc tnrdng vgt ly unh loan ISSN 0866-70S6 TAP CHi CO KHi VIET NA.\L S6 nam 2016 www.cokhiv ietnam.vn NGHIEN cuu-TRAO 06l thang day phang va tuang ddi manh (L B^6.960) nhu tau linh toan K E T L l AN 4.1 Triromg vat l> nudc bao xung quanh than tau Tir ket qua tinh toan md phdng nhu hinh 1.5 thav rang- Trudng vat 1>' nudc bao xung quanh than lau hoan toan hgp Iv v a phii hpp ly thuyet dpng lyc hpc luu chat, cu the nhu sau: - Trudng ap suat dat gia tri cao tai vimg mui tau lai tau va giiia tau (hinh 1.5 e vaO: - Viing ngav sau lai tau xual hien ddng chay ngupc la hien tupng ddng theo tinh thd ciia nudc (hinh 1.5 c); 4.2 Ket qua tinh luc thdy dpng Vdi ket qua tinh loan va so sanh nhu trinh bay d Bang 1.4 thay ring: Md hinh toan tinh loan ciing nhu phucmg phap giai dang tin ca> sai sd dat dupc la 2.40"o.*;* Ngav nhan bai: 05/8/2016 Ngav phan bien: U/9/20I6 Tai li|u tham khao: [1] [2] - Hidn tugng rdi dong dugc da> ngoai viing tidp giap than tau va nudc xay tai viing vdt thuv dpng theo sau tau (hinh 1,5 d) Dieu hgp ly vdi dang tau man F Moukalled L Mangani M Darwish (2015) 'Tluid Mechanics and Its Applications" Springer Quid el Moctarl* Vladimir Shigunov2 Tobias Zom2 (2012) "Duisburg Test Case: Post-PanamaxContainer Ship for Benchmarking" Ship Technology Research Schiffstechnik 59(3), pp 50-64 ISSN 0866 7056 TAP CHi CO KHi VIET NAM, Sd nam 2016 www.cokhivictnam.vn ... toan K E T L l AN 4.1 Triromg vat l> nudc bao xung quanh than tau Tir ket qua tinh toan md phdng nhu hinh 1.5 thav rang- Trudng vat 1>'' nudc bao xung quanh than lau hoan toan hgp Iv v a phii hpp... (nudc) chuyen dpng bao quanh than tau ket hgp md hinh rdi SST k-co Chpn OpenPOAM lam cdng cu tinh toan md phong.day la nhihig gdi ma nguon md da dugc chap nhan rpng rai bdi cpng dong CFD, ca gidi hpc... 26.5324 430.29S 3.04808 -3.81958 So sanh kdt qua tinh theo CFD va kdt qua thii nghiem trinh bay Bang 1.4 Bdng 1.4 So sdnh ket qud tinh theo CFD vd ket qud thir nghiem [2] TT -1 Sue can Siic can Siic