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Study on the Prediction of Flow Characteristics Around a Ship Hull
Pages 927-940

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From page 927... ... Han (Hyundai Heavy ludustrie s Korea) ABSTRACT A long temm R & D :' og am on She predicts m of flow characteristics around c ship hull has ~ en e tablished with She aim of preparing c suffcie tly accurate computational medhod for practical application This program is c mposed of 3 tage st dies The Ist tage st dy on She Investigation of th state of art of CFD technology has been carried out For this purpose, 4 CFD cod s w re selected Using th selected codes, mmmerical computations have bean pert:3rrned for 5 different ships in 4 different ship types together with She experimental measmements Th c mparisons between the e perime tat results Ed th results of c mputation show that present CFD technology need to be farther improved for practical application INTRODUCTION b or r to improve She hyd odynamic perfommance of c ship, it is necessary to have th k owledge on She -I w characteristics around c ship hull Ed to utilize th k owledge in d sign Two medhod are cvaibble to predict the flow characteristics one is the experimental method, that is, model test, Ed th other is She computational method so called c mputational fluid dynamics(CFD) Read the entire page →
From page 928... ... P Re, u~u, xc fhe velocity, piezomehic pressme, Rey olds No, md Rey old shess ~e pectively b ordx to p~edict t rbule t flows vie fhe quctions, it becomes necessary to mcke closme assmmptiom about the Rey olds t~ess, becmse fhe quctions do not comtit te c closed set The turbulence mod is md process of exp~essi g fhe Rey olds shesses m temms of th Imow qumtities cm be categorized mto Rey olds t~ess model RSM md eddy viscosity mod I dVt~ b RSM, fhe partial differenticl eq cti ms f x fhe Rey olds st~esses xc fxmuLted md solved The RSM mclud s the effect of some impxtmt factors, such as fhe t~eamlme curvat ~e md th body fmce et, m the chxactxistics of the t rbulence, but r qui~es cdditional computation to solve the particl differential quctions for fhe each components of fhe st~ess Furfh xmme it is still necessary to model some of t xms m th u equatims Altxnatively algeb~aic shess mod l(ASM using th algebrcic equati ms imtecd of fhe particl diffxe tial eq ctions, on the cssumption f tt cor~ctive md diffusion txms m RSM is Imexly d pendent on fhe t rbulence kinetic ffUxgy k c m be mpliedto sevexal e gmexi g felds b the E M, based on fhe Boussmesq's hypothesis, fhe Rey old t~esses me ~ep~ese ted es m m velocity g~adients The E M are ckssed i to zero, one, md two quction models according to fhe m mber of partial diffe~e tial eq ctiom Th mo t wid Iy used model in engmeermg mplicati ms is fhe k~ model m conjm tion wifh fhe wall fm ti m m teed of fhe fne meshes near the wall surtcces b sol mg flow pattems arommd 3 dimem iom~l bodies, it is convenient to use fhe boundxy fitted Coordinate sy tem The particl diffxenticl quction to h msfomm fhe phy iccl domcm i to fhe computatiorul domcm mu t be solved, govexnmg qucti ms clso be h msfommed This t m f xmation m be divided i to two way: one is thct both ge metriccl md phy ical variables a~e trm fommed The oth r is that only geometrical variables me tr m fommed From fhe Read the entire page →
From page 929... ... Th se fie w fiKe bommdary conditions zre wnlinear imd fhey hav to be zpplied zt im imtially mDcoow su fiKe iteration procedwre, usmg fhe solution on Imeari cd bwwndiny conditimms, xc geruxally zdopted SELECTION OF CODES For fhe rake of univxwl validbty of this tudy, totcl 4 codes w re selected, fwrt is 3 w 11 k ow commemial code(STAb CD, FLU NT, SH FFLOW) imd HMK code The chxiKteri tics of eiKh code hcs been summarized m T wle I Tzble I Chara>teri om _ Govemimd equ dion _ TurbMenoe model _ Near wall FF di~ _ di6ereh dMn Grid 6Z tem _ Variable la~out Velooit~ Fremure t oouFlmd _ NS: Full NS Zonal: Fote tial/loteg z~Full NS bE:Stmdxdkd MKE:Modiftedkd WF: Wzll fwoction 5: Shw tmed SG: Stzggxed Charactxi tics of CFD Codes EMKI NF KE WF FVM s FG FIMFLE FLUENT NF MKE WF FVM us NG UMFLE US: Un tmctmed NG:Non stcgge~ed Read the entire page →
From page 930... ... For the global wa~4 elevation mewmv4ments, fhe longit ddrul cut method ww utili cd Fom wa~4 gmges of ccpm itY e t pe wifh 50 mm interval w4'e tied up m om4 umt, so f 4t four Imes of wa~4 elevation date were obbmed in c smgle ma This holder ww mo~4d clong c tmss CttY hed et the sidewall of the t mk Triggermg signal is provided by m opticcl wit h 4t 4 62 m be4d of FF to id ntify the location For th local waw4 elevati m mewmv4ments, fhe prolx4 of servo edle type ww cttsched 4t c ha~4rsi g mechmism md incliru4d by 45� to be Y 4ssible To mex re th waw4 elevation along the h 11 x rface, th ee pers ms ~ecdthe waw4 profile mdthe aver4ge was bkff For the local velocity mecY r ments, c rYke wifh fl~4 Sbole Fitot tulx4s ww ux4d The 5 hole Fitot t be h4d sphericcl tip wifh 6 mm in d64meter md th mgle betweff~ w4s of cc ter hole md side holes ww 30� Esch tube was com eted to c p~v4ssmv4 h msd cer Th kiru4matic calibrati m r mge of th Fitot t bes ww +30� of pit h md yaw mgle if the flow mgle to lx4 mesmv4d was out of the calibration r mge, fhe date was d6xorded The mexr ments w4'e cYried out across fhe cente pb~4 to confum th symmeby of flow Th verticcl holes to fhe h 11 smiace wifh 3 mm m dYmeter were piemed for the meemv4ments of fhe hull presx re The holes were on fhe keel Ime md m th sbtion 2 md stati m I with 20 mm spacing Th flow liru4s on the h 11 were lsualized usmg pal t The paint was Ym cpproprYte ml tme of dy, oil pcmt, wax, Ymd fhl mer Th optimum mixmg mte will lx4 obtamed fiom the try md error Uueertehty eu~dysls Th m erbmty ar3~ly is for fhe resistY e tex we perfommed by fhe ~ec mmff~dation of fhe 22 4 ITTC resist m 4 c mmittee For the oth r texs, the bie Ymd precision errors of th g mges; Ymd precision en ors of fhe meemv4me ts w4'e m~4stigated Th accurm y of the model geomeby LB,d) Read the entire page →
From page 931... ... w t loc tted et St 19 5 md middle of fhe bulb for fhe ship mod is havmg bow bulbs For fhe d shoy r model with t bulb, t rbulent stimulltors were located tt 50 mm offthe bow Th sccle r ttioO of fhe model ships is 47 56, 36815, 14959, 37441, md 276 for 300,00 TDW V CC, 170,000 TDW buk carrier, 6,300 m LFG carrier, 4,200 TEU contamer carrier, md 5,000 torme d shoy r, t spect~vely Tcble 4 Frmcipcl Farticukr s of the Object Ships 300,000 TDW 170,000 TDW 6,300 m' 4,200 TEU 5,000 tocce VLCC bulk carrier LPG mrrier coct dner csuier destroyer L~(m) Read the entire page →
From page 932... ... 5,000 tom Ck ss Desh oy r Fig 2 BodyPkms mdSid Profiles The selected CPD codes md fhe flow characteri tics to be ccicuhted or measut d have been smmmari ed m Table 5 C mputttiom md measut me ts have ben conducted acccrd6ng to Table 5 for each of 5 d6ffet t ships, md c vc t amou t of mfcrmation for fhe flow characteri tics have beert pt pared mong fh m, fhe followmg characteri tics shcil be presented selectively: resi tance profile wave elev tti m loccl resi tance velocitydi tribution limitmg stt tmlit pt ssme di tribution wake( tt the prop ller plane) Tcble 5 CPD Cod s md Characteristic to Be Cal tk ted or Mec tred Chsrscteristics H C P Viscous O O O Resishace Wave X X X Oversil X X X Protile X X X ElW~s~vtleon Locsl X X X Glob~ X X X Locsl resishace O X X Limiting stresm ice O O O Velocih distriLctioc O O O Presscre distriLctioc O O O Bocads y Isyer O O O Wske O O O _ _ b Tcble 5, fhe symbols of H Read the entire page →
From page 933... ... , k md CFM represe t fomm factm md fi ictiot~l resi tance coefficient, respectively b c mputatimurl analy is, iscous resistance c tld be comidet d to be composed of two tt ss c mponents which are pemerldicular md t mgential to fhe ship hull, t sp ctively Whert twm tress coefficients perperldicular to md t mgential to fhe hull me denoted by Cv~ md CVF, vise ts resist mce coefhcie t c m be obtamed as follows: c~U = c>7 +c~ = 1(cy~ +c~ Kind ot Ship 300,000 TDW VLCC 1 70,000 TDW bulk mrrier 6,300 m3 LPG mrrier 4,200 TEU cochmer mrrler 5,000 tocce destroyer (withoct sppecdsges) Read the entire page →
From page 934... ... Table 7 Resist mce Characteri tics Model Scale) Kind of Ship Test Condition Medhod C Mxto3 C Mxto3 CwxlO C Mxto3 Model test 3 841 0 042 3 883 LM =6 728 m E~1 3 662 300, 0 TDW :1 6 m/s STAR CD 3 174 3 800 Fn =0 142 FLllENT 4 034 SE FFL W 3 581 0 473 4 054 Model test 3 737 0 047 3 784 LM=7 551 m E~1 3 706 170,000 TDW 1 272 m/s bulkcarne R :097 10 STAR CD 3006 4312 Fn=0 147 FLllENT 2 918 SE FFL W 3 363 0 365 3 728 Model test 3 705 2 475 6 180 LM=6578m E~1 3 112 LFG car ~er ~t 995 m/s STAR CD 2 976 3 536 Fn =0 249 FLllENT 3 853 SE FFL W 3 364 3 339 6 703 Model test 3 038 0 24 3 277 LM=6 942 E~1 3 279 4,200 TEU 2 018 m/s co tamercarrier R ~ 40 10 STAR CD 2821 2997 Fn =0 239 FLllENT 3 338 SE FFL W 3 141 0 824 3 965 Model test 3 340 2 545 5 885 5,000 tom~e LM =5 0 m E~1 4 875 d~sp=nt :2 98t m/s STAR CD 2 952 3 230 (w6-ho t Fn =0 425 FLllENT 3 364 SE FFL W 3 362 2 384 5 746 Read the entire page →
From page 935... ... 4,200 TEU Co tamer Carrier Fig 3 Comparison of Profile Wave Elevati m Fig 4 shows th local resistance coeffcie 33 predicted by HtdRI cod Since it was not possible to be calculated by ocher codes, comparison could not be made How ver, it could be d duced Fiat fihe c mponent d e to pe pff~dicular to ship hull is dominent m th foreyard md oft pants while th component due to Fiction is domment m fihe middle Begun ~ . Read the entire page →
From page 936... ... SHIPFLOW Fig. 5 Axial Velocity Contours of 30O,000 TDW VLCC at the Station 1 (x=0.95) Read the entire page →
From page 937... ... SHIPFLOW Fig. 6 Limiting Streamlines for 6,300 m3 LPG Carrier Read the entire page →
From page 938... ... SHIPFLOW Fig. 7 Pressure Contours on the Hull for 17O,OOO TDW Bulk Carrier Read the entire page →
From page 939... ... 9 and 10 show the axial velocity contours(wake) and velocity vectors on the propeller plane for 17O,OOO TDW bulk carrier and 4,2000 TEU container carrier. Read the entire page →
From page 940... ... FLUENT 0.~ r/R 0.0 Fig. 10 Axial Velocity Contours and Velocity Vectors on the Propeller Plane for 4,200 TEU Container Carrier CONCLUSIONS The flow characteristics around a ship hull were investigated through the numerical and experimental methods. Read the entire page →

From page 927...

... Han (Hyundai Heavy ludustrie s Korea) ABSTRACT A long temm R & D :' og am on She predicts m of flow characteristics around c ship hull has ~ en e tablished with She aim of preparing c suffcie tly accurate computational medhod for practical application This program is c mposed of 3 tage st dies The Ist tage st dy on She Investigation of th state of art of CFD technology has been carried out For this purpose, 4 CFD cod s w re selected Using th selected codes, mmmerical computations have bean pert:3rrned for 5 different ships in 4 different ship types together with She experimental measmements Th c mparisons between the e perime tat results Ed th results of c mputation show that present CFD technology need to be farther improved for practical application INTRODUCTION b or r to improve She hyd odynamic perfommance of c ship, it is necessary to have th k owledge on She -I w characteristics around c ship hull Ed to utilize th k owledge in d sign Two medhod are cvaibble to predict the flow characteristics one is the experimental method, that is, model test, Ed th other is She computational method so called c mputational fluid dynamics(CFD)

Read the entire page →

From page 928...

... P Re, u~u, xc fhe velocity, piezomehic pressme, Rey olds No, md Rey old shess ~e pectively b ordx to p~edict t rbule t flows vie fhe quctions, it becomes necessary to mcke closme assmmptiom about the Rey olds t~ess, becmse fhe quctions do not comtit te c closed set The turbulence mod is md process of exp~essi g fhe Rey olds shesses m temms of th Imow qumtities cm be categorized mto Rey olds t~ess model RSM md eddy viscosity mod I dVt~ b RSM, fhe partial differenticl eq cti ms f x fhe Rey olds st~esses xc fxmuLted md solved The RSM mclud s the effect of some impxtmt factors, such as fhe t~eamlme curvat ~e md th body fmce et, m the chxactxistics of the t rbulence, but r qui~es cdditional computation to solve the particl differential quctions for fhe each components of fhe st~ess Furfh xmme it is still necessary to model some of t xms m th u equatims Altxnatively algeb~aic shess mod l(ASM using th algebrcic equati ms imtecd of fhe particl diffxe tial eq ctions, on the cssumption f tt cor~ctive md diffusion txms m RSM is Imexly d pendent on fhe t rbulence kinetic ffUxgy k c m be mpliedto sevexal e gmexi g felds b the E M, based on fhe Boussmesq's hypothesis, fhe Rey old t~esses me ~ep~ese ted es m m velocity g~adients The E M are ckssed i to zero, one, md two quction models according to fhe m mber of partial diffe~e tial eq ctiom Th mo t wid Iy used model in engmeermg mplicati ms is fhe k~ model m conjm tion wifh fhe wall fm ti m m teed of fhe fne meshes near the wall surtcces b sol mg flow pattems arommd 3 dimem iom~l bodies, it is convenient to use fhe boundxy fitted Coordinate sy tem The particl diffxenticl quction to h msfomm fhe phy iccl domcm i to fhe computatiorul domcm mu t be solved, govexnmg qucti ms clso be h msfommed This t m f xmation m be divided i to two way: one is thct both ge metriccl md phy ical variables a~e trm fommed The oth r is that only geometrical variables me tr m fommed From fhe

Read the entire page →

From page 929...

... Th se fie w fiKe bommdary conditions zre wnlinear imd fhey hav to be zpplied zt im imtially mDcoow su fiKe iteration procedwre, usmg fhe solution on Imeari cd bwwndiny conditimms, xc geruxally zdopted SELECTION OF CODES For fhe rake of univxwl validbty of this tudy, totcl 4 codes w re selected, fwrt is 3 w 11 k ow commemial code(STAb CD, FLU NT, SH FFLOW) imd HMK code The chxiKteri tics of eiKh code hcs been summarized m T wle I Tzble I Chara>teri om _ Govemimd equ dion _ TurbMenoe model _ Near wall FF di~ _ di6ereh dMn Grid 6Z tem _ Variable la~out Velooit~ Fremure t oouFlmd _ NS: Full NS Zonal: Fote tial/loteg z~Full NS bE:Stmdxdkd MKE:Modiftedkd WF: Wzll fwoction 5: Shw tmed SG: Stzggxed Charactxi tics of CFD Codes EMKI NF KE WF FVM s FG FIMFLE FLUENT NF MKE WF FVM us NG UMFLE US: Un tmctmed NG:Non stcgge~ed

Read the entire page →

From page 930...

... For the global wa~4 elevation mewmv4ments, fhe longit ddrul cut method ww utili cd Fom wa~4 gmges of ccpm itY e t pe wifh 50 mm interval w4'e tied up m om4 umt, so f 4t four Imes of wa~4 elevation date were obbmed in c smgle ma This holder ww mo~4d clong c tmss CttY hed et the sidewall of the t mk Triggermg signal is provided by m opticcl wit h 4t 4 62 m be4d of FF to id ntify the location For th local waw4 elevati m mewmv4ments, fhe prolx4 of servo edle type ww cttsched 4t c ha~4rsi g mechmism md incliru4d by 45� to be Y 4ssible To mex re th waw4 elevation along the h 11 x rface, th ee pers ms ~ecdthe waw4 profile mdthe aver4ge was bkff For the local velocity mecY r ments, c rYke wifh fl~4 Sbole Fitot tulx4s ww ux4d The 5 hole Fitot t be h4d sphericcl tip wifh 6 mm in d64meter md th mgle betweff~ w4s of cc ter hole md side holes ww 30� Esch tube was com eted to c p~v4ssmv4 h msd cer Th kiru4matic calibrati m r mge of th Fitot t bes ww +30� of pit h md yaw mgle if the flow mgle to lx4 mesmv4d was out of the calibration r mge, fhe date was d6xorded The mexr ments w4'e cYried out across fhe cente pb~4 to confum th symmeby of flow Th verticcl holes to fhe h 11 smiace wifh 3 mm m dYmeter were piemed for the meemv4ments of fhe hull presx re The holes were on fhe keel Ime md m th sbtion 2 md stati m I with 20 mm spacing Th flow liru4s on the h 11 were lsualized usmg pal t The paint was Ym cpproprYte ml tme of dy, oil pcmt, wax, Ymd fhl mer Th optimum mixmg mte will lx4 obtamed fiom the try md error Uueertehty eu~dysls Th m erbmty ar3~ly is for fhe resistY e tex we perfommed by fhe ~ec mmff~dation of fhe 22 4 ITTC resist m 4 c mmittee For the oth r texs, the bie Ymd precision errors of th g mges; Ymd precision en ors of fhe meemv4me ts w4'e m~4stigated Th accurm y of the model geomeby LB,d)

Read the entire page →

From page 931...

... w t loc tted et St 19 5 md middle of fhe bulb for fhe ship mod is havmg bow bulbs For fhe d shoy r model with t bulb, t rbulent stimulltors were located tt 50 mm offthe bow Th sccle r ttioO of fhe model ships is 47 56, 36815, 14959, 37441, md 276 for 300,00 TDW V CC, 170,000 TDW buk carrier, 6,300 m LFG carrier, 4,200 TEU contamer carrier, md 5,000 torme d shoy r, t spect~vely Tcble 4 Frmcipcl Farticukr s of the Object Ships 300,000 TDW 170,000 TDW 6,300 m' 4,200 TEU 5,000 tocce VLCC bulk carrier LPG mrrier coct dner csuier destroyer L~(m)

Read the entire page →

From page 932...

... 5,000 tom Ck ss Desh oy r Fig 2 BodyPkms mdSid Profiles The selected CPD codes md fhe flow characteri tics to be ccicuhted or measut d have been smmmari ed m Table 5 C mputttiom md measut me ts have ben conducted acccrd6ng to Table 5 for each of 5 d6ffet t ships, md c vc t amou t of mfcrmation for fhe flow characteri tics have beert pt pared mong fh m, fhe followmg characteri tics shcil be presented selectively: resi tance profile wave elev tti m loccl resi tance velocitydi tribution limitmg stt tmlit pt ssme di tribution wake( tt the prop ller plane) Tcble 5 CPD Cod s md Characteristic to Be Cal tk ted or Mec tred Chsrscteristics H C P Viscous O O O Resishace Wave X X X Oversil X X X Protile X X X ElW~s~vtleon Locsl X X X Glob~ X X X Locsl resishace O X X Limiting stresm ice O O O Velocih distriLctioc O O O Presscre distriLctioc O O O Bocads y Isyer O O O Wske O O O _ _ b Tcble 5, fhe symbols of H

Read the entire page →

From page 933...

... , k md CFM represe t fomm factm md fi ictiot~l resi tance coefficient, respectively b c mputatimurl analy is, iscous resistance c tld be comidet d to be composed of two tt ss c mponents which are pemerldicular md t mgential to fhe ship hull, t sp ctively Whert twm tress coefficients perperldicular to md t mgential to fhe hull me denoted by Cv~ md CVF, vise ts resist mce coefhcie t c m be obtamed as follows: c~U = c>7 +c~ = 1(cy~ +c~ Kind ot Ship 300,000 TDW VLCC 1 70,000 TDW bulk mrrier 6,300 m3 LPG mrrier 4,200 TEU cochmer mrrler 5,000 tocce destroyer (withoct sppecdsges)

Read the entire page →

From page 934...

... Table 7 Resist mce Characteri tics Model Scale) Kind of Ship Test Condition Medhod C Mxto3 C Mxto3 CwxlO C Mxto3 Model test 3 841 0 042 3 883 LM =6 728 m E~1 3 662 300, 0 TDW :1 6 m/s STAR CD 3 174 3 800 Fn =0 142 FLllENT 4 034 SE FFL W 3 581 0 473 4 054 Model test 3 737 0 047 3 784 LM=7 551 m E~1 3 706 170,000 TDW 1 272 m/s bulkcarne R :097 10 STAR CD 3006 4312 Fn=0 147 FLllENT 2 918 SE FFL W 3 363 0 365 3 728 Model test 3 705 2 475 6 180 LM=6578m E~1 3 112 LFG car ~er ~t 995 m/s STAR CD 2 976 3 536 Fn =0 249 FLllENT 3 853 SE FFL W 3 364 3 339 6 703 Model test 3 038 0 24 3 277 LM=6 942 E~1 3 279 4,200 TEU 2 018 m/s co tamercarrier R ~ 40 10 STAR CD 2821 2997 Fn =0 239 FLllENT 3 338 SE FFL W 3 141 0 824 3 965 Model test 3 340 2 545 5 885 5,000 tom~e LM =5 0 m E~1 4 875 d~sp=nt :2 98t m/s STAR CD 2 952 3 230 (w6-ho t Fn =0 425 FLllENT 3 364 SE FFL W 3 362 2 384 5 746

Read the entire page →

From page 935...

... 4,200 TEU Co tamer Carrier Fig 3 Comparison of Profile Wave Elevati m Fig 4 shows th local resistance coeffcie 33 predicted by HtdRI cod Since it was not possible to be calculated by ocher codes, comparison could not be made How ver, it could be d duced Fiat fihe c mponent d e to pe pff~dicular to ship hull is dominent m th foreyard md oft pants while th component due to Fiction is domment m fihe middle Begun ~ .

Read the entire page →

From page 936...

... SHIPFLOW Fig. 5 Axial Velocity Contours of 30O,000 TDW VLCC at the Station 1 (x=0.95)

Read the entire page →

From page 937...

... SHIPFLOW Fig. 6 Limiting Streamlines for 6,300 m3 LPG Carrier

Read the entire page →

From page 938...

... SHIPFLOW Fig. 7 Pressure Contours on the Hull for 17O,OOO TDW Bulk Carrier

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From page 939...

... 9 and 10 show the axial velocity contours(wake) and velocity vectors on the propeller plane for 17O,OOO TDW bulk carrier and 4,2000 TEU container carrier.

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From page 940...

... FLUENT 0.~ r/R 0.0 Fig. 10 Axial Velocity Contours and Velocity Vectors on the Propeller Plane for 4,200 TEU Container Carrier CONCLUSIONS The flow characteristics around a ship hull were investigated through the numerical and experimental methods.

Read the entire page →

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Study on the Prediction of Flow Characteristics Around a Ship Hull Pages 927-940

Study on the Prediction of Flow Characteristics Around a Ship Hull
Pages 927-940