Propulsion Optimization Diagrams for Fishing Vessels

8/6/2019 Propulsion Optimization Diagrams for Fishing Vessels

1/14

Proceedings of the ffh International Marine Design Conference, 5-8 May 2003, Athens, Greece

PROPULSION OPTIMIZATION DIAGRAMS FOR FISHING VESSELST.A. LOUKAKIS 1, G.J.GRIGOROPOULOS2 and S. PEPPA3

National Technical University of Athens, Laboratory for Ship and Marine Hydrodynamics, Greece'Ioukakisrgccntral.ntua.gr, [email protected], [email protected]

ABSTRACTPropulsion optimization diagrams have been developed for a family of fishing vessels. Thediagrams can be of use for a wider family of traditional vessels and the method can be applied toother vessel families as e.g. fast modem monohulls.1. IntroductionPreliminary but reliable and easy to obtain estimates of the propulsion characteristics in shipdesign are hard to come by. This is particularly true for new designs pushing the frontiers ofpropulsion hydrodynamics, as e.g. is the case with modem fast passenger and car-passengerships. Even for conventional vessels, few attempts are known (e.g.[l]) which, on the basis of thepropulsion characteristics of existing ships, can predict the propulsion requirements of a new butconventional design.However, there can be exemptions to this rule for special cases i.e. for families at vessels, whichpossess "similar" hydrodynamic characteristics, where the term refers to similarities in the hullform and the propulsion used. The family of vessels to be addressed in this paper is the large oneof fishing vessels of traditional design, still extensively used in Greece and which are similar tomany fishing vessels in the rest of the Mediterranean Sea. Moreover, vessels with the same typeof hull form are used as pleasure and tourist craft, as well as small payload cargo vessels forremote island and coastal destinations. These simple vessels use mostly common propellers inconjunction with rather large Diesel engines, which often drive the sailing vessel hull forms ofyesteryear to excessive and uneconomical speeds in the range Fn =0.35 to 0.40.To proceed with the development of propulsion design diagrams for this type of vessel, one hasto know their resistance characteristics, their propeller - hull interaction coefficients and thecharacteristics of their propellers. The last of these requirements is the easiest to meet because thewell-known Wageningen B-Series Propellers are well suited to represent the commonly availablepropellers for fishing vessels and their characteristics exist in analytical terms [2]. The first tworequirements are also met, since the resistance and propulsion characteristics of fishing vesselsand similar hull forms of traditional design have been studied experimentally in the Towing Tankof the Laboratory for Ship &Marine Hydrodynamics ofNTUA for the last fifteen years. Thus, allprerequisites exist for the creation of new propulsion optimization diagrams.

123
mailto:[email protected],mailto:[email protected]:[email protected]:[email protected],


2/14

P ro ce ed in gs o f th e 8 'h I nte rn atio na l Ma rin e De sig n Co nf er en ce , 5-8 May 20 03, A th ens, G ree ce

2. Resistance & Propulsion Characteristics of Fishing VesselsThirty years ago, Antoniou [3] investigated the characteristics and the resistance performance oftraditional Greek hull forms used mostly for fishing vessels. Due to the lack of experimentalresults for the selected representative hull forms and the absence of a towing tank in Greece at thetime, he used model scale data of similar hull forms found in international publications to derivean empirical formula for the estimation of their calm water resistance, aiming at the developmentof more efficient and economical types.Fifteen years later Ganos & Loukakis [4] presented experimental results for the trechantiri-typevessels, aiming at the development of a systematic series using three models with LIB values of2.5, 3.0 and 3.6, tested at various values of displacement and trim. Finally, during the last tenyears, considerable effort was put in the Laboratory for Ship and Marine Hydrodynamics toinvestigate experimentally the resistance and propulsion characteristics of the more representativehull forms of traditional Greek vessels. This attempt, which encompasses the construction andtesting for resistance and propulsion of seven models, has been partly supported by the GeneralSecretariat for Research and Technology and by numerous last year students in the context oftheir diploma thesis .. The first two of the authors supervised this time-consuming work whileDoctoral Candidate Ms A. Prifti supported some of the resistance tests and a large part of the self-propulsion tests [5].The three of the original trechantiri-type models work were appropriately modified to complywith the constraints of a systematic series where only the LoAlBoA ratio is varied. In addition,models for perama, karavoskaro, varkalas and liberty - type vessels were designed, constructedand tested. The present work is based only on the resistance results of the trechantiri - typemodels. However, as it will be demonstrated, the propulsion design diagrams can also be usefulfor the other types of traditional vessels, except karavoskaro.Although tests have been carried out at three trimming angles, i.e. 0.0, 1.5 and 3.0, it wasdecided to use only the results for a trim of 1.5, which is usual for this kind of vessels, withoutloss of generality.The body plan of the trechantiri-type vessels is shown on Fig.l and the respective total resistancecoefficients CTL (defined as CTL = RT . ~ ) when trimmed by 1.5 to the stern, are shown in/). FnFig. 2. The nine CTL curves in Fig. 2 pertain toLWL/V

I/3= 4.2, 4.0 and 3.8 for LIB = 2.5,LWLV 11 3= 4.5,4.2 and 4.0 for LIB = 3.0 and LWL/V1/ 3= 4.7,4.5 and 4.2 for LIB = 3.6. (The CTLvalues throughout the paper are based on the model scale results. In this way the very smalldependence of CTL on scale has been ignored).By inspecting Fig. 2 in the speed range of current practice (Fn= 0.25 to 0.40), one can concludethat the values of CTL can be approximated, with reasonable accuracy, by a single curveapplicable to all LONBOAratios and LwJVI/3 values. Similar results are derived for the otherthree types of traditional boats, i.e. perama, varkalas and liberty, as it is shown in Fig. 3 for thetrim angle of 1.5 by stern and three 1/V1I3value per type as follows: Perama: LWL/V l/3 = 4.8, 4.5

124


3/14

P roc eed ings of th e {fh I nte rn atio na l Ma rin e De sig n Co nf er en ce , 5-8 M ay 2003, A th ens, G reece

and 4.2 for LIB=3.2, Varkalas: LWL/\71 1 3= 4.6, 4.5 and 4.4 for LIB=3.3, Liberty: LWL/VII3 = 4.8,4.7 and 4.6 for LIB=3.4. The CTL values for the trechantiri-type vessels are superimposed on thisFigure.On the basis of the self-propulsion tests it was concluded that single values can be used for thepropulsive performance coefficients i.e. the thrust deduction factor t, the wake fraction w and therelative rotative efficiency ll R in the speed range of Froude numbers 0.25 to 0.40. These averagevalues are shown in Table 1.It should be noted here that the unusually large values for t, w and l lR for these vessels of low Cpvalues, are due to the bad stern flow at high Fn and to the existence of a very thick skeg in frontof the propeller.

Table 1: Representative values of propulsive performance factorsLIB 2.5 3.0 3.6

Thrust deduction factor (t) 0.38 0.38 0.38Wake fraction (w) 0.35 0.33 0.31ReI rotative efficiency ( l 1 R ) 1.10 1.10 1.10

I I

I j __.J..---"

(a) LOAlBoA=2.50 (b) LOAlBoA=3.00

Fig. 1:The lines-plans of the three trechantiri-type models used in the tests.

(c) LOAIBOA3.60

125


4/14

P roc ee ding s o f th e 8 'h In te rn atio na l M ar in e D es ig n C on fe re nc e, 5-8May 2 003 , A th ens, G ree ce

0.60 -'-r=====~----;------;------'

0.50LIB = 2.5LIB = 3.0LIB = 3.6 1/3Lw11' 1+ LW':z1 ~3V LW':3' 1/ 3

-----1 t- - - - - - -

TRECHANTIRITrim=l.S deg by stern

0.40 - - --~ - - - - - - ~

j:!o 0.30

0.20

0.10

0.10 0.20 0.30Fr 0.40 0.50

Fig. 2: Modified total resistance coefficients CTL of trechantiri-type models0.60 -,-;============::---;----,------,

..JI-o 0.30

0.50

FISHING VESSELSTrim=l.S deg by stemTrechanti ri LIB = 2.5Trechantiri LIB = 3.0Trechantiri LIB = 3.6Perama LIB = 3.2Varkalas LIB = 3.3

-1- - - - - - t- - - - - - -

0.40 ~ - - - - - - ~ - - -- - -Liberty LIB = 3.4 Lw~ 1 11/ 3+ Lw~1 21/ 3

V Lwli 31/3 -,------

0.20 _1-_____ .J

0.10 I - - - - - -

0.10 0.20 0.30Fr 0.40 0.50

Fig. 3: Total resistance coefficients CTL of all types models.

126


5/14

Proceedings of the ffh International Marine Design Conference, 5-8May 2003, Athens, Greece

3. Optimization Diagrams for Preliminary Propeller DesignA new form of optimization diagrams for preliminary propeller design was presented severalyears ago by Loukakis & Gelegenis [6], using the analytical form of the Wageningen B-Series.The new diagrams could be used to solve, in a user - friendly manner, both the problem ofoptimum revolutions and the problem of optimum diameter. However, as is mostly the case inpropeller design and especially for smaller vessels, the largest propeller diameter to fit the stem isused for fishing vessels and thus the propeller revolutions optimization problem will be the onlyone to be shortly presented here.When using systematic series for propeller design, there are ten problem variables: UE, PID, J, Re,n, D, SHP, T, V A and TP; excluding the number of blades z, which is to be determined fromvibration considerations. It is assumed that the propeller - hull interaction factors w, t and 11Randthe shafting efficiency 11sare known.These ten variables are implicitly related by the following six relations:FI : KT(UE, PID,J,Re) - T /(pn2D4)F2: KQ (aE, PID, J,Re) - SHP TJ R 11s/ (21tpn3D5) = 0F 3 : J - V A / (nD) = 0F4 :T-FT(VA)=OF 5 : Re - F R (aE,J,n,D, V A ) = 0

where:F I and F2 are the analytically known open water propeller characteristics, FT(VA ) =Fs ( VA ) + TPrepresents the required thrust necessary to overcome the hull resistance, Fs, while providing abollard pull, towing, or trawling requirement TP, FR is the expression of the Reynolds numberand Fe expresses some practical cavitation criterion (e.g. Burill's).Thus, the ten problem variables are connected by six relations and for the solution of particularoptimization problem one has first to specify three of the variables and then obtain an additionalrelation of the basis of the corresponding optimization requirement. However, if VA and TP areprescribed then T is directly obtained from relation F4 and the prescription of one additionalvariable is necessary for optimization.For usual preliminary propeller design relations Fs and F6 can be dropped from the formulation,together with variables Re and aE. This is so because the Re dependence of the analytical KT, KQforms is both of mediocre quality and does not take into account propeller blade roughness andone can pre-select an adequate aE and then test the final result for cavitation. In this respect it iswell known that fishing vessel propellers with relatively low UE values do not suffer fromcavitation and that relatively large UE values improve propulsion performance in waves. We arethus left with eight problem variables connected by four relations.

127


6/14

P roceedings o f th e 8 'h I nt er na tio na l Ma rin e Des ig n Conf er en ce , 5-8 May 200 3, A th ens, G reece

The most appropriate problem in preliminary propeller design for the free running case (whenTP=O) is: when the ship speed is not specified, the largest possible propeller diameter is used andone tries to decide which from a number of existing engines (SHP) should be selected. Obviouslythe size of the engines under consideration is expected to result in a ship speed near or above atarget speed. Hence SHP and D are specified and the optimization relation is provided by therequirement:

dT / dn= 0which maximizes the ship speed.The corresponding form of the optimization relation is shown in [6] to be:

(2)

8KT (J 8KQ _ 3K ) + 8KQ (2K _ J 8KT) = 08(PID) 8J Q 8(PID) T 8J (3)Relation (3) is shown in [6] that is all that is necessary to solve any propeller revolutionoptimization problem, including towing with specified pull TP or bollard pull (J=O) problems.More specifically, with Re = 2x 106 and specified values for UE & z, the system of the fiverelations FJ, F2, F3, F4 and (3), in which the eight variables P, D, J, n, SHP, T, V A & TP appear,can be solved numerically when values are assigned to three at the above variables, yielding theoptimum solution. In this way, "optimum RPM" diagrams can be produced. The diagrams areplotted on (PID) vs. (n-D) axes and consist of families of curves with constant values for V A ,SHPID2 and TID2 (see e.g. Fig. 4). All propeller revolution optimization problems can be readilysolved on these diagrams.The procedure to be followed for the solution of the most common problems is: When VA , F, (VA ) and TP are prescribed, then T is also known. Additional prescription ofD determines the value of T1 D 2 and the solution is found at the intersection of the above curveand the curve VA =const. When V A , SHP and D are prescribed, the same procedure is used with SHPID2. The curve

T 1 D 2, which passes from the solution point, provides the maximum thrust Tmaxfrom which,using the relation Tmax=Fs( V A )+ TP, the maximum trawling, towing or bollard pull requirementTPmaxcan be determined. The hull resistance Fs( V A ) is assumed to be known for the towingcondition or it can be neglected for low values of VA. When SHP and D are prescribed, the thrust requirement curve T1 D 2 =(Fs( V A )+ TP) / D2 isdrawn on the diagram (the towing requirement TP-zero for the free running case-must bespecified) and the solution is found at the intersection of this curve with the known curveSHPID2.The diagrams pertain to specific values for 1 1R and 1 1 s and in the present application 1 1R =1.1 and1 1 s = 0.98 have been used.

128


7/14

P ro ceed ing s o f th e tfh I nte rn ati on al Ma rin e De si gn Conf er en ce , 5-8 M ay 2003, Athens, G reece

4. Propulsion Optimization DiagramsIf the propeller diameter D is taken as having a constant DIL value, which is the common practicefor traditional vessels, then the test results for a model with a particular LIB value, tested at aspecific value of LWL/V1/3nd with a specified trim; can be used to obtain T/D2 = F, 01A)curvesfor any vessel length, if the values of w and t are known, constant or functions of VAand thevessel is free running, i.e. TP=O. In this manner the resistance results of paragraph 2, inconjunction with the average constant values for w, t & T]R obtained from the self-propulsionexperiments, can be used to produce the propulsion optimization diagrams shown in Figs. 4, 5&6 .The diagrams were produced using values of: DIL=1I15 and w, t & T]R as specified in Table 1 andpertain to: LoA=8, 12, 16, 20, 24m for LIB = 2.5 (LWL/V1I 3= 3.8, 4.0 and 4.2), LIB = 3.0(LWL/V1/3= 4.0,4.2 and 4.5) and LIB = 3.6 (LWL/V1/3= 4.2, 4.5 & 4.7), where LOA& BOAare themaximum overall values, LWLthe length at the waterline and V the volume of displacement under .this waterline.The use of the diagrams is obvious. With prescribed LOA,LIB & LWL/V1/3values, one can byinterpolation determine either the necessary SHP for a desired speed Vs = VA I (l-w) or the speedthat can be obtained if an engine with a known value of SHP is used. In both cases, thecorresponding value of the ordinate (RPMD), yields the required RPM (since D is known) forthis optimum solution of the propulsion problem and hence the required gearbox. The value PIDof the abscissa gives the value of the optimum propeller pitch P.The propulsion optimization diagrams can be of additional use in the case of vessels working attwo operating speeds, as e.g. the trawling vessels which tow fishnets at low speeds. In this casethe resistance of the hull form Fs0' A)must be known at the low (2 + 4 knots) trawling speedrange or it can be neglected in front of the required large TP force. Then T & T1 D 2 are known andthe solution can be found at the intersection of the above curve and the curve of the prescribedtrawling or towing speed. This second solution yields a different (lower) optimum propeller pitch,different optimum propeller revolutions and different SHP requirements. It is then up to the navalarchitect to take into account additional requirements of the owner -and select a compromise (P,SHP, RPM) solution, which will be satisfactory at both operating speeds but non - optimum ineither case.Example: Find the optimum solution for a trechantiri type vessel with LoA=20 m, D=1.33,LIB=3.0 and LWL/VI/3=4.5 with SHP=400 PS at (i) service speed ofVs=10.2 Kn and (ii) trawlingspeed of VTr=4Kn.From the propulsion optimization diagram (Fig. 6) the solution of the propulsion problem forboth cases is as follows: (i) P/D=0.749 and (RPMD)=635.7 from which we obtain RPM=478, (ii)PID=0.634 and RPM=493. Interpolating the optimum solutions (i) and (ii), an intermediate PIDratio should be selected with satisfactory (non-optimum) performance in both service conditions.Finally, by inspecting Fig. 3, an additional use of the propulsion optimization diagrams isdeducted. The simultaneous plotting of 18 e T L vs. Fn curves (six vessels at three displacements

129


8/14

P roce edings of th e gh I nte rn atio na l Ma rin e De sig n Co nf er en ce , 5-8May 2 00 3, A th en s, G re ec e

each) reveal the remarkable fact that for Fn=O.4, CTL has a practically constant value of 0.215.Thus one can select an engine, a propeller and a gearbox for optimum operation at Fn=O.4 for anytype of traditional vessel with minimum information as follows:With the knowledge of only LOA(LWLis taken as 0.95 LOAfor all cases with good accuracy andD= LOA/15)and A , the required thrust T (t is assumed to be known) is given by

TID2 =0.215(0.4)2152(1 - tr!M~A =12.484D.. IL~A[mt lm2]for t=0.38. Then, the solution of the propeller revolution optimization problem can be found atthe intersection of the TID2 =f(LOA,!1) curve and the

!VA= (1- w) x 0.4 x (g x 0.95 x LOA)2O.SlY! = l.S89LoA[kn]which corresponds to Vs = 2.372LoA [kn], for w=0.33 taken as an average value from Table 1.In this manner, an overall propulsion optimization diagram of general use can be constructed asshown in Fig. 7, from where one can by interpolation select an optimum (SHP, P, gearbox ratio)combination for any traditional vessel of known length and displacement.The selection of Fn=O.4 as the design speed for this type of vessels, although extremely high fornormal displacement type ships, is common practice for the small traditional vessels andespecially the fishing vessels by order of their skippers.5. ConclusionPropulsion optimization diagrams can be constructed for families of vessels with similar hullforms and propulsion characteristics, allowing preliminary (which in most cases for small vesselsis actually final) propulsion design, based on the propeller optimization diagrams developed byLoukakis & Gelegenis [6]. The next application of the novel diagrams will address the moreinteresting professionally problem of the propulsion of fast craft in the semi-planing speedregime, using the high quality hull forms developed at N.T.U.A. and recently presented byGrigoropoulos & Loukakis [7] at the annual 2001 SNAME meeting.List of Symbols

L,LoALIBBOA,BL W LV '!1PVsVAa EDJKT

overall lengththe ratio of the overall length to the maximum breadthmaximum breadthwaterline lengthvolume of displacementdisplacementwater densityship speedspeed of advanceexpanded area ratiodiameter of propelleradvance coefficientthrust coefficient

130


9/14

P roceed ing s o f th e [f h I nte rn atio na l Ma rin e Des ig n Conf er en ce , 5-8 May 2 00 3, A th ens, G reece

K QRTPTTPzn,rpm,RPMSHPFn = V / f i L W L

RT 1CTL=---!1 Fn2L IV 1/ 3W LtW

1 1 R1 1 s

torque coefficienttotal resistancepitch of propellerthrust of propellerbollard pull, towing of trawling requirementnumber of bladespropeller revolutionsshaft horsepowerFroude number, Frtotal resistance coefficientFroude length constant, Mthrust deduction factorwake fractionrelative rotative efficiencyshaft transmission efficiency

6. AcknowledgementsThe authors are indebted to Mr. G. Katsaounis and Dr. K. Belibassakis who contributed to thecomputational analysis of the results and the derivation of the plots.7. References1. Harvald, Sv. Aa., "Prediction of Power of Ships", Department of Ocean Engineering, TheTechnical University of Denmark, Lyngby, 1977.2. Oosterveld, M We. and van Oossanen.P; "Further Computer-Analyzed Data of theWageningen B-Screw Series", International Shipbuilding Progress, Vol. 22, No.251, July 1975,pp.251-262.3. Antoniou, A., "Research on the Naval Data of the Greek Type Vessels", NTUA PhD thesis,Athens, March 1969.4. Ganos, G. and Loukakis, T. "Resistance Characteristics of the Trechantiri Type Boat", 3rdIntI. Congress on Marine Technology, Athens, 1984.5. Grigoropoulos, G. and Prifti, A. "Resistance Characteristics of the Traditional Greek FishingVessels", 5th IntI. Symposium on Technics and Technology in Fishing vessels, Ancona, Italy, May1995.6. Loukakis, T. and Gelegenis, G.J. "A New Form of Optimization Diagrams for PreliminaryPropeller Design", RINA, London, April 1988.7. Grigoropoulos, G. and Loukakis, T. "Resistance and Seakeeping Characteristics of aSystematic Series in the Pre-planing Condition", Part I, SNAME Annual Meeting, Boston, MA,25-28 September 2002

131


10/14

o~ " ~ ~ ~ ' ~ " " ' ~ ~ ' ~ ' ~ " " ~ " ~ / ~ ' ~ " " ~ ~ J . ~ " " ~ ' ~ ~ ~ r ~ ~ ~ l..~ o "! ~~ /js# I;IJ.ttJIT< ;~ jrl ~..Ii If)l 0 0 1 I . ! . ~ ~ / ~ I . / . " ' f l - I . / . j ' I . '. . . 1 . .] . 1 . . . . 1 . .. ' / '. I O O ~ f I . . I : '(f) C') C') - 0. e n 1 -; :1 - . . I .... ". ( '.. : : J '" I..~;_>;_5 ; ; BII' IIIi 1...._ , I D o t 1 1: ! l l ~ ~ ~ g a : 'bj'~i}ftIJIII~IIJoflll~ . ~ f f i~ . . ! . ! . 1 / l I . l j . . . .' t - I I . } 4 . ~ l t l

! .. .. I ...//11 Ir- E r I I ~ J . I + 1!~/ ~ ) ~ . ! . : . ! / ; z ~ J . ) . l ! J . t ! . } . ; ~ r . I . ; t r . . .I L j ~ . : . i l l jv I l :~ / ~..... / ...~. !.1 Y 0 1 1 1 1 1~.// ...4../ll7 . l l : ~ I I : ~ e I 1; / .I.~. . / ;. ..:;. I 0 ) . / - ; " : ~ , . '~ . . ' 1 . . ~ . . . 1 . . \2 /......... I . . . . . . r ." ." .... .....O \~.........I..8f . .} . . . .I . ( . . . ! I..~ . r , ' ! 1 . 4 r l . J . . I . l O i [. . . . . . \. / . . . / z : ; J - . ! J . ; / -;!li'~rll! .. (0 ' / \~ 7 ...7 : : : : : 7 . :~~.?/1./...!f.. . f , I - J ~ : ; I . 8 ;///ttll/l,!ttjI I o ~ / 1 1: : : : / ? : , ; f , ' ; . f . . Z : : . : . ~ / !:.j/ ./ i l : . : . .; : . : l i l ~ / ( : ~ . i : '~ /... ~4. / ! . . . . . I , , , . . . . ;'_ 'j ... ;. ~ E I.... II~ ~"""].""" ::::); ; , _ : : : : : ! .r.:/":.:::." A . : / ! I f f : '# : ' : , ; : : :~ : : : : : : ; ': : : :o : ~ ~ : : : :1 : : : : : : E ../, /. ...8 ~ 7 j...... ~:itl,,'l.t' iljJ...: ...~t. Ic /. . .r. Ltf. ... ........').'::~'...Jl......"... ~ : . , j - . fit: 4 . " . / . . . . )~ . (. . . . . . ~ 7 . f A f I J . t l l j . i ~ ~ / . 11 1 / / , y . y . r t " ; / . . ' !' I.. I I lF-]. ' t l : : \ ' 1 1m r L;.tt ...~, ,Tf~ l e " ~ I~..7;it7../lt/~~~,.lT ...r ~ 1 1~ 7 . . . . : . ~ : v 7! i~' ..,.~i,'i.'f ~ ~ I I l . o E . 1 . : : : 1IU :: . . / . _ J . . . .Fill.11 "1'''/ /.. -;\- .1 ~ /..:;;o.t ....7 . . . . . : I / ~ T J l ' i l l ! l i . .:~i. I : : : I o ~ J - o - 11-./ ..?~6:t.......'II/111" .. li/... " '/" .09[.~ '..< . .. . /.:".~/.1. : ; J . .~: l i . ' . 1 ' . Ii' j' " ; 1 - ' I/.. ...0 /, lil(~1/ ; o s ./............... /~,IJ,o;,jr,.r /. .. ./ L e t . . . . / , ~I'(i;, r 0 . I. . . . ; / 7 , . . . . . . . . . - : / l i ! . ~ ~ ~ / L / l A . l l . . ! / .,./ .I4...[(/" '(// . / : . 1 . . . . . . . . . . . . 0 .. I.. .... I ~. 111.1llrJII/ I "

P ro ceed ing s o f th e lf h In te rn atio na l Ma rin e D es ig n C onf er en ce , 5-8 May 20 03 , A th en s, G reece

100)o0)

oO J 10o r - - . .O ld 0

10(0o(0

o1 . 0C Oo

r - - . .o

132

oo0)

ooC O

oor - - . .

oo(0

oo10

oov

ooLOC')10o


11/14

Proceedings of the s th International Marine Design Conference, 5-8 May 2003, Athens, Greece

133

oo(J)

ooC O

oo, . . . . .

oo(0

oo1 .O

oo~

ool.O('I)1 .Oo

..I/')~

. . . . .r ; . ; .


12/14

P ro ce ed in gs o f th e B " h'In te rn atio na l M arin e D esig n C on fe ren ce , 5-8 May 2 00 3, A th en s, G re ec e

1O0)o

0)a 1Oc oac o 1Oa t - - .

aId 0t - - .o 1OC Do

134

C Do

aac o

aat - - .

aa1. 0

aav

aa1 O C ' >1Oa


13/14

P roc ee ding s of th e E J " h In te rn atio na l M ar in e D es ig n C on fe re nc e, 5-8M ay 2003, A th ens, G reece

aId135


14/14

P ro ceed in gs o f th e 8 'h I nte rn atio na l Ma rin e De sig n Conf er en ce , 5-8May 2 00 3, A th en s, G reece

0.60TRECHANTIRITrim=1.5 deg by stern

LIB = 2.50.50 LIB = 3. 0 -t - - - - - - t-

UB = 3.6 1/ 3Lwl1l 1+ Lwl;zl ~3 .. ! ~ .40 - - - - - -V Lw':31 1/ 3...II-0 0.30

0.10 0.20 0.30Fr

0.40 0.50

Fig. 2: Modified total resistance coefficients CTL oftrechantiri-type models0.60 i::=======::::---;---ji--;--,-----,

0.40

Trechantiri LIB = 2.5Trechanti ri LIB = 3. 0Trechanti ri LIB = 3.6Perama LIB = 3.2Varkalas LIB = 3.3

-t - - - - - - t-

...II-o 0.30

FISHING VESSELSTr im=1.5 deg by stem

0.50

. . ! - - - - - - ~Liberty LIB =3.4 Lw~ 1 11/ 3+ Lw':2l 2 11 3V Lwii 3 1/ 3

0.20

0.10

0.10 0.20 0.30Fr

0.40 0.50

Fig. 3: Total resistance coefficients CTL of all types models.

126

Propulsion Optimization Diagrams for Fishing Vessels

Documents

Transcript of Propulsion Optimization Diagrams for Fishing Vessels