Sailing Performance and Maneuverability of a Traditional Ryukyuan Tribute Ship

Transcription

1 sia Navigation Conference 009 ailing Performance and Maneuverability of a Traditional Ryukyuan Tribute hip by Yutaka MUYM (Kanazawa Institute of Technology) Hikaru YGI (Tokai University ) Yutaka TERO (Tokai University )

2 INTRODUCTION Ryukyuan tribute ships were used for the trade between China and Ryukyu, south Japan, from 4 th to 9 th century. We revealed the sailing performance and maneuverability of a tribute ship. First, steady sailing performance of the ship was obtained using a velocity prediction program (VPP). Then, maneuverability of the ship was clarified by means of numerical simulation. The simulated results showed ship response to the steered rudder angle and ship trajectory.

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4 Beijing Fujian Naha Taiwan ailing route between China and Ryukyu 4

5 What is the Ryukyuan Tribute hip? 5

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10 Deck plan, and bow and stern plans of the model 0

11 Hull lines of the model

12 Principal dimensions of the tribute ship presumed from the model (in full scale size) Length over all: L O (m) 30.7 Length water line: L WL (m) 3. BeamMaximum: Bmax(m) 8.7 Beam water line: B WL (m) 8.5 Depth extreme: Dext (m) 6.8 draft extreme: dext (m) 3. L WL /B WL.74 B WL /dext.7 C B /(LwlBwld 0.4 Displacement: (m 3 ) 65 ail area: (m ) 70

13 Tank test model 3

14 Tank test in the circulating water channel 4

15 30 Resistance [KN] VB[kt] Estimated upright resistance of the tribute ship 5

16 6 Hydrodynamic coefficients of the hull D L V N N L D V K K L D V Y Y L D V X X B H H B H H B H H B H H,,, φ φ φ φ φ φ φ φφ N v N v N N K v K v K K Y v Y v Y Y X v X v X X vvv v H vvv v H vvv v H vvvv vv H ,,,

17 YH' XH',NH' [deg] Variation of hydrodynamic coefficients of hull with leeway angle (without rudder forces) 7

18 Hydrodynamic coefficients of the rudder X R K R C C Xδ Kδ sinα sinα R R sinδ, cosδ, Y R N R C C Yδ Nδ sinα R sinα R cosδ cosφ, cosδ cosφ, where, α R δ γ R tan v l u R ψ& R : Effective attack angle of the rudder R : Decreasing ratio of inflow angle l R : Distance between application point of the rudder force and C.G. of the ship 8

19 Rudder fastening ropes, and variation of rudder plate depth 9

20 R0 R R Even with keel depth Lower than keel by 5mm Lower than keel by 50mm (0.65m in full scale) (.30m in full scale) Difference of rudder depth for the oblique angle tests and rudder angle tests 0

21 XR' YR' NR' [deg] [deg] [deg] R0 R R Variation of hydrodynamic coefficients of rudder with rudder angle for the cases of R0, R and R

22 erodynamic coefficients of the sail 3 3,,, a a a a U N N U K K U Y Y U X X

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25 Performance of dual Chinese lug rig (hinshi-bo in Japanese) by wind tunnel 5test

26 .0 Wing and wing.5.0 Xs' Normal trim Xs', Ys', Ks', Ns' Ns' -.0 Ys', Ks' Wing and wing setting [deg] erodynamic coefficients of the dual lug rig for calculation of the tribute ship (for the case of starboard tack) 6

27 teady ailing Performance by Velocity Prediction Program (VPP) 7

28 8 Coordinate system and definition of forces and moments β β γ γ β γ ) sin( sin ) cos( T T T B T B T U U V U V U U

29 9 Equations for equilibrium sailing state 0, ) ( 0, ) ( 0 a B R H a B R H U Y LD V Y Y X U X LD V X X 0. ) ( 0, sin ) ( 3 3 a B R H a B R H U N D L V N N GM U K LD V K K φ Unknown variables obtained by Newton-Raphson method (Velocity Prediction Program VPP) ship velocity : V B leeway angle : heel angle : rudder angle :

30 True wind speed VB [knot] T 30 [deg] Rudder depth: R [deg] U0[m/s] U 8[m/s] U 6[m/s] VB VB[knot] T [deg] teady sailing performance at the true wind speeds of U T 6, 8 and 0m/s with the rudder depth condition R 30

31 Rudder depth VB [knot] T 30 [deg] [deg] U 8[m/s] R0 R R VB VB[knot] T [deg] ailing performance variation with the rudder depth condition 3 at the true wind speed U T 8m/s

32 Numerical imulation of Wearing Maneuver 3

33 33 Equations of motion for maneuver urge: 0 ) ( ) sin cos ( ) ( X U X D L V X X v X v m m m u m m a B R H v z y x ψ ψ φ φ ψ & & & & m mass m x, m y, m z added mass u, v velocity components along x and y-axis X 0 resistance at upright condition

34 34 Roll: Yaw: way: a B R H y z x z y U Y L D V Y Y Y v m m u m m v m m m ) ( cos )sin ( ) ( ) sin cos ( ψ φ φ φ ψ φ φ ψ & & & & & { } φ ψ φ φ φ sin ) ( cos sin ) ( ) ( ) ( 3 GM U K L D V K K J I J I J I a B R H zz zz yy yy xx xx & && { } { }. ) ( cos sin ) ( ) ( )cos ( )sin ( 3 a B R H zz zz yy yy zz zz yy yy U N D L V N N N J I J I J I J I ψ ψφ φ φ ψ φ φ ψ & & & && &

35 U T 8m/s Port tack tarboard tack (a) R (-60) 40 (-0) (b) R (-60) 40 (-0) imulated time histories of sailing state parameters for the cases of R0 and R rudder depth conditions 35

36 50m Wind UT 8m/s tart of wearing maneuver R0 R R imulated ship trajectories at wearing maneuver for the cases of R0, R and R rudder depth conditions 36

37 Conclusions ailing performance and maneuverability of a tribute ship were studied by means of VPP and numerical simulation. The actual closest sailing angle to the wind of this ship was assumed to be around 70 degrees, and the fastest velocity was almost 30% of the true wind speeds. The turning radius was estimated about 80m, and the adequate rudder depth was suggested. These results will provide useful suggestions for the maneuverability and sailing technique of the tribute ships, which are not mentioned in the old documents or only 37 supposed from the old pictures.

38 Thank you for your kind attention. 38

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42 X Y Z Euler-Lamb equations of motion b K M N b b b b b ( m m ) u& x ( m my ) rv ( m mz ) qw ( m m ) v& y ( m mz ) pw ( m mx ) ru ( m m ) w& z ( m mx ) qu ( m my ) pv ( I xx J ) p& xx ( my mz ) wv {( I yy J yy ) ( I zz J zz )} ( I yy J yy ) q& ( mz mx ) uw {( I zz J zz ) ( I xx J xx )} ( I J ) r& ( m m ) uv ( I J ) ( I J ) zz zz x y qr rp { }pq xx xx yy yy x y z b b b cosφ sinφ 0 x sinφ y cosφ z Equations of motion expressed in the horizontal body axes system 4

43 ngular velocity terms X dded masses and added moments of inertia π m D C ( x) dx where, J m J vr y zz z yy m ( C ) m π Y r k 4 N r k 0. 54k y L π x D C y L π B Cz 8 L π x B C 8 L y ( x) ( x) z dx ( x) dx dx where, k: spect ratio of projected area of under water part of the hull ( C ) 3C C y ( C C ) 3 ( x) where, ( C ) 3C C z ( C C ) 3 ( x)

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