109
---r
A Study on "Heaving tó" by Alcira IwalAbsfrat
Orte of the ptirpose of "Heaviñg to" is to keep a good stability by decreasing the shipping of waters on deck and shocks of waves. And the shipping of waters
under adverse sea will be given by
ì=Çt D.B.bc.dt
(1);J=o
here
V: volume of shipping of waters for one vertica1mnotion
D : vertical displacément of upper deck part on bow beliw the sea sur-face
B : ship's breadth
bc : effèctive ship's breadth coefficient T.: wave period
- And theti the term D of equatiòn(1) Elepends n thea relation betwéen ship's speed and wave nati.ue that is decided by the reÏativè niotiòn hip and wave So we can find the moderate èpee frórn the viewroint Of ship-handing in a high sea, by the application of this equation (1).
Fig 7. in this paper shows the results of the qüantitative axa1ysis by this
ecuation on T. S. Shioji-Maru, as an exàm pie.
in this case we can undettand
that it
is necessary to mind the effects of wth?e iength, wave steppness and ship's speed reduction òn decision of ship's speed in "Heaving to".iac
3.1 q)i .3. 4hQJ
5. t1-Ut,
Ì1 <((
5t-D Heave to
1)QJt.
L4
.o-t. LFO
Hèave to 2. 5Th:-r,
?r
WZ+-frW7
COS (cogt-6w) .. . (1)..
Z, 'P
; . . S..
...
.. . . CO6,wB:
s
--
+2h +v9s=fs(S) (w8t&) (2) 2:s(t)=E8.,.rm
(Sill)(te)
(3)
s:
(*'± ,
ET2)
2h8:
rm
:(jo/2)
1 :4*
--Green Wàter
F1oog
-1-
2: 2:1.
D=rm COS (7+w8i) Wm COS
(o,8t) +1F
D:
7-:
"2:
,
-LfL
ìtr
Lt.ftO2: Lt*
1--vÇ
t D.B.bc.dt (5)bc:
V: J(
3.*I].
Q) 251. 7OTon Diesel 148.99' 3801P 380 R.P.M. 3.1 JQ ft a.Lit.
qpj , ,±:ff2
ft.
Figi
1n<
cï
I1 e'Jl 4,200gr.cm2 1O,OOOr.p.m 20° 40° ':i
LIJ2OV.D.0 5WT 2°».'5°/min 2k 28V.D.0 28V.D.0 O.5A 14WLT 4.5kg*L L-ft.
Vt.
Loa 32. 65m Cp 0.586 Lpp 29.00" Cb 0.530 B 6.20n' Cw 0.754 D3.45'
11.52 d 2.46e 10.00b. i;g
L. sine
LAg cEDJt
t Z o V q 'O'c*.oCb3.2 o(.° (&4 * )
Lc
Fig 2c)j
ìt0
a. .. -¿ ±'CÊ4tZ. Fig 3
45°&hi, .ftn
-'Zi-r
"A". gyro-motion113--i
9j5 lrn/23rn6.19m/s 273 2.9e 0.81° 78°. 7.02°. 079j5
2 6 '/ 'i 3.27 3.5 1.09 if f' 'i 1.55 3 2 '/ // 3.40. 3.6 2.20 if // . 3.13 4 0-- Ñ i' 3.80 3.8 1.64 t' // i' . 2.34 5 8 2/28 - ß.83 4.09 3.6 4.69 12.8 11.5 0.99.. 4.08 6 - 4 'i - 4.f5 4.05 6.51 'i - 1/ 5.66 7 0 // 4.'20 4.20. 5.05 t' t' . i' 4.39: X: 1 o 0 0cO plot
OZP
4.0 o o oÌiW L±o Base
20E L.
o o : T: aa4MJ L-C li ;.
D L©
i. :2. VC ,'uic.) SO 6.i (s.)
F1g3 F1g4 b. Fig 4 (V) (VL)ÙW (q'm/zm)
Lft(IiJLft).
it Fig 6 Fig7 ¿'± bc=O.8
*(5)-CÍ5ft
(X/L)r'
-- LcW
L-ft 4. LQ)4J*Ui
:iLt
7J 2D I0.0(i)
o*
x/L=1.5011LL
(ii) *D*
b x/L=1.5o.-
115-3M 4m/sec, 3!. /L=1.25 3.5m/sec b,
*5iilt
i-.
(iii) X/L=1. 5O-2.5OLftç
* L
Cb x/L1.25
Heave to()
, 1.5 54J &t.
(6)
VL==i.50 ÔLLcJfto
LU*() Lee shore
i .%-o steppness (ìft)
1/107k7
CtL
c Heave to
j---t,
LO
Heave to . Heave to jIJo
5.ü
I-
veolJ
Heave toorL-c,
*
L ' <*±LCL C -
l- C Heave toPJf LC.
bM. t. Denis : On Sustained Sea Speed. S.NAM.E; 1951.
M St Denis and W J Pierson On the Motion of Ships in Confused Sea S N A M E 1953
WP 1955
W. Möckel Über die Scefähigkeit von Fisckampfen. Schiff und Hafen 1953. T.H. Hàveloôk Notes on the thcory of Heaving and Pitching. T.I.N.A. 1945.
: No 58(1 1956.