Method of ship ice resistance model experiment based on non-refrigerated model ice

Patent metadata

Field	Value
Publication number	US-11768126-B2
Application number	US-201917044773-A
Country	US
Kind code	B2
Filing date	Aug 9, 2019
Priority date	Jan 5, 2019
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

The present disclosure discloses a method of ship ice resistance model experiment based on non-refrigerated model ice, including the following steps: determining the overall length L 1 , breadth B and scale ratio λ of a selected ship model; determining the size A 1 of an experimental area for placing broken ice in the ship ice resistance model experiment; determining the characteristic length of model ice; determining the quantitative proportion of the model ice for each size under the target coverage ratio c of the model; obtaining the number of the model ice for each size under the target coverage ratio according to the quantitative proportion of the model ice for each size under the target coverage ratio c and the total area A 2 of the model ice; determining the geometrical shape and parameters of each size under the target coverage ratio c of the model ice. The present disclosure solves the problems of poor economy and poor operability in a freezing model ice experiment of an ice basin, and provides a design method for carrying out a ship ice resistance model experiment in a towing tank.

First claim

The invention claimed is:

1. A method of ship ice resistance model experiment based on non-refrigerated model ice, comprising the following steps:
S 1 . determining an overall length L 1 , a breadth B, and a scale ratio λ of a selected ship model;
determining a size A 1 of an experimental area for placing broken ice in the ship ice resistance model experiment: according to the overall length L 1 and the breadth B of the selected ship model, determining the minimum size of the experimental area, further determining the size of the experimental area:
L 2 ≥5 L 1 ,

W≥ 3 B,
A 1 =WL 2 ,

wherein, L 2 represents a length of the experimental area, and W represents a width of the experimental area;
S 2 . determining a characteristic length of model ice:
S 21 . determining a target coverage ratio c of the model ice;
S 22 . according to the experimental area size A 1 obtained in step S 1 and the target ice coverage ratio c obtained in step S 21 , determining a total area A 2 of the model ice:
A 2 =cA 1 ;

S 23 . according to the bending theory of thin plate sitting on elastic foundation, determining a critical characteristic length L c of the broken ice without bending failure:

L
c

=

D
k

4

,

wherein, D represents a flexural rigidity of ice, satisfying the following equation:

D
=

Et
3

12
⁢

(

1
-

v
2

)

,

E represents an elastic modulus of ice, with the unit of Pa; t represents an actual thickness of the broken ice, with the unit of m; v is Poisson's ratio; and k represents an elastic stiffness of the base, satisfying the following equation:
k=ρ w g,
ρ w is the density of water, with the unit of kg/m 3 ; and g is the acceleration of gravity, with the unit of kg/m 2 ;
S 24 . determining the critical characteristic length l:

l
=

L
λ

,

wherein, L represents a characteristic length of the broken ice, satisfying the following condition:
L≤L c ;

S 25 . according to the critical characteristic length l of the model ice, determining a characteristic length l n of each size of the model ice in the ship ice resistance model experiment;
S 3 . determining a quantitative proportion of the model ice for each size under the target coverage ratio c of the model ice:

N
⁡

(

l
n

)

=

{

β
1

⁢

l
n

-

α
1

,

l
n

∈

[

1
,
40

]

β
2

⁢

l
n

-

α
2

,

l
n

∈

[

40
,
1500

]

wherein, N(l n ) represents a number of the model ice with the size l n , α 1 , a 2 , β 1 and β 2 are coefficients, α 1 =1.15, α 2 =1.87; when the characteristic length l n of the model ice is in a range of [l 1 ,l 2 ], the total area of the model ice satisfies the following equation:

A
=

∫

l
2

l
1

⁢

n
a

⁡

(
x
)

⁢

s
⁡

(
x
)

Assignees

• Univ Dalian Tech

Inventors

• Zhang Guiyong
• Jiang Yuyan
• Zong Zhi
• Sun Zhe
• Wang Hao
• Yang Biye
• Yin Zhihong
• Liu Ning

Classifications

• G01M10/00 Primary

  Hydrodynamic testing; Arrangements in or on ship-testing tanks or water tunnels · CPC title

• B63B71/20 Primary

  using towing tanks or model basins for designing · CPC title

• B63B2211/06

  Operation in ice-infested waters · CPC title

• C09K3/24

  for simulating ice or snow · CPC title