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TheAnalysisofFloodedSubmarineMotionStateVaryingFromDifferent.pdf

The Analysis of Flooded Submarine Motion State Varying From Different

Attack Angle Under Blowing Ballast Tank

LIU Hui, PU Jin-yun, LI Qi-xiu, WU Xiang-jun

College of Power Engineering, Naval Univ. Of Engineering

Wuhan, China

[email protected]

Keywords: Recovery maneuver; Large angle of attack; Hydrodynamics; Forecast.

Abstract. The paper establishes emergency recovery maneuver model of six degree of freedom and

blowing ballast compartment model of high pressure air. Based on standard maneuver equation,

considering the influence of large angle of attack to hydrodynamics coefficient, correct the standard

equation through supplementing hydrodynamics items. Applying large and small angle of attack

system to simulate and calculate state parameters, and find the occasion of large of attack, the

influence of initialization velocity and depth to change of angle of attack. The results prove that large

angle of attack system is significant to forecast the state parameters.

Introduction

Submarine as one of the most important deterrent of modern navy, how to improve the safety and

mobility are an important direction of development of countries in the Navy. In the course of the

navigation and fighting, when submarine damage caused by collision or attack by enemy

anti-submarine weapons, the submarine would be a negative buoyancy and trim moment. If you do

not take or do not actively take proper control measures, under the negative buoyancy of the hull,

hydrodynamic of the hull and the propeller thrust effect, the submarine will be beyond the limits of

depth of the submarine in a very short period of time, and the submarine pressure hull caused by the

pressure loss, or the submarine hit bottom in shallow water [1,2].

Based on submarine standard motion equation [3]

delivered by ITTC,through data regress of the

results of ship model experiment, the paper acquires the added hydrodynamic items caused by the

motion state of high angle of attack, and modify the space motion equation. Combining the added

force model, the paper established the high pressure air

blowing main ballast tank model and emergency recovery

maneuver model. Compared to the difference of small attack

angle and high attack angle, the paper summarizes the

influence of the various parameters to emergency floating

maneuver and analyzes the motion characteristic of submarine

during emergency maneuver.

Emergency Retrieve Maneuvering Model of Submarine

Coordinate System. To research the maneuvering motion law of submarine and fix the position and

pose of a moving submarine [4]

, the absolute coordinate system ξηζ−E and relative coordinate

system xyzO− attaching to the submarine are established , which are shown as Fig.1.

In Fig.1, X , Y and Z represents axis force, side force and vertical force on the submarine

respectively; and K , M and N represents heeling moment, trim moment and drifting moment of the

submarine respectively.

x y

z

XY

Z K

M

N

)G(O

E ξ

η

ζ

Fig.1. Coordinate system

Applied Mechanics and Materials Vols. 336-338 (2013) pp 442-445 Online available since 2013/Jul/15 at www.scientific.net © (2013) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMM.336-338.442

All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 165.215.209.15, ProQuest-16/10/13,01:52:59)

Submarine Space Motion Equation. This paper choose the submarine space motion model with six

degree of freedom released by DTNSRDC in 1967 as the basic model [5]

.

The motion Equation of Large Angle of Attack . Emergency recovery motion equation of flooded

compartment is different from normal maneuvering motion,and it belongs to maneuvering of high

angle of attack.When submarine maneuvers in small angle of attack, mainly affected by the fluid

viscous resistance, but when submarine maneuvers in the high attack angle, except for viscous

resistance, the inertial component of resistance will be significantly enhanced.Especially when the

attack angle of submarine is greater than 50°,submarine expresses highly nonlinear characteristics.

According to ship model hydrodynamics experiment of large angle of attack and different propeller

load, the paper analyzes the hydrodynamic coefficient, and acquires additional hydrodynamic items of

six motion direction, which mainly represents fluid inertia resistance items [6]

.Combining the basic

maneuvering equation, established motion equation of high angle of attack.Due to space limitations,

the paper don’t specifically describe in the text.

Hydrodynamic Coefficients. The hydrodynamic coefficient applied in this paper is obtained from

limited ship model hydrodynamics experiment of large angle of attack and different propeller

load [6]

.Two sets of hydrodynamic coefficient are obtained from the experiment:the first is under the

situation of low angle of attack(angle of attack ]12,12[ °°−∈α ); the second is under the situation of high

angle of attack(angle of attack ]50,50[ °°−∈α ).

Model of Blowing Ballast Tank System

Model of Blowing Ballast Compartment. In the process of blowing ballast compartment, the

pressure F P declines rapidly in the air cylinder, in which the gas flow can be considered isentropic

because of its slow heat exchange. In the ballast compartment the accumulated gas flow can be seen as

isentropic expansion. This paper gained the model of blowing ballast compartment by dint of Laval

nozzle model, combining the instance of actual submarine.

Gas Flux in High-pressure Air Cylinder.

1

1

1 ) 1

2 (,)

1

2 ( −

+

+ =

+ ≤ k

k

F

Ft F

k

k

F

B

k k

RT

CpA m

kp

p �

(1)

))()(( 1

2 ,1)

1

2 (

12

1 k

k

F

Bk

F

B FFtF

F

Bk

k

p

p

p

p

k

k pCAm

p

p

k

+

− − −

=≤≤ +

ρρρρ� (2)

Pressure in Ballast Compartment.

B

B BB

B

B

V

dt

dV pRT

dt

dm

dt

dp −

= (3)

Discharged Water Flux in Ballast Compartment.

) )(2

(∑∑∑ −

=== i

WBi Hihi

i

hihihi

i

Bi

pp ACvACqQ

ρρρρ (4)

F m and

B m represents the mass of gas in air flask and in ballast compartment respectively;

t A is

the area of Laval nozzle ;C is valve coefficient( 10 ≤≤ C );k is isentropic coefficient, 4.1=k ; R is Gas

Constant 287.1J/(kg·K ); Q is discharged water flux; W p is the pressure of environment;

h C is

coefficient of losses, in this paper 7.0= h C ;i is the serial number of the ballast compartment.

Applied Mechanics and Materials Vols. 336-338 443

The Simulation and Analysis of Submarine Emergency Recovery

Recovery Maneuvering Simulation System. The simulation system consists of initialization state

setting module, damage setting module, recovery scheme setting module and real-time display

module. After simulation, firstly setting submarine’s initialization state and damage situation. If

blowing ballast compartment, the simulation system will record the time of blowing automatically.

The simulation system can choose calculation system through judging submarine’s angle of attack,

also can set in advance. The system solve the non-linear differential equation with Runge-Kutta of

four steps in fixed pace, and the fixed step is 1/10 second. The submarine’s state parameters will

refurbish each second and are displayed in real-time. When simulation finish, the system can output

the recovery scheme and submarine’s real-time parameters in whole simulation stage. The simulation

flow is as following Fig.2.

Analysis of Simulation Results. When compartment broken in submarine’s bow and amidships,

before the advent of high angle of attack, the results of simulation and calculation is approximation by

the large angle of attack and the small angle system under the same conditions, and the reasons is the

nonlinear items caused by large angle of attack does not work. But when large angle of attack appears,

the calculation results show that state parameters of the submarine is obviously different calculated by

different computing system from the results, after the big angle of attack angle, the results using large

angle of attack system is more consistent with the actual situation.

When compartment broken in submarine’s bow and

midship,compared to variety of measures ,the submarine

will most likely appear motion state of large angle of attack

under taking "not manipulating rudder, not blowing ballast

tanks” and "not manipulating rudder, not blowing ballast

tanks”. The reasons are that the submarine’s pose cannot be

controlled when not manipulating rudder, and the

submarine will appear large angle of attack. In order to

avoid the emergence of motion state of large angle of

attack, it is necessary to recovery submarine by measures of

manipulating rudder and increase the speed of the

submarine during recovery course.

When compartment broken in submarine’s stern, the

submarine will lose power, if taking measures of "stopping

deceleration, blowing ballast tanks " and using small angle

of attack system to recovery the submarine, submarine will

appear divergent, mutation and so on. When calculating the

motion state using of large angle of attack system, because

the equations of motion correction attached, the calculation

results were amended, does not appear above situation, and

the calculated results closer to the actual situation.

According to compartment broken in submarine’s stern, the submarine is usually the motion state of

large angle of attack, so it will play a key role to accurately forecast submarine’s motion state by

taking large angle of attack simulation model.

Numerical Example. This paper chooses the representative condition that the IV compartment is

flooded with initial depth being 200m, initial speed being 4 knots, diameter of crevasse being 100mm.

Taking blowing mid and stern ballast compartment and steering rudder to retrieve submarine. The

paper simulate the process with small angle of attack system and large angle of attack system

respectively. The real-time developing trends of submarine’s angle of attack(AOA), depth(H), roll

angle, pitch angle and axis velocity(Vx),floating velocity(Vceta) are shown as Fig.3.

Fig.2. The simulation flow of emergency recovery motion

flooded compartment of submarine

The setting of Initialization parameters

Solveing motion equation of six freedom degree

The setting of damage

Making emergency maneuver plan

Making emergency blowing plan

Whether relieveing tank's pressure

Whether discarding ballast

Reconfirm hydrodynamic coefficients

The state evaluation of real time

Whether changing recovery plan

Matching between attack angle and hydrodynamic

Yes

No

Ending the simulation process

Analyzing the motion characteristic of submarine

Yes

No

444 Industrial Instrumentation and Control Systems II

-100

-80

-60

-40

-20

0

20

40

60

80

100

0 50 100 150 200 250 300 350

t(s)

A t t a c k a n g l e ( d e g )

small angle of attack

high angle of attack

100

200

300

400

500

0 50 100 150 200 250 300 350 t(s)

D e p t h ( m )

s mall angle of attack

high angle of attack

-20

0

20

40

60

80

100

0 50 100 150 200 250 300 350

t(s)

R o l l ( d e g )

s mall angle of attack

high angle of attack

-40

-30

-20

-10

0

10

20

0 50 100 150 200 250 300 350

t(s)

P i t c h (

d e g )

small angle of attack

high angle of attack

-6

-4

-2

0

2

4

6

8

10

0 50 100 150 200 250 300 350

t(s)

V X ( m / s )

small angle of attack

high angle of attack

-1

0

1

2

3

4

5

0 50 100 150 200 250 300 350

t(s)

V c e t a ( m / s )

small angle of attack

high angle of attack

Fig.4 . State parameters’s change of flooded compartment in submarine’s middle

The Fig.3 give the simulation results with small angle of attack system and large angle of attack

system respectively, and the conclusion is obvious that simulation results of small angle of attack are

abrupt, not constringe and far from nicety, due to submarine maneuver in large angle of attack. We

can see that the angle of attack of submarines nearly 80 degrees during recovery process, far beyond

the motion state of small angle range. The state parameters calculated by system of high angle of

attack are analyzed, and the results correspond with the actual situation. Comparing to limited ship

model experiments, the results applied hydrodynamics coefficients of large angle of attack are

accurate.

Conclusions

Based on submarine standard motion equation, considering that submarine usually maneuvers in

large angle of attack, increasing the additional inertia hydrodynamic items of motion state of large

angle of attack to amend the standard equation. According to the emergency recovery course of

flooded compartment, using the state model of small angle and large angle of attack to simulate and

calculate respectively, found that the results vary widely by using of small angle system and high

angle of attack system, and when submarine appears large angle of attack, the result simulated by

system of small angle of attack is unreasonable. So it is special significance that the accurate

hydrodynamics coefficients to forecast submarine’s maneuverability.

References

[1] SHI Shengda. Submarine Controlling , Defense Industry Press, Beijing,18-20(1995).

[2] DAI Yuliang. Motion Analysis and controlling Research of Submarine Emergency Surfacing,

Wuhan University of Technology, Wuhan,20-25( 2007).

[3] Wang W, Wang Y , Yin K . Modeling and Simulation of Six DOF Maneuvering for Submarine.

International Conference on Navigation ,Guidance and Control , Harbin Engineering University Pr,

Harbin, 428-432(2001).

[4] Joonyoung K,Kihun K.Estimation of Hydrodynamic Coefficients for an AUV Using Nonlinear

Obserbers,IEEE Journal of oceanic Engineering, 27(4),830-840(2002).

[5] Gentler. Standard equation of motion for submarine simulation,DTNSRDC Report 2510,

19-23(1967).

[6] Jin Tao, Yang Feng,Wang Jingqi.Submerged maneuverability of flooded submarine with large

angle of attack, Journal of Huazhong University of Science and Technology(Nature Science Edition

), 36(12),79-82(2008).

Applied Mechanics and Materials Vols. 336-338 445

Industrial Instrumentation and Control Systems II 10.4028/www.scientific.net/AMM.336-338 The Analysis of Flooded Submarine Motion State Varying from Different Attack Angle under Blowing

Ballast Tank 10.4028/www.scientific.net/AMM.336-338.442

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