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Simulation for The Propeller Loading of Marine Electrical Propulsion Based on

Matlab jiang pan

School of Energy and PowerEngineering

Wuhan University ofTechnology

Wuhan, [email protected]

Yao Yunan




Fan Shidong




Abstract With the requirement of energy-saving,

environmental protection, control performance

and military strategy.The improvement of ship

electric propulsion technology has become an

important direction for future development of

ship.First according to the Chebyshev Polynomial

to fitting Four-quadrant propeller characteristic

chart,then establish the mathematical model of

paddle.Last use matlab to create the simulation

model,then run the model to simulate the real and

dynamic working course in the no wind and head

wind environment.

Keywords -marine; electric; propulsion; simulation

I. INTRODUCTION

The accurate analysis of the propeller load

characteristics is one of the most important part

for the simulation of the electric propulsion. At

design stage for the electric propulsion system, tomeet the indicator, simulate the propulsion

system in all working condition. The existed

simulation models omitted the influence of air

resistance on the ship, and the simulation is run

in an ideal conditions. On this basis, this article

considering the air resistance and simulate the

propeller loading in no wind and head wind

situation. Therefore, the paragraph below will

introduce the propeller load characteristics for

complex conditions for further simulation.

II. FOUR QUADRANT PROPELLER EXPRESSION

The propeller thrust coefficient p K torque

coefficien M K and ratio of velocity to

revolution J are defined as follow [1]:24/ N D P K p = (1)

25/ N D M K M = (2)

DN V J p /= (3)

In the expression: pV is the velocity of

propeller; P and are thrust and torquegenerate from propeller; D is the diameter of

propeller; is seawater density.

According to different speeds and velocity,the propeller working conditions can be divided

into four quadrants. And the

coefficient p K , M K , and J are infinity. It is

called non-bounded expression. In the dynamic

expression of the propeller in full working

condition, it is usually more convenient to take

the form of bounded expression. When N and

pV are not equal to zero at the same time, the

978-1-4244-8039-5/11/$26.00 2011 IEEE

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corresponding definition is [2]:

)](/[' 2222 N DV D p K p p += (4)

)](/[' 2223 N DV Dm K pm += (5)

2/1222 )/(' N DV V J p p += (6)

From the expression (6) it could deduce:

2/1222 )/(1(/' N DV N DV J p p += (7)

Then from the two expressions above it could

deduce the relation between J and ' J :

)1/(' 2 J J J += (N>0) (7a)

)1/(' 2 J J J += (N

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III . PROPELLER MATH MODEL

Propeller torque:

23

2223

'/'

)('

J V D K

D N V D K M

pm

pm

=+= (10)

Propeller thrust:

22

2222

'/'

)('

J V D K

D N V D K P

p p

p p

=+= (11)

Due to thrust deduction coefficient:

P P P

t e

=,

the ffective thrust generated by propeller is :

22 '/')1()1( J V D K t P t P p pe

== (12)

In the expression :e P is the effective thrust ,

t is the thrust deduction coefficient .

)1( = s p V V (13)

In the expression: pV is the velocity of

propeller, sV is the velocity of ship, is

mixed flow coefficient.

The motion equation for the propeller system

is established:

R P dt dvmm e =+ /)( (14)

In the expression: m is the quality of ship ;m is the quality of water attached on the hull ;

R is the toal resistance of ship.The total resistance of the ship include:

hydrodynamic resistance 1 R and air

resistance 2 R . Firstly the drag power of a ship in

working state is calculated [3]:

LC k DV

N a s R+

=)1(3

(15)

L B 10= (16)

1003.07.0

L+= (17)

In the expression: L is length of ship; D isvessel displacement;

is correction factor;

a K is accessories influence coefficient; is

coefficients of form ; B is breadth of ship ; is ship square coefficient.

Hydrodynamic resistance calculating

formula:

s R V N R /751 = (18)

Air resistance calculating formula:

22 sb FV K R = (19)

Among them the coefficient C and b K in

the (15) and (19) are determined by the

reference[3].

In the simulation model, parameters t and are determined as follow [4]:

=

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readable. The simulation model and its sub-block

are as follows [5] :

The simulation model is built based on

mathematical model In the matlab / simulink

environment. In simulink tool box there are many

packaged blocks, which can be copied to model

window and then be connected together. As this

model is complex. here choose a subsystem,

making the model simple and easy to read. The

simulation model and subsystem model are as

follows:

simulation model of the propeller

Subsystem model

DYNAMIC LOAD CHARACTERISTICS OF THE

PROPELLER According to the parameters of electric

propulsion ship, it applies the simulation model.

The results are:

(5)Velocity of ship

(6) torque

(7)Velocity of ship

(8) torque

CONCLUSION Sea breeze has great influence on a sailing

ship, especially on maneuverability and the

loading characteristic. Analysis of above result

draws the following conclusions:

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