Propeller operation

Patent metadata

Field	Value
Publication number	US-9475572-B2
Application number	US-201214008753-A
Country	US
Kind code	B2
Filing date	Mar 29, 2012
Priority date	Mar 31, 2011
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A method of and apparatus for operating a propeller, the propeller moving through a fluid, the method including: measuring a value of a property of the fluid (e.g. a parameter related to the density of the fluid); measuring a value of a parameter, the parameter related to one or more forces applied to the propeller (e.g. a torque applied to the propeller) or derived at least in part from the action of the propeller (e.g. a thrust produced by the action of the propeller, a drag produced by the action of the propeller, or a velocity produced by the action of the propeller); and controlling the propeller depending on a function of the measured value of the property of the fluid and the measured value of parameter. The propeller may be a propeller on an aircraft.

First claim

The invention claimed is:

1. A method of operating a propeller, the propeller moving through a fluid, the method comprising:
measuring a value of a property of the fluid;
measuring a value of a parameter, the parameter being related to one or more forces applied to the propeller or derived at least in part from action of the propeller;
using the measured value of the property of the fluid and the measured value of the parameter, determining a desired rotational speed for the propeller; and
controlling the propeller such that the rotational speed of the propeller is equal to the determined rotational speed.

2. The method according to claim 1 , wherein measuring the value of the parameter comprises:
measuring a value for thrust produced at least in part by the action of the propeller.

3. The method according to claim 1 , wherein measuring the value of the parameter comprises:
measuring a value of a parameter related to drag produced at least in part by the action of the propeller.

4. The method according to claim 1 , wherein measuring the value of the parameter comprises:
measuring a value for a torque applied to the propeller; and
measuring a value for a velocity produced at least in part by the action of the propeller.

5. The method according to claim 2 , wherein determining a rotational speed for the propeller comprises calculating:

n
2

=

T

3
⁢

⁢

a
0

⁢
ρ
⁢

⁢

D
4

where:
n is the rotational speed for the propeller;
T is the measured thrust produced by the action of the propeller;
ρ is a density of the fluid;
D is a diameter of the propeller; and
a 0 is a constant.

6. The method according to claim 3 , wherein determining a rotational speed for the propeller comprises calculating:

n
2

=

F
D

3
⁢

a
0

⁢

ρη
i

⁢
N
⁢

⁢

D
4

where:
n is the rotational speed for the propeller;
F D is a drag force;
η i is an installation efficiency factor;
N is a total number of propellers;
ρ is a density of the fluid;
D is a diameter of the propeller; and
a 0 is a constant.

7. The method according to claim 4 , wherein determining a rotational speed of the propeller comprises calculating:

n
=

-

(

b
1

⁢
V

D

)

+

(

b
1

⁢
V

D

)

2

-

4
⁢

⁢

b
0

⁡

(

b
2

⁢

V
2

D
2

-

2
⁢
π
⁢

⁢
Q

ρ
⁢

⁢

D
5

)

2
⁢

⁢

b
0

where:
n is the rotational speed for the propeller;
V is the measured value for the velocity produced by the action of the propeller;
Q is the measured value for the torque applied to the propeller;
p is property density of the fluid;
D is a diameter of the propeller;
b o is a constant;
b 1 is a constant; and
b 2 is a constant.

8. The method according to claim 5 , wherein a constant is determined by approximating an optim

Assignees

• Collingbourne Peter Wayne
• Bae Systems Plc

Inventors

• Collingbourne Peter Wayne

Classifications

• B64C19/00 Primary

  Aircraft control not otherwise provided for · CPC title

• B64C11/305 Primary

  characterised by being influenced by other control systems, e.g. fuel supply · CPC title

• Y02T50/66

  Cross-Sectional Technologies · mapped topic

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title