Systems and methods for designing and modeling pressure-compensating drip emitters, and improved devices in view of the same

Patent metadata

Field	Value
Publication number	US-2022046869-A1
Application number	US-202117402209-A
Country	US
Kind code	A1
Filing date	Aug 13, 2021
Priority date	Aug 13, 2020
Publication date	Feb 17, 2022
Grant date	—

Abstract

Systems and methods for modeling ways to best design pressure-controlled drip irrigation emitters are provided. The systems and methods are designed to help reduce activation pressure while maintaining a substantially constant, desirable flow rate in an irrigation system. Various parameters that impact the activation pressure and the flow rate can be adjusted to assist in finding optimal designs. The parameters can at least include one or more of resistances in a flow path, resistances in a membrane cavity, a membrane, or placement of a membrane with respect to a membrane cavity. Optimal designs for such emitters based on the discloses systems and methods are provided, including at least one exemplary embodiment in which a length of a flow path is substantially reduced as compared to known emitters.

First claim

1 . A method of reducing an activation pressure in a pressure-controlled drip irrigation emitter while maintaining a substantially constant flow rate, comprising:
adjusting at least one of the following variables that impacts an activation pressure and a flow rate of a pressure-controlled drip irrigation emitter having a body by:
decreasing a resistance of a flow path formed in the body of the emitter;
decreasing a resistance of a membrane cavity formed in the body of the emitter;
decreasing a distance between a membrane disposed above a bottom surface of a membrane cavity of the body of the emitter and a top surface of a lands disposed in the membrane cavity;
decreasing a thickness of a membrane disposed above a membrane cavity of the body of the emitter;
increasing a length or a width of a membrane disposed above a membrane cavity of the body of the emitter; or
decreasing a flexural modulus of a membrane disposed above a membrane cavity of the body of the emitter,
wherein a result of the adjusting is an activation pressure approximately in the range of about 0.1 bar to about 0.3 bar.

2 . The method of claim 1 , wherein adjusting at least one of the following variables that impacts an activation pressure and a flow rate of a pressure-controlled drip irrigation emitter having a body comprises adjusting at least two of the variables.

3 . The method of claim 2 , wherein one of the variables comprises the resistance of the flow path formed in the body of the emitter.

4 . The method of claim 2 , wherein one of the variables comprises the distance between the membrane disposed above the bottom surface of the membrane cavity of the body of the emitter and the top surface of the lands disposed in the membrane cavity.

5 . The method of claim 2 , wherein one of the variables comprises the resistance of the membrane cavity formed in the body of the emitter.

6 . The method of claim 2 , wherein one of the variables comprises at least one of the length, the width, or the thickness of the membrane disposed above the membrane cavity of the body of the emitter.

7 . The method of claim 2 , wherein one of the variables comprises the flexural modulus of the membrane disposed above the membrane cavity of the body of the emitter.

8 . The method of claim 1 , wherein decreasing a resistance of a flow path formed in the body of the emitter further comprises decreasing a length of the flow path.

9 . The method of claim 1 , wherein decreasing a flexural modulus of a membrane disposed above a membrane cavity of the body of the emitter further comprises decreasing at least one a Young's modulus of the membrane or a Poisson's ratio of the membrane.

10 . The method of claim 1 , wherein adjusting at least one of the variables that impacts an activation pressure and a flow rate of a pressure-controlled drip irrigation emitter having a body is controlled by:

P
act

=

Dh
lands

⁡

(

K
path

+

K
chamber

)

α
1

⁢

K
path

+

α
2

⁢

K
chamber

⁢

π
⁢

⁢

r
out
2

ab

,

wherein:
P act is the activation pressure,
D is the flexural modulus,
h lands is the distance between the membrane disposed above the bottom surface of the membrane cavity of the body of the emitter and the top surface of the lands disposed in the membrane cavity,
K path is the resistance of the flow path formed in the body of the emitter,
K chamber is the resistance of the membrane cavity formed in the body of the emitter,
α 1 is a first constant of a deflection expression of the membrane,
α 2 is a second constant of a deflection expression of the membrane,
r is a radius of an outlet formed in the membrane cavity,
a is a length of the membrane cavity, and
b is a width of the membrane cavity.

11 . The method of claim 1 , wherein adjusting at least one of the following variables that impacts an activation pressure and a flow rate of a pressure-controlled drip irrigation emitter having a body is controlled by:

Q
act

=

(

Dh
lands

α
1

⁢

K
path

+

α
2

⁢

K
chamber

⁢

π
⁢

⁢

r
out
2

ab

)

1
2

,

wherein:
Q act is the activation pressure,
D is the flexur

Assignees

• Massachusetts Inst Technology

Inventors

• Sokol Julia
• NARAIN Jaya
• Winter V Amos Greene
• Costello Jeffrey
• Kumar Dheekshita
• Mclaurin Tristan J

Classifications

• A01G25/006

  Tubular drip irrigation dispensers mounted coaxially within water feeding tubes · CPC title

• A01G25/023 Primary

  Dispensing fittings for drip irrigation, e.g. drippers · CPC title

• Y02A40/22

  Improving land use; Improving water use or availability; Controlling erosion · CPC title

• G06F2113/14

  Pipes · CPC title

• G06F30/28

  using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD] · CPC title