Laminar flow duct cooling system

• US 6,468,150 B1
• Filed: 03/30/2001
• Issued: 10/22/2002
• Est. Priority Date: 11/30/1998
• Status: Expired due to Term

• Current Assignee: NetApp, Inc.
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Robbins, Robert, Langdon, Daryl J.
• Primary Examiner(s): Joyce, Harold
• Application Number:
  US09/823,368
• Time in Patent Office: 571 Days
• Field of Search: 454/184, 361/695, 165/80.3, 165/122
• US Class Current: 454/184
• CPC Class Codes: F04D 25/0613 the electric motor being of the inside-out type, i.e. the rotor is arranged radially outside a central stator
• CPC Class Codes: F04D 25/166 using fans
• CPC Class Codes: F04D 29/545 Ducts
• CPC Class Codes: G06F 1/20 Cooling means

Abstract

A redundant cooling system with abatement of noise from cooling fans being used primarily in computer equipment and other boxes housing electronic equipment. Typically either the computer system or box housing electronic components has two parallel side panels, a front panel, and a back panel upon which cooling fans are mounted to draw air across various electronic components and through the box for heat dissipation. The cooling system includes an airflow grille attached to one end of a laminar flow duct and two adjacent cooling fans mounted to the other end of a laminar flow it duct which includes a Venturi opening on the top panel of the laminar flow duct to facilitate laminar flow through the laminar flow duct at a distance before the cooling fans and at a distance after the cooling fans.

Claims

1. A cooling system which reduces aerodynamic or electromagnetic noise comprising:

a laminar flow duct, one side of said laminar flow duct defining a first planar region;

one or more cooling fans in a housing, each fan having a toroidal fan opening and disposed for providing positive airflow over the first planar region, along a first linear axis substantially parallel to the first planar region;

an airflow grille, defining a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis; and

a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct, said laminar flow duct being coupled on a first end to the housing for said one or more cooling fans and on a second end to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis;

wherein said cooling system reduces aerodynamic or electromagnetic noise.

2. A cooling system of claim 1, wherein said cooling fans include a plurality of separate cooling fans each of said plurality in a separate housing defining a separate cooling fan disposed for providing positive laminar airflow parallel to said first linear axis and into a second laminar flow region.

3. A cooling system as in claim 1, wherein said laminar flow duct defines a Venturi opening, said Venturi opening being operative in conjunction with said cooling fans to provide airflow through said Venturi opening from a region both upstream and above a region of said laminar flow duct containing said Venturi opening wherein airflow is parallel to said first laminar flow region.

4. A cooling system as in claim 2 wherein each of said plurality of separate cooling fans provides positive laminar airflow in parallel to one another.

5. A cooling system as in claim 2 wherein said grille opening is equal to or greater than said toroidal fan opening such that aerodynamic and electromagnetic noise are minimized.

6. A cooling system as in claim 3 wherein said laminar flow duct has the geometry of a rectangular solid.

7. A cooling system as in claim 3 wherein said Venturi opening has a rectangular shape.

8. A cooling system which reduces aerodynamic and electromagnetic noise comprising:

a laminar flow duct, one side of said laminar flow duct defining a first planar region;

one or more cooling fans in a housing, each fan having a toroidal fan opening and disposed for providing positive airflow over the first planar region, along a first linear axis substantially parallel to the first planar region;

an airflow grille, defining a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis; and

a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct, said laminar flow duct being coupled to the housing for said one or more cooling fans and to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis,

wherein said laminar flow duct acts as an RF collimator to reduce electromagnetic noise.

9. A method for cooling electronics and minimizing aerodynamic or electromagnetic noise, including steps for:

blowing incoming air with one or more cooling fans in a housing, disposed for providing positive airflow over a first planar region defined by one side of a laminar flow duct, along a first linear axis substantially parallel to the first planar region;

receiving air through an airflow grille which defines a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis; and

receiving air through a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct, said laminar flow duct being coupled on a first end to a housing for said one or more cooling fans and on a second end to said airflow grille, and said laminar flow duct-being substantially parallel to said first linear axis;

wherein said method for cooling reduces aerodynamic or electromagnetic noise.

10. A method as in claim 9 wherein said cooling fans include a plurality of separate cooling fans each of said plurality in a separate housing defining a separate cooling fan disposed for providing positive laminar airflow parallel to said first linear axis.

11. A method as in claim 9 wherein said laminar flow duct defines a Venturi opening, said Venturi opening being operative in conjunction with said cooling fans to provide airflow through said Venturi opening from a region both upstream and above a region of said laminar flow duct containing said Venturi opening wherein airflow is parallel to said first laminar flow region.

12. A method as in claim 10 wherein each of said plurality of separate cooling fans provides positive laminar airflow in parallel to one another.

13. A method as in claim 10 wherein said grille opening is equal to or greater than said toroidal fan opening such that aerodynamic and electromagnetic noise are minimized.

14. A method as in claim 11 wherein said laminar flow duct has the geometry of a rectangular solid.

15. A method as in claim 11 wherein said Venturi opening has a rectangular shape.

16. A method for cooling electronics and minimizing aerodynamic and electromagnetic noise, including steps for:

blowing incoming air with a set of one or more cooling fans in a housing, disposed for providing positive airflow over a first planar region defined by one side of a laminar flow duct, along a first linear axis substantially parallel to the first planar region;

receiving air through an airflow grille which defines a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis; and

receiving air through a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct, said laminar flow duct being coupled to a housing for said one or more cooling fans and to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis,

wherein said laminar flow duct acts as an RF collimator to reduce electromagnetic noise.

17. A method for cooling electronics and minimizing aerodynamic and electromagnetic noise, including steps for:

blowing incoming air with one or more cooling fans in a housing, each fan having a toroidal fan opening and disposed for providing positive airflow over a first planar region defined by one side of a laminar flow duct, along a first linear axis substantially parallel to the first planar region;

receiving air through an airflow grille which defines a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis wherein said grille opening is equal to or greater than said toroidal fan opening such that aerodynamic and electromagnetic noise are minimized; and

receiving air through a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct wherein said laminar flow duct has a geometry of a rectangular solid such that said laminar flow duct defines a Venturi opening, said Venturi opening being operative in conjunction with said one or more cooling fans to provide airflow through said Venturi opening from a region both upstream and above a region of said laminar flow duct containing said Venturi opening wherein airflow is parallel to said first laminar flow region, said laminar flow duct being coupled on a first end to a housing for said one or more cooling fans and on a second end to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis wherein said laminar flow duct acts as an RF collimator to reduce electromagnetic noise.

18. A cooling system which reduces aerodynamic or electromagnetic noise comprising:

a laminar flow duct, one side of said laminar flow duct defining a first planar region;

one or more cooling fans in a housing, each fan having a toroidal fan opening and disposed for blowing air over the first planar region, along a first linear axis substantially parallel to the first planar region;

an airflow grille, defining a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis; and

a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct, said laminar flow duct being coupled on a first end to the housing for said one or more cooling fans and on a second end to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis;

wherein said cooling system reduces aerodynamic or electromagnetic noise.

19. A cooling system as in claim 18, wherein said cooling fans include a plurality of separate cooling fans each of said plurality in a separate housing defining a separate cooling fan disposed for blowing air so as to provide laminar airflow parallel to said first linear axis.

20. A cooling system as in claim 18, wherein said laminar flow duct defines a Venturi opening, said Venturi opening being operative in conjunction with said cooling fans to provide airflow through said Venturi opening from a region both upstream and above a region of said laminar flow duct containing said Venturi opening wherein airflow is parallel to said first laminar flow region.

21. A cooling system as in claim 19 wherein each of said plurality of separate cooling fans blows air so as to provide laminar airflow in parallel to one another.

22. A cooling system as in claim 19 wherein said grille opening is equal to or greater than said toroidal fan opening such that aerodynamic and electromagnetic noise are minimized.

23. A cooling system as in claim 20 wherein said laminar flow duct has the geometry of a rectangular solid.

24. A cooling system as in claim 20 wherein said Venturi opening has a rectangular shape.

25. A cooling system which reduces aerodynamic and electromagnetic noise comprising:

a laminar flow duct, one side of said laminar flow duct defining a first planar region;

one or more cooling fans in a housing, each fan having a toroidal fan opening and disposed for blowing air over the first planar region, along a first linear axis substantially parallel to the first planar region;

an airflow grille, defining a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis; and

a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct, said laminar flow duct being coupled to the housing for said one or more cooling fans and to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis,

wherein said laminar flow duct acts as an RF collimator to reduce electromagnetic noise.

26. A cooling system which reduces aerodynamic and electromagnetic noise comprising:

a laminar flow duct, one side of said laminar flow duct defining a first planar region;

one or more cooling fans in a housing, each fan having a toroidal fan opening and disposed for blowing air over the first planar region, along a first linear axis substantially parallel to the first planar region;

an airflow grille, defining a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis wherein said grille opening is equal to or greater than said toroidal fan opening such that aerodynamic and electromagnetic noise are minimized; and

a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct wherein said laminar flow duct has a geometry of a rectangular solid such that said laminar flow duct defines a Venturi opening, said Venturi opening being operative in conjunction with said one or more cooling fans to provide airflow through said Venturi opening from a region both upstream and above a region of said laminar flow duct containing said Venturi opening wherein airflow is parallel to said first laminar flow region, said laminar flow duct being coupled on a first end to a housing for said one or more cooling fans and on a second end to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis, wherein said laminar flow duct acts as an RF collimator to reduce electromagnetic noise.

27. A method for cooling electronics and minimizing aerodynamic or electromagnetic noise, including steps for:

blowing incoming air with one or more cooling fans in a housing, disposed for blowing over a first planar region defined by one side of a laminar flow duct, along a first linear axis substantially parallel to the first planar region;

receiving air through an airflow grille which defines a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis; and

receiving air through a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct, said laminar flow duct being coupled on a first end to a housing for said one or more cooling fans and on a second end to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis;

wherein said method for cooling reduces aerodynamic or electromagnetic noise.

28. A method as in claim 27 wherein said cooling fans include a plurality of separate cooling fans each of said plurality in a separate housing defining a separate cooling fan disposed for blowing air so as to provide laminar airflow parallel to said first linear axis.

29. A method as in claim 27 where said laminar flow duct defines a Venturi opening, said Venturi opening being operative in conjunction with said cooling fans to provide airflow through said Venturi opening from a region both upstream and above a region of said laminar flow duct containing said Venturi opening wherein airflow is parallel to said first laminar flow region.

30. A method as in claim 28 wherein each of said plurality of separate cooling fans blows air so as to provide laminar airflow in parallel to one another.

31. A method as in claim 28 wherein said grille opening is equal to or greater than said toroidal fan opening such that aerodynamic and electromagnetic noise are minimized.

32. A method as in claim 29 wherein said laminar flow duct has the geometry of a rectangular solid.

33. A method as in claim 29 wherein said Venturi opening has a rectangular shape.

34. A method for cooling electronics and minimizing aerodynamic and electromagnetic noise, including steps for:

blowing incoming air with a set of one or more cooling fans in a housing, disposed for blowing over a first planar region defined by one side of a laminar flow duct, along a first linear axis substantially parallel to the first planar region;

receiving air through an airflow grille which defines a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis; and

receiving air through a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct, said laminar flow duct being coupled to a housing for said one or more cooling fans and to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis,

wherein said laminar flow duct acts as an RF collimator to reduce electromagnetic noise.

35. A method for cooling electronics and minimizing aerodynamic and electromagnetic noise, including steps for:

blowing incoming air with one or more cooling fans in a housing, each fan having a toroidal fan opening and disposed for blowing over a first planar region defined by one side of a laminar flow duct, along a first linear axis substantially parallel to the first planar region;

receiving air through an airflow grille which defines a second planar region substantially perpendicular to said first linear axis, said airflow grille defining a set of through-holes substantially parallel to said first linear axis wherein said grille opening is equal to or greater than said toroidal fan opening such that aerodynamic and electromagnetic noise are minimized; and

receiving air through a first laminar flow region disposed between said cooling fans and said airflow grille, said first laminar flow region defined by said laminar flow duct wherein said laminar flow duct has a geometry of a rectangular solid such that said laminar flow duct defines a Venturi opening, said Venturi opening being operative in conjunction with said one or more cooling fans to provide airflow through said Venturi opening from a region both upstream and above a region of said laminar flow duct containing said Venturi opening wherein airflow is parallel to said first laminar flow region, said laminar flow duct being coupled on a first end to a housing for said one or more cooling fans and on a second end to said airflow grille, and said laminar flow duct being substantially parallel to said first linear axis wherein said laminar flow duct acts as an RF collimator to reduce electromagnetic noise.