Pin fin with non-uniform cross section

Abstract

The invention relates to a pin fin having a non-uniform cross-section. A heat sink is disclosed comprising a substrate and a plurality of pin fins (20) comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, the first pin comprising a first end (24) coupled to the substrate, a second end (26) opposite the first end, a first portion (28) and a second portion (30), the first pin has a first portion extending from the first end to the second portion, the first portion of the first pin having a first cross-sectional shape taken along the length of the pin fin, and the second portion of the first pin having a second cross-sectional shape taken along the length of the pin fin, the first cross-sectional shape is selected from a predetermined list comprising an ellipse, a circle, and an airfoil, and the second cross-sectional shape is selected from the predetermined list and is different from the first cross-sectional shape.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefits of U.S. Provisional Application No. US 63 / 509602, filed on June 22, 2023, and U.S. Patent Application No. US18 / 613704, filed on March 22, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to pin fins for heat sinks and, for example, pin fins having a non-uniform cross-section. Background Art

[0004] A heat sink is a conventional form for dissipating heat from a heat generating device. The heat sink includes pin fins for dissipating heat, wherein the pin fins include a uniform cross-section along the length of the pin fins. The pin fins may have an inverse relationship between heat transfer and pressure drop of a fluid passing between the pin fins, wherein increasing heat transfer causes a greater pressure drop, and a greater pressure drop reduces fluid flow through the pin fins, thereby reducing heat transfer from the pin fins. Therefore, an alternative pin fin for maximizing heat transfer may be desired. Summary of the invention

[0005] In one general aspect, a heat sink is disclosed, comprising: a base plate; and a plurality of pin fins, the plurality of pin fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, the first pin comprising a first end coupled to the base plate, a second end opposite the first end, a first portion and a second portion, the first portion extending from the first end to the second portion, the first portion of the first pin having a first cross-sectional shape taken along the length of the pin fin, the second portion of the first pin having a second cross-sectional shape taken along the length of the pin fin, the first cross-sectional shape being selected from a predetermined list including an ellipse, a circle, and an airfoil, and the second cross-sectional shape being selected from the predetermined list and being different from the first cross-sectional shape.

[0006] In another general aspect, a heat sink assembly is disclosed, comprising: a base plate; a housing enclosing the base plate and containing a fluid; and a plurality of pin fins coupled to the base plate, the plurality of pin fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, each of the plurality of pin fins comprising a first end coupled to the base plate, an opposite second end, a first portion and a second portion, each of the plurality of pin fins being spaced apart at the first end, the first portion extending from the first end to the second portion, the first portion having a first cross-sectional shape taken along the length of the pin fin, the second portion having a second cross-sectional shape taken along the length of the pin fin, the second cross-sectional shape being an airfoil, and the first cross-sectional shape not being an airfoil.

[0007] In yet another general aspect, a heat sink is disclosed, comprising: a base plate; and a plurality of pin-type fins, the plurality of pin-type fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, each of the plurality of pin-type fins comprising a first end coupled to the base plate, a second end opposite to the first end, a first portion and a second portion, the first portion extending from the first end to the second portion, the plurality of pin-type fins comprising a first pin and a second pin, the first portion of the first pin being a non-streamlined body, and the second portion of the first pin being a streamlined body. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 depicts a perspective view of a heat sink assembly according to one or more embodiments of the present disclosure;

[0009] Figure 2A Describes one or more embodiments of the present disclosure. Figure 1 A perspective view of a pin-type fin of a heat sink assembly;

[0010] Figure 2B A pin-fin heat sink assembly according to one or more embodiments of the present disclosure is depicted. Figure 2A A cross-sectional view taken along line 2B-2B in FIG.

[0011] Figure 3 A flow chart of a method of forming a heat sink according to one or more embodiments of the present disclosure is described. DETAILED DESCRIPTION

[0012] First reference Figure 1, depicting a heat sink 12 assembly 10. The heat sink 12 assembly 10 includes a heat sink 12 attached to a device 14 for dissipating heat accumulated by the device 14. The device 14 may be any device 14 capable of generating heat, such as a computer component or, more specifically, an inverter pin card. The heat sink 12 assembly 10 may also include a housing 16 that encloses the heat sink 12 and contains a fluid in which the heat sink 12 is immersed. The heat sink 12 may include a base plate 18 and a plurality of pin fins 20 coupled to the base plate 18. The base plate 18 may be formed of any material capable of transferring heat from the device 14 (e.g., copper, aluminum, steel, etc.). The heat sink 12 assembly 10 may include a pump 22 configured to direct a fluid flow F through the housing 16 and past the pin fins 20 of the heat sink 12. The pump 22 may circulate the fluid through the housing 16, wherein the fluid flow F moves in a single direction past the pin fins 20. The fluid may flow from one end of the housing 16 to the opposite end of the housing 16 and then circulate through a tube or other device to move the fluid to the one end of the housing 16. In some embodiments, the fluid may be air, wherein the pump 22 is a fan that circulates air through the pin fins 20 in an open environment. However, it is contemplated and possible that the heat sink 12 is used for natural convection without the use of a pump, fan, etc., wherein the heat sink 12 rejects heat to stagnant air.

[0013] The plurality of pin fins 20 may include a first end 24 coupled to the base plate 18, an opposite second end 26, a first portion 28, a second portion 30, and a transition section 32 located at an interface 34 between the first portion 28 and the second portion 30. The plurality of pin fins 20 are each spaced apart and arranged in a plurality of rows of pin fins 20 along the base plate 18 in the longitudinal direction such that each row of pin fins 20 is spaced apart from the other rows of pin fins 20 along a transverse direction transverse to the longitudinal direction. The plurality of rows of pin fins 20 may be staggered such that a geometric center of one of the plurality of pin fins 20 is adjacent in the transverse direction to a spacing between adjacent pin fins 20 of an adjacent row. In some embodiments, the plurality of pin fins 20 may have a non-uniform spacing, with some of the pin fins 20 spaced apart and / or staggered at different distances.

[0014] Reference now Figure 2A and Figure 2B, multiple pin fins 20 can have a non-uniform cross-section, wherein a first portion 28 of each pin fin 20 has a first cross-sectional shape and a second portion 30 has a second cross-sectional shape different from the first cross-sectional shape. Each cross-sectional shape is taken along the length of the pin fin, wherein the length can be measured by an axis A extending through the first end 24, the second end 26 and the geometric center of the pin fin. It is conceivable and possible that the pin fin 20 has more than 2 different cross-sectional shapes, such as 3, 4, or more than 4 cross-sectional shapes. Each portion can have any operable shape for conductive heat transfer, such as circular, elliptical, airfoil, rectangular, etc. As used herein, elliptical can include circular. As Figure 2A and Figure 2B As depicted in FIG. 2 , the first portion 28 extends from the first end 24 to the second portion 30, wherein the first cross-sectional shape is an ellipse and the second cross-sectional shape is an airfoil. As described above, the first cross-sectional shape may be another shape that is not an airfoil. It is also conceivable and possible that the first cross-sectional shape may be an airfoil and the second cross-sectional shape may be any other shape that is not an airfoil. In other embodiments, the cross-sectional shape may include a streamlined body and a bluff body, wherein the streamlined body has a shape with a drag coefficient below a predetermined threshold, and the bluff body is a shape with a drag coefficient equal to or above a predetermined threshold. In some embodiments, the predetermined threshold is the drag coefficient of the ellipse measured in the flow direction along the length of the ellipse, wherein the length of the ellipse is the longest part of the ellipse pointing upstream. Examples of shapes that are streamlined bodies include airfoils, flat disks with the thinnest side pointing upstream, etc. Examples of shapes that are bluff bodies include flat disks with the longest side pointing upstream, circles, ellipses, etc.

[0015] Although the pin fins 20 are depicted as having non-uniform cross-sections, it is conceivable and possible that only some of the pin fins 20 have non-uniform cross-sections, with the remaining pin fins 20 having uniform cross-sections. In other embodiments, the pin fins 20 may include first and second pins having different geometrical characteristics. The different geometrical features may include different shape features, overall heights, heights of different cross-sectional shapes, any combination thereof, and the like.

[0016] The first portion 28 may include a first trailing side 40 and a first front side 42, and the second portion 30 may include a second trailing side 44 and a second front side 46. The second trailing side 44 may overlap the first trailing side 40, wherein the second trailing side 44 is thinner than the first trailing side 40. The second front side 46 may overlap the first front side 42, wherein the second front side 46 is wider than the first front side 42. The airfoil-shaped second trailing side 44 may terminate at a point or end 48, or be rounded. The point of the second trailing side 44 may be oriented in the housing 16 so that the fluid flow F passing through the housing 16 contacts the second front side 46 before contacting the second trailing side 44. In other words, as Figure 1 As shown, the second trailing side 44 is directed downstream of the fluid flow F.

[0017] The different cross-sectional shapes of the first portion 28 and the second portion 30 may form or define a step on the bottom side of the second portion 30 and the top side of the first portion 28. This section of the pin fin 20 may be tempered to remove the step, wherein the cross-sectional shape gradually changes shape to remove the step. For example, as the first portion 28 extends toward the second portion 30, the first cross-sectional shape may change from an elliptical shape to an airfoil shape along the length of the pin fin 20. Similarly, as the second portion 30 extends toward the first portion 28, the second cross-sectional shape may change from an airfoil shape to an elliptical shape along the length of the pin fin 20. As a result, the first portion 28 and the second portion 30 may each have a changing shape near the interface 34, wherein the changing shape is between an airfoil shape and an elliptical shape. The second portion 30 may have an airfoil-elliptical shape that is primarily an airfoil shape near the interface 34, and the first portion 28 may have an airfoil-elliptical shape that is primarily an elliptical shape near the interface 34. This area around the interface 34 may be referred to as a transition section 32, wherein the transition section 32 of the plurality of pin fins 20 is located at the interface 34 between the first portion 28 and the second portion 30. The transition section 32 includes some portion of each of the first portion 28 and the second portion 30, such that the transition section 32 may be a percentage of the height of each pin fin. For example, the first portion 28 may be 30% of the height of the pin fin, the second portion 30 may be 70% of the height of the pin fin, and the transition section 32 may be 10% of the height of the pin fin, wherein half of the height of the transition section 32 is included in the first portion 28, and the other half of the height of the transition section 32 is included in the second portion 30. It is conceivable and possible that the first portion 28 and the second portion 30 account for different percentages of the height of the pin fin, for example, the first portion accounts for 20% of the height of the pin fin and the second portion accounts for 80% of the height of the pin fin, or the first portion accounts for 10% of the height of the pin fin and the second portion accounts for 90% of the height of the pin fin, etc. The pin fin 20 may have different percentages of the first portion and the second portion based on the position of the pin fin 20. For example, the pin fin 20 located upstream may have a first portion that accounts for 20% of the height of the pin fin 20, and the pin fin 20 located downstream may have a first portion that accounts for 30% of the height of the pin fin 20. In addition, for example, the pin fin 20 located between the upstream pin fin 20 and the downstream pin fin 20 may have a first portion that accounts for 25% of the height of the pin fin 20. The height of the first portion may gradually change from the upstream side to the downstream side.

[0018] The transition section 32 includes a transition cross section that changes from an elliptical shape to an airfoil shape along the length of the pin fin 20 to match the elliptical shape of the first portion 28 and the airfoil shape of the second portion 30. Although specific height percentages are provided, it is conceivable and possible that the first portion 28 and the second portion 30 can account for different percentages of the height of the pin fin 20, for example, the first portion 28 accounts for 40% of the height of the pin fin 20 and the second portion 30 accounts for 60% of the height of the pin fin 20. In other embodiments, the transition section 32 can be any operable percentage of the pin fin 20, such as 1%, 5%, 15%, 20%, or any value between the above values. The height of the transition section 32 can depend on the manufacturing method, which will be described in more detail below. It is also conceivable and possible that the pin fin 20 does not include a transition section 32, so that the step is defined by the difference in cross-sectional shape at the junction of the first portion 28 and the second portion 30.

[0019] refer to Figure 3 , depicts a flow chart of a method 300 for forming the heat sink 12 assembly 10. At step 302, the method 300 may include forming a base plate 18, a first portion 28 of the pin fin 20, and a second portion 30 of the pin fin 20. The base plate 18 and the pin fin 20 may be formed by any known process, such as additive manufacturing, casting, extrusion, etc. At step 304, the method 300 may include coupling the first portion 28 of the pin fin 20 to the second portion 30 of the pin fin 20, and coupling the first end 24 of the first portion 28 to the base plate 18. The first and second portions 28, 30 of the pin fin 20 and the base plate 18 may be coupled by any known process, such as welding, or formed together during an additive manufacturing process or casting. In some embodiments where the first portion 28 and the second portion 30 of the pin fin 20 form a step at the interface 34 between the first portion 28 and the second portion 30, the method 300 may include a step 306 including blending the interface 34 between the first portion 28 and the second portion 30 of the pin fin to remove the step defined by the interface 34. The interface 34 may be blended by welding, grinding, polishing, or another method of smoothing the end in a metal structure.

[0020] In operation and reference Figures 1 to 3, the presence of the pin fin 20 causes a pressure drop in the fluid flowing through the pin fin 20, wherein the pressure drop causes a reduction in the fluid flow rate through the downstream pin fin 20. The reduced fluid flow rate reduces the amount of heat transfer at the pin fin 20 (e.g., the downstream pin fin 20) through which the reduced flow rate flows. The cross-sectional profile of the pin fin 20 produces different pressure drops and heat transfer rates. For example, an elliptical cross-section has a higher heat transfer rate and a higher pressure drop than an airfoil-shaped cross-section. Therefore, compared to an airfoil, the elliptical cross-sectional portion of the pin fin 20 located at a low-speed region of the fluid flow F near the base plate 18 increases the heat transfer rate while minimizing the pressure drop of the fluid flow. In addition, compared to an ellipse, the use of an airfoil-shaped cross-section in a high-speed region of the fluid flow F away from the base plate 18 reduces the pressure drop to maximize the fluid flow rate, thereby maximizing the heat transfer rate of the pin fin 20 compared to a pin fin of uniform cross-section.

[0021] The present disclosure may be further defined by the following terms:

[0022] 1. A heat sink, comprising: a base plate; and a plurality of pin fins, the plurality of pin fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, the first pin comprising a first end coupled to the base plate, a second end opposite to the first end, a first portion and a second portion, the first portion extending from the first end to the second portion, the first portion of the first pin having a first cross-sectional shape taken along the length of the pin fin, the second portion of the first pin having a second cross-sectional shape taken along the length of the pin fin, the first cross-sectional shape being selected from a predetermined list including an ellipse, a circle, and an airfoil, and the second cross-sectional shape being selected from the predetermined list and being different from the first cross-sectional shape.

[0023] 2. A heat sink according to claim 1, wherein at least one of the first pin and the second pin includes a transition section located at the junction between the first portion and the second portion, the transition section including a transition section that changes from the first cross-sectional shape to the second cross-sectional shape along the length of the pin-type fin.

[0024] 3. A heat sink according to claim 1, wherein the plurality of pin-type fins are arranged in a plurality of rows of pin-type fins along a longitudinal direction, so that each row of pin-type fins is spaced apart from the pin-type fins of other rows along a transverse direction, and the plurality of rows of pin-type fins are staggered so that a center of a pin-type fin among the plurality of pin-type fins is adjacent to a space between adjacent pin-type fins of an adjacent row in the transverse direction.

[0025] 4. The heat sink of clause 1, wherein the first portion accounts for at least 1% of the height of the pin fin.

[0026] 5. The heat sink of clause 1, wherein the second cross-sectional shape is an airfoil having a front side and a rear side, the front side being larger than the rear side.

[0027] 6. The heat sink according to clause 5, wherein the first cross-sectional shape is oval or circular.

[0028] 7. A heat sink assembly, the heat sink assembly comprising: a substrate; a shell, the shell encapsulating the substrate and containing a fluid; and a plurality of pin fins, the plurality of pin fins coupled to the substrate, the plurality of pin fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, each of the plurality of pin fins comprising a first end coupled to the substrate, an opposite second end, a first portion and a second portion, each of the plurality of pin fins being spaced apart at the first end, the first portion extending from the first end to the second portion, the first portion having a first cross-sectional shape taken along the length of the pin fin, the second portion having a second cross-sectional shape taken along the length of the pin fin, the second cross-sectional shape being an airfoil, and the first cross-sectional shape not being an airfoil.

[0029] 8. The heat sink assembly of clause 7, wherein the airfoil includes a front side and a rear side, the front side being larger than the rear side.

[0030] 9. The radiator assembly of clause 8, further comprising a pump configured to direct a fluid flow through the housing, wherein the front side of the airfoil is directed upstream of the fluid flow.

[0031] 10. The heat sink assembly of clause 7, wherein the first cross-sectional shape is oval or circular.

[0032] 11. The heat sink assembly of clause 7, wherein each of the plurality of pin-fins includes a transition section at a junction between the first portion and the second portion, the transition section including a transition cross-section changing from an elliptical shape to an airfoil shape along the length of the pin-fin.

[0033] 12. A heat sink assembly according to claim 7, wherein the plurality of pin fins are arranged in a plurality of rows of pin fins along a longitudinal direction, such that each row of pin fins is spaced apart from other rows of pin fins along a transverse direction, and the plurality of rows of pin fins are staggered such that a center of a pin fin among the plurality of pin fins is adjacent to a space between adjacent pin fins of an adjacent row in the transverse direction.

[0034] 13. The heat sink assembly of clause 7, wherein the first portion accounts for at least 1% of the height of the pin fin.

[0035] 14. The heat sink assembly of clause 13, wherein the first portion accounts for 1% to 40% of the height of the pin fin.

[0036] 15. The heat sink assembly of clause 7, wherein the different geometric feature is a cross-sectional shape of the first pin and the second pin.

[0037] 16. A heat sink, comprising: a substrate; and a plurality of pin-type fins, the plurality of pin-type fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, each of the plurality of pin-type fins comprising a first end coupled to the substrate, a second end opposite to the first end, a first portion and a second portion, the first portion extending from the first end to the second portion, the first portion of the first pin being a non-streamlined body, and the second portion of the first pin being a streamlined body.

[0038] 17. The heat sink according to clause 16, wherein the streamlined body is an airfoil.

[0039] 18. The heat sink according to clause 16, wherein the bluff body is elliptical or circular.

[0040] 19. The heat sink of clause 16, wherein the streamlined body is a shape having a drag coefficient below a predetermined threshold, and the bluff body is a shape having a drag coefficient equal to or above the predetermined threshold.

[0041] 20. The heat sink of clause 19, wherein the predetermined threshold is the drag coefficient of the ellipse or circle measured in the direction of flow along the length of the ellipse or circle.

[0042] 21. A method for forming a heat sink, the method comprising: forming a first portion of a pin fin, the first portion having a first cross-sectional shape taken along the length of the pin fin, the first cross-sectional shape being an ellipse; forming a second portion of the pin fin, the second portion having a second cross-sectional shape taken along the length of the pin fin, the second cross-sectional shape being an airfoil; and coupling the first portion of the pin fin to the second portion of the pin fin.

[0043] 22. The method of clause 21, wherein each of the first portion and the second portion of the pin-fin is formed by an additive manufacturing process, and the first portion and the second portion are coupled together by the additive manufacturing process.

[0044] 23. The method of clause 22, further comprising forming a substrate by the additive manufacturing process, wherein the first portion is coupled to the substrate by the additive manufacturing process.

[0045] 24. The method of clause 21, further comprising tempering an interface between the first portion and the second portion of the pin fin to remove a step defined by the interface.

[0046] 25. The method of clause 21, further comprising coupling the first end of the first portion to a substrate, wherein the second end of the first portion is coupled to the second portion.

[0047] Multiple embodiments of the present disclosure are described herein. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show the details of specific components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as restrictive, but only as a representative basis for teaching those skilled in the art to adopt these embodiments in various ways. As will be understood by those of ordinary skill in the art, the various features shown and described with reference to any one of the figures may be combined with the features shown in one or more other figures to produce embodiments that are not explicitly shown or described. The combination of features shown provides representative embodiments of typical applications. However, various combinations and modifications of features consistent with the teachings of the present disclosure may be desired for specific applications or implementations.

[0048] Unless the context clearly dictates otherwise, as used herein, "a", "an", and "the" refer to both singular and plural referents. For example, a "processor" programmed to perform various functions refers to one processor programmed to perform each and all functions, or more than one processor programmed to perform each of the various functions.

[0049] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms covered by the claims. The words used in the specification are descriptive words, not restrictive words, and it is understood that various changes can be made without departing from the spirit and scope of the present disclosure. As mentioned above, the features of various embodiments can be combined to form other embodiments of the present invention that may not be explicitly described or shown. Although various embodiments can be described as providing advantages or being superior to other embodiments or prior art implementations in terms of one or more desired features, it is recognized by those of ordinary skill in the art that one or more features or characteristics can be compromised to achieve the desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc. Therefore, in the case where any embodiment is described as being inferior to other embodiments or prior art implementations in terms of one or more features, these embodiments are not outside the scope of the present disclosure, but may be desirable for specific applications.

Claims

1. A radiator, comprising: substrate; as well as A plurality of pin fins, the plurality of pin fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, the first pin comprising a first end coupled to the base plate, a second end opposite the first end, a first portion and a second portion, the first portion extending from the first end to the second portion, the first portion of the first pin having a first cross-sectional shape taken along the length of the pin fin, the second portion of the first pin having a second cross-sectional shape taken along the length of the pin fin, the first cross-sectional shape being selected from a predetermined list including an ellipse, a circle, and an airfoil, and the second cross-sectional shape being selected from the predetermined list and being different from the first cross-sectional shape.

2. The heat sink according to claim 1, wherein: At least one of the first pin and the second pin includes a transition section at an interface between the first portion and the second portion, the transition section including a transition cross section that changes from the first cross-sectional shape to the second cross-sectional shape along the length of the pin fin.

3. The radiator according to claim 1 or 2, wherein: The plurality of pin-type fins are arranged in a plurality of rows of pin-type fins along a longitudinal direction, so that each row of pin-type fins is spaced apart from other rows of pin-type fins along a transverse direction, and the plurality of rows of pin-type fins are staggered so that a center of one of the plurality of pin-type fins is adjacent to a space between adjacent pin-type fins of an adjacent row in the transverse direction.

4. The radiator according to claim 1 or 2, wherein: The first portion accounts for at least 1% of the height of the pin fin.

5. The radiator according to claim 1 or 2, wherein: The second cross-sectional shape is an airfoil having a leading side and a trailing side, the leading side being larger than the trailing side.

6. The heat sink according to claim 5, wherein: The first cross-sectional shape is an ellipse or a circle.

7. A radiator assembly, comprising: substrate; a housing enclosing the substrate and containing a fluid; as well as A plurality of pin fins, the plurality of pin fins being coupled to the base plate, the plurality of pin fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, each of the plurality of pin fins comprising a first end coupled to the base plate, an opposite second end, a first portion and a second portion, each of the plurality of pin fins being spaced apart at the first end, the first portion extending from the first end to the second portion, the first portion having a first cross-sectional shape taken along the length of the pin fin, the second portion having a second cross-sectional shape taken along the length of the pin fin, the second cross-sectional shape being an airfoil, and the first cross-sectional shape not being an airfoil.

8. The heat sink assembly according to claim 7, wherein: The airfoil includes a front side and a rear side, the front side being larger than the rear side.

9. The radiator assembly of claim 8, further comprising a pump configured to direct a flow of fluid through the housing, wherein: The front side of the airfoil points upstream of the fluid flow.

10. The radiator assembly according to any one of claims 7 to 9, wherein: The first cross-sectional shape is an ellipse or a circle.

11. The radiator assembly according to any one of claims 7 to 9, wherein: Each pin fin of the plurality of pin fins includes a transition section at an interface between the first portion and the second portion, the transition section including a transition cross-section that changes from an elliptical shape or a circular shape to an airfoil shape along the length of the pin fin.

12. The radiator assembly according to any one of claims 7 to 9, wherein: The plurality of pin-type fins are arranged in a plurality of rows of pin-type fins along a longitudinal direction, so that each row of pin-type fins is spaced apart from other rows of pin-type fins along a transverse direction, and the plurality of rows of pin-type fins are staggered so that a center of one of the plurality of pin-type fins is adjacent to a space between adjacent pin-type fins of an adjacent row in the transverse direction.

13. The radiator assembly according to any one of claims 7 to 9, wherein: The first portion accounts for at least 1% of the height of the pin fin.

14. The heat sink assembly according to claim 13, wherein: The first portion accounts for 1% to 40% of the height of the pin fin.

15. The radiator assembly according to any one of claims 7 to 9, wherein: The different geometric features are cross-sectional shapes of the first pin and the second pin.

16. A heat sink, comprising: substrate; as well as A plurality of pin-type fins, the plurality of pin-type fins comprising a first pin and a second pin, the first pin and the second pin having at least one different geometric feature, each of the plurality of pin-type fins comprising a first end coupled to the base plate, a second end opposite to the first end, a first portion and a second portion, the first portion extending from the first end to the second portion, the first portion of the first pin being a non-streamline body, and the second portion of the first pin being a streamline body.

17. The heat sink according to claim 16, wherein: The streamlined body is an airfoil.

18. The heat sink according to claim 16 or 17, wherein: The non-streamlined body is elliptical or circular.

19. The heat sink according to claim 16 or 17, wherein: The streamlined body is a shape having a drag coefficient lower than a predetermined threshold, and the bluff body is a shape having a drag coefficient equal to or higher than the predetermined threshold.

20. The heat sink according to claim 19, wherein The predetermined threshold is the drag coefficient of the ellipse measured in the direction of flow along the length of the ellipse.

Images