Core for a delivery device and method of forming the same

Abstract

A core for a delivery device and a method of forming the same are provided. The core includes a structure having a plurality of connected cell lattices. At least one cell lattice has one or more side walls that are curved and define a portion of an internal passageway within and through the cell lattice. The one or more side walls define a plurality of apertures and include a taper disposed between at least some of the apertures. A dimple is defined along an outer surface of the cell lattice at the taper. The outer surface at least partially defines an external passageway that is sealed from the internal passageway by the one or more side walls of the cell lattice. The one or more side walls are configured to transfer one or more thermal energies from a first fluid or a component of the first fluid flowing in the internal passageway to a second fluid flowing in the external passageway without mixing the first fluid and the second fluid.

Description

TECHNICAL FIELD

[0001] The apparatus and methods described herein relate to devices that transfer heat between different fluids or filter particles. BACKGROUND

[0002] Cooling devices transfer heat from one fluid across or through a barrier to another fluid. One example of a cooling device is an Exhaust Gas Recirculation (EGR) cooler. The cooler transfers or absorbs heat from recirculated engine exhaust gases to a coolant, such as water, as the exhaust gases and coolant flow through the cooler. The cooler has a housing in which a core is disposed. The core has separate channels for the coolant and the exhaust gases. The core is designed to enable heat transfer from one fluid to another and / or filtration of components from one fluid through a barrier without the need to mix the two fluids. One problem with these coolers is the complexity of manufacturing and assembling the core geometry within the housing of the cooler. The fluid channels of the core can meander through the core in non-linear paths to promote fluid interaction with the walls for heat transfer and / or filtration without unduly increasing fluid flow resistance and / or pressure drop through the core. This complex geometry that provides tortuous flow channels while maintaining physical separation between the different fluids through the core can be constructed according to conventional processes such as casting.

[0003] Additive manufacturing can be used to three-dimensionally print or form complex core geometries. However, due to limitations of additive manufacturing techniques, printing complex repeating geometries often requires support structures to be formed under some of the downskin surfaces to maintain design integrity and structural integrity. Support structures are not desirable due to a variety of reasons, such as plugging flow channels, being difficult to remove or even if removed adversely affecting the core, and slowing the additive manufacturing process. To avoid forming support structures within the core geometry, one approach is to reduce the size of the repeating unit cells or lattices in the core. However, reducing the size of the unit cell lattices adversely increases flow resistance through the core, increases pressure drop through the core, reduces manufacturing speed, and increases manufacturing cost (e.g., more unit cell lattices need to be printed per given volume than if the unit cell lattices were larger). This can reduce throughput and transfer effectiveness. It would be desirable to have a system and method that is different from currently available systems and methods. SUMMARY

[0004] In one or more embodiments, a core is provided that includes a structure having a plurality of connected unit cells, and at least one of the plurality of connected unit cells has one or more sidewalls that are curved and have an inner surface that defines at least a portion of an internal passageway within the unit cell and through the unit cell. The one or more sidewalls of the unit cell define a plurality of apertures such that a first fluid can enter the unit cell through one of the apertures and can exit the unit cell through another of the apertures. The one or more sidewalls include a taper disposed between at least some of the apertures of the unit cell. The one or more sidewalls have an outer surface, and a dimple is defined along the outer surface on the taper. The one or more sidewalls have an edge that extends around the apertures of the unit cell. The edges of different unit cells are connected to one another, and the outer surface at least partially defines an external passageway that is sealed from the internal passageway by the one or more sidewalls of the unit cell. The external passageway is configured to enable a second fluid to flow therethrough. The one or more sidewalls of the unit cell are configured to transfer one or more portions of thermal energy from the first fluid or a component of the first fluid flowing in the internal passageway to the second fluid flowing in the external passageway without mixing the first fluid and the second fluid.

[0005] In one or more embodiments, a core is provided that includes a structure having a plurality of connected unit cells, and at least one of the plurality of connected unit cells has one or more sidewalls that are curved and have an inner surface that defines at least a portion of an internal passageway within the unit cell and through the unit cell. The one or more sidewalls of the unit cell define at least four apertures such that a first fluid can enter the unit cell through one of the apertures and can exit the unit cell through another of the apertures. A portion of the one or more sidewalls disposed between three of the apertures is triangularly shaped, and the three apertures are spaced 120 degrees apart from one another along a circumference of the unit cell. The one or more sidewalls have an edge that extends around the apertures of the unit cell. The edges of different unit cells are connected to one another to at least partially define an external passageway that is sealed from the internal passageway of the unit cell and the internal passageways of other unit cells by the one or more sidewalls of the unit cell. The external passageway is configured to enable a second fluid to flow therethrough. The one or more sidewalls of the unit cell are configured to transfer one or more portions of thermal energy from the first fluid or a component of the first fluid flowing in the internal passageway to the second fluid flowing in the external passageway without mixing the first fluid and the second fluid.

[0006] In one or more embodiments, a method (e.g., for forming a core) is provided. The method includes additively manufacturing a core by sequentially depositing layers of material, at least partially above each other, along a build direction to form a structure comprising a plurality of interconnecting unit lattices. At least one of the plurality of interconnecting unit lattices has one or more sidewalls that are curved and have an inner surface defining at least a portion of an internal passage within and through the unit lattice. The one or more sidewalls of the unit lattice define a plurality of orifices, such that a first fluid can enter the unit lattice through one of the orifices and exit the unit lattice through another of the orifices. The one or more sidewalls include cones disposed between at least some of the orifices of the unit lattice. The one or more sidewalls have an outer surface and define a recess along the outer surface at the cone. The one or more sidewalls have edges extending around the orifices of the unit lattice, and the edges of different unit lattices are connected to each other. The outer surface at least partially defines an external passage sealed within the internal passage by the one or more sidewalls of the unit lattice. The external passage is configured to allow a second fluid to flow through it. One or more sidewalls of the unit lattice are configured to transfer one or more portions of thermal energy from a first fluid or a component of the first fluid flowing in an internal passage to a second fluid flowing in an external passage without mixing the first fluid with the second fluid. Attached Figure Description

[0007] The subject matter of this application can be understood by referring to the following description of non-limiting embodiments, in which:

[0008] Figure 1 An example of a transfer device is shown;

[0009] Figure 2 It shows Figure 1 First cross-sectional view of the device shown;

[0010] Figure 3 A cross-sectional view of a portion of the core of the transfer device according to an embodiment is shown;

[0011] Figure 4 It shows Figure 1 Additional cross-sectional view of the device shown;

[0012] Figure 5 It shows Figure 1 Another cross-sectional view of the device shown;

[0013] Figure 6 It shows Figure 1 Another cross-sectional view of the device shown;

[0014] Figure 7 It shows along Figure 1 First cross-sectional view of the transmission device of line 7-7 in the middle;

[0015] Figure 8 A second cross-sectional view of the delivery device taken along a plane orthogonal to the line 7-7 in Figure 1

[0016] Figure 9 A second cross-sectional view of the delivery device taken along the line 13-13 shown in Figure 1

[0017] Figure 10 A perspective view of a core of the delivery device according to one embodiment;

[0018] Figure 11 A cross-sectional view of the core shown in Figure 10

[0019] Figure 12 A first cross-sectional view of the core taken along the line 12-12 shown in Figure 11

[0020] A second cross-sectional view of the core taken along the line 13-13 shown in Figure 13 Figure 11 A third cross-sectional view of the core taken along the line 14-14 shown in

[0021] Figure 14 Figure 11 A fourth cross-sectional view of the core taken along the line 15-15 shown in

[0022] Figure 15 A fifth cross-sectional view of the core taken along the line 16-16 shown in Figure 11

[0023] Figure 16 A cross-sectional view of the core shown in Figure 11

[0024] Figure 17 A flowchart illustrating one example of a method for creating a delivery device or component thereof. DETAILED DESCRIPTION

[0025] ​​​​​​​At least one embodiment described herein relates to a monolithic (e.g., unitary) transfer device that accommodates thermal expansion of the core through unique flexible membrane connections at the device inlet and outlet. Such flexible membranes can be more easily displaced than some known slip joints and / or seals without creating unacceptable stresses in the housing (e.g., shell) or core. The transfer device can force a cooling medium (e.g., coolant) through the core without the need to directly connect the housing to the core. The cooling medium can be forced to increase the pressure of the coolant at some locations by creating different sized volumes between (a) the membrane and (b) the housing and core (e.g., by additive manufacturing) to force the coolant through a greater portion of the core relative to some known coolers that use a slip seal between the core and the housing. The flexible membrane can be integrally formed with the core and the housing by additive manufacturing to provide a fully integrated wall to minimize or even eliminate coolant leakage between the core and the housing. Printing the housing and the core as one monolithic body can allow for strict control of the interface between the geometries of both the core and the housing.

[0026] Alternatively, the core and the housing described herein can be formed separately and then the core is placed into the housing. For example, the housing can be cast, additively manufactured, injection molded, etc. and the core can be additively manufactured and placed into the housing. The flexible membrane can be formed as part of the housing or the core or separately and then placed between the housing and the core. The housing and the core can then be welded together to form a fully integrated entity. Aspects and features of the design and manufacturing approach can be determined using the features disclosed herein.

[0027] The use of additive manufacturing for the flexible membrane and / or the core can enable the core to be fitted into a wide variety of application spaces. The housing can be made in a similar manner to avoid interfering with existing components to facilitate a style refresh.

[0028] Relative to some known EGR coolers, the device described herein can accommodate thermal cycling without a slip interface to maximize or extend the useful life of the device. In addition, because there are no moving or slip interfaces, the device can be able to withstand extreme temperature conditions without the need to use gaskets, O-rings, etc. for sealing. One of these conditions is the dry run condition of an engine where the engine exhaust flows through the device without a cooling medium flowing through the device. This can expose the device to temperatures in excess of 1,000 degrees Fahrenheit (or 540 degrees Celsius). In turn, extreme temperatures can cause extreme thermal expansion. The flexible membrane of the embodiments described herein can flex and accommodate the thermal expansion.

[0029] Other embodiments described herein relate to a core or wick of a transfer device. The wick can be defined or designed to have a repeating lattice of interconnected cells that define an internal passageway for one fluid through the cells and an external passageway for another fluid outside of the cells without physically mixing the two fluids with each other. For example, the internal passageway is not in fluid communication with the external passageway. The cells have sidewalls between the internal passageway and the external passageway that allow thermal energy (e.g., heat) to pass through the sidewalls from the hotter fluid to the cooler fluid. Optionally, the sidewalls can be defined or designed to allow one or more components to pass (e.g., filter) from the first fluid through the sidewalls into the second fluid. The first fluid and / or the second fluid can optionally include more than one fluid type, composition, or compound. For example, the first fluid can be a coolant introduced into the internal passageway of the core, and the second fluid can be a plurality of different fluids introduced into the external passageway. The plurality of different fluids can mix with each other within the core and transfer heat to the coolant through the thin sidewalls.

[0030] According to embodiments, the wick has a complex repeating geometry that separates the fluids and can be printed without forming support structures. The geometry of the wick allows for a relatively large, unsupported cell size to be selected. Larger cell sizes can provide lower flow resistance and pressure drop (e.g., higher fluid throughput) through the wick relative to smaller cell sizes. The cells are hollow, so increasing the size of the cells relative to smaller cells can actually reduce the amount of material deposited during the additive manufacturing process, thereby increasing the printing speed and reducing the printing and / or material costs.

[0031] The ability to additively manufacture the wick without support structures also enables the wick to be formed into a custom shape based on a particular application. In an EGR cooler, the wick can be printed to conform to the specific internal volume or form factor of the shell. Optionally, the wick can be integrally formed with the shell during a common additive manufacturing process to provide a monolithic EGR cooler. Integrally forming the wick with the shell eliminates the joint between the components, which can advantageously eliminate potential leak paths during use and operation of the EGR cooler.

[0032] Figure 1 An example of a transfer device 100 is shown. The device can be used to transfer energy or components between two media. For example, the device can transfer thermal energy (e.g., heat) from one fluid to another fluid (to cool one fluid) or can transfer components from one fluid to another fluid (to filter components from one fluid). The device includes a shell 102 in which an internal heat transfer wick and a flexible diaphragm are disposed (both in Figure 2The housing has a first inlet 110 to receive a first fluid 112 and a second inlet 114 to receive a second fluid 116. The first and second fluids can be gases and / or liquids. For example, the first fluid can be a coolant or cooling medium, such as a heat transfer fluid (e.g., water, refrigerant, other synthetic or natural fluids). The second fluid can be exhaust gas from an engine, or can be another liquid. The second fluid can be at a higher temperature than the first fluid prior to entering the device.

[0033] The housing also includes a first outlet 120 through which the first fluid is directed out of the housing and a second outlet 118 through which the second fluid is directed out of the housing. As described herein, the core has internal passages (as shown in Figure 2 and external passages (as shown in Figure 2 through which the first fluid flows from the first inlet through the core to the first outlet, and the second fluid flows from the second inlet through the core to the second outlet. As the first and second fluids flow through the respective internal and external passages, heat can be transferred from the second fluid to the first fluid (through or by the material forming the core). Alternatively, the material forming at least a portion of the core can filter one or more components from the second fluid to the first fluid (or from the first fluid to the second fluid). Alternatively, the first fluid can include multiple different fluids mixed together within the internal passages of the core. Alternatively, the second fluid can include multiple different fluids mixed together within the external passages of the core.

[0034] The internal passages can keep the first fluid separate from the second fluid, and the external passages can keep the second fluid separate from the first fluid. The internal passages can direct the first fluid from the first inlet to the first outlet. The first outlet can direct the first fluid (which has now been heated by the second fluid or has received one or more components from the second fluid) to a device or system that cools (or filters) the first fluid and returns the first fluid to the first inlet. The external passages can direct the second fluid from the second inlet to the second outlet. The second outlet can direct the second fluid (which has now been cooled by the first fluid or which has had one or more components removed and transferred to the first fluid) back to the engine (in an EGR engine) or another location.

[0035] Figure 2 A first cross-sectional view of the device is shown in Figure 1 A first cross-sectional view of the device is shown in Figure 2 The cross-section shown in Figure 1the plane of the housing and extending through the axis of the core. The internal heat transfer core 204 within the housing includes a single structure or web of material 201 shaped such that it forms a first internal passage 522 and a second internal passage 524. The first and second internal passages 522, 524 of the core are also referred to herein as the inner and outer passages, respectively. Alternatively, the core can be formed of multiple bodies or webs of material shaped such that they form the inner and outer passages.

[0036] The device includes a flexible membrane 206 that connects and extends from the core to an inner surface 208 of the housing. The membrane is flexible in that it can bend or otherwise change shape when subjected to more force or displacement than the housing and / or core (subjected to the same force or displacement). The membrane forms a flexible transition between (a) each of the first and second inlets of the housing and (b) the core. The flexible membrane forms a seal to prevent the first fluid flowing through the inner passage of the core from flowing into the outer passage of the core. The flexible membrane can accommodate different changes in size of the housing and core due to changes in heat. For example, the housing and core can expand different amounts or distances due to their different sizes (even when the housing and core are formed as a single piece and from the same material). Due to the different expansion of the housing and core, the flexible membrane can bend without tearing or otherwise breaking the seal between the housing and core. This allows the inner and outer passages of the core to remain separated.

[0037] Figure 3 A cross-sectional view of a portion of a core according to an embodiment is shown. Figure 3 The cross-section shown in FIG. 2 is along a plane parallel to and offset from the plane of the housing and extending through the axis of the core. The inner passage 522 is on one side of the body or web of material of the core, while the outer passage 524 is on the opposite side of the body or web of material of the core. For example, the body or web of material includes thin sidewalls 210 that separate the inner passage from the outer passage.

[0038] The sidewalls are part of unit cells 212 of the core that are repeating geometric shapes throughout the core. The unit cells are connected to each other. For example, the core is a structure having multiple connected unit cells. In one or more embodiments, the unit cells are shaped as substantially spherical shapes defined by the sidewalls, as shown in the circular cross-section in FIG. 2. The shape of the peripheral unit cells positioned along the cylindrical sides of the core can be distorted from spherical as needed to provide the desired overall size and / or shape of the core. In other embodiments, the unit cells can be other shapes. Other suitable shapes can include cubes, parallelepipeds, prisms, etc. The inner passage is defined within the unit cells and extends through the unit cells. The outer passage is outside of the unit cells, representing the unoccupied space between the unit cells. Figure 3 The cross-section shown in FIG. 2 is along a plane parallel to and offset from the plane of the housing and extending through the axis of the core. The inner passage 522 is on one side of the body or web of material of the core, while the outer passage 524 is on the opposite side of the body or web of material of the core. For example, the body or web of material includes thin sidewalls 210 that separate the inner passage from the outer passage. The sidewalls are part of unit cells 212 of the core that are repeating geometric shapes throughout the core. The unit cells are connected to each other. For example, the core is a structure having multiple connected unit cells. In one or more embodiments, the unit cells are shaped as substantially spherical shapes defined by the sidewalls, as shown in the circular cross-section in FIG. 2. The shape of the peripheral unit cells positioned along the cylindrical sides of the core can be distorted from spherical as needed to provide the desired overall size and / or shape of the core. In other embodiments, the unit cells can be other shapes. Other suitable shapes can include cubes, parallelepipeds, prisms, etc. The inner passage is defined within the unit cells and extends through the unit cells. The outer passage is outside of the unit cells, representing the unoccupied space between the unit cells.

[0039] As shown in Figure 3 , the internal passageways are separated from the external passageways by side walls. In Figure 3 , the internal passageways within the two unit cells are filled by diagonal lines to clearly show the distinction between the internal passageways and the external passageways that surround the internal passageways in the illustrated cross-sectional view. The side walls can be relatively thin. A suitable side wall thickness can be less than 3 millimeters (mm). The side walls of the unit cells are connected to one another at edges 806 (as shown in Figure 10 ) to fluidically connect the internal passageways throughout the core and to maintain the first and second fluids physically separated from one another. In one embodiment, heat can be transferred between the first fluid and the second fluid through the side walls without mixing any other portions of the first fluid and the second fluid together in the internal passageways or the external passageways. Alternatively, the side walls can include pores that filter one or more components from the second fluid to the first fluid (or from the first fluid to the second fluid) without mixing any other portions of the first fluid and the second fluid together in the internal passageways or the external passageways. In the illustrated embodiment, the fluid within the internal passageways is a gas and the fluid within the external passageways is a coolant. Alternatively, the gas in the internal passageways can be hot exhaust gas from an engine and the coolant in the external passageways can be water. As the water flows along the external passageways through the tortuous path between the unit cells, the water can absorb heat from the gas through the side walls of the unit cells. The water enters the core through the inlet openings 214 of the external passageways along the outer peripheral surface of the core.

[0040] Figure 4 、 Figure 5 and Figure 6 include other cross-sectional views of the device shown in Figure 1 . Figure 4 、 Figure 5 and Figure 6 are cross-sectional views taken along the same plane as the cross-sectional view of Figure 2 . The flexible diaphragm has a curved conical shape that extends inward from the inner surface of the housing to the core. This coning provides a conical transition between the housing and the core. The conical transition can be controlled to vary the length (e.g., the distance from the inner surface of the housing to the core) and / or the angle of intersection with the housing and the core so that the flexible diaphragm can be included within various shapes of the core and / or the housing. Because of the ability to customize the flexible diaphragm size and / or shape, a transfer device can be effectively sized and packaged for space-constrained applications. Although the housing is shown as cylindrical, the core and / or the housing can be another shape with the flexible diaphragm extending between the core and the housing and sealing the housing to the core. For example, the housing can be rectangular with the flexible diaphragm extending between the core and the housing and sealing the housing to the core.

[0041] In the illustrated embodiment, the flexible diaphragm is flat. For example, the diaphragm may have a smooth, tapered shape without undulations, waves, pits, protrusions, etc. Alternatively, the diaphragm may have an uneven surface with undulations, waves, pits, protrusions, etc.

[0042] As shown in the figure, the flexible diaphragm can be thinner than the outer shell. The inner surface 432 of the flexible diaphragm faces the core and is oriented away from the inner surface of the outer shell, in the portion between the second inlet and the second outlet of the outer shell. This inner surface of the flexible diaphragm can be oriented at an angle of less than 45 degrees to the inner surface of the outer shell. Alternatively, the inner surface can be oriented at an angle of less than 30 degrees or less than 15 degrees to the inner surface of the outer shell. The opposing outer surface 430 of the flexible diaphragm faces away from the core and may be oriented towards the inner surface of the outer shell in the portion between the second inlet and the second outlet. This outer surface of the flexible diaphragm can be oriented at an angle of greater than 45 degrees to the inner surface of the outer shell. Alternatively, the outer surface can be oriented at an angle of greater than 55 degrees or greater than 75 degrees to the inner surface of the outer shell.

[0043] Figure 7 The transmission device is shown along Figure 1 The first cross-sectional view of line 7-7 in the diagram. Figure 8 A second cross-sectional view of the transfer device is shown. Figure 8 The cross-sectional view in the middle is along with Figure 1 The line 7-7 is intercepted by a plane orthogonal to it. For example... Figure 1 As shown, the housing includes elongated notches 122 on opposite sides of the housing. The notches can extend in a direction from the second inlet to the second outlet. Figure 8 As shown, the notch can be positioned along the circumference of the housing, in the middle between the first inlet and the first outlet. For example, the notch can be on opposite sides of the housing. Alternatively, the notch can be located at another position and / or the housing can include more than two notches. The notch can reduce the distance or spatial clearance between the inner surface of the housing and the core. For example, the core can be positioned at a distance 434 further away from the notch and from the inner surface of the housing (e.g., Figure 5 and Figure 8 (as shown) and has a closer distance of 600 to the notch (as shown) Figure 7 and Figure 8 (As shown).

[0044] The smaller distance between the outer shell and the core at the notches helps to force the first fluid from the first inlet to the first outlet and out of the outlet. These notches reduce the flow rate of the first fluid through the first inlet to compress the first fluid and help force the first fluid to flow to the first outlet.

[0045] Figure 9 The transmission device is shown along Figure 1Another cross-sectional view of the line 7-7 is shown. In the embodiment shown here, the flexible septum is engaged with the inner surface of the housing having a rounded interface. For example, the flexible septum and / or the housing can form a fillet at one or both of the interface between the inner surface of the flexible septum and the inner surface of the housing and the interface between the outer surface of the flexible septum and the inner surface of the housing, rather than a straight line interface with a corner or interface. The flexible septum and / or the housing can have an inner fillet 726 and an outer fillet 728 on opposite sides of the interface between the flexible septum and the housing. These fillets can be rounded interfaces that increase the flexibility of the septum (as compared to an interface that does not include a rounded edge or fillet). The radius of curvature of the inner fillet can be smaller than the outer fillet, as shown. Figure 9 as shown.

[0046] Figure 10 A perspective view of a core of a delivery device according to one embodiment is shown. The unit cells of the core each have one or more curved sidewalls. The inner surface 800 of the one or more sidewalls defines at least a portion of an internal passageway that extends within and through the respective unit cell. The outer surface 802 of the one or more sidewalls defines at least a portion of an external passageway in the intervening space between the unit cells. The core has a height extending from a bottom end 810 to a top end 812 (opposite the bottom end). In the embodiment shown, the core is generally cylindrical to conform to the interior of the housing. For example, the core has an outer side 814 that is circumferential and extends from the top end to the bottom end. The surface along the outer side has grooves and undulations due to the curved sidewalls of the unit cells. The internal passageway through the unit cells causes a first fluid to flow generally along the vertical height of the core, for example, from the top end down and out through the bottom end. The external passageway causes a second fluid to flow laterally, radially, and circumferentially (as well as vertically). For example, the second fluid can enter the external passageway through the cylindrical outer side of the core, as shown. Figure 3 and Figure 8 as shown.

[0047] The unit cell lattices in the core are arranged in an array. In an embodiment, the lattices are arranged in multiple rows 816 stacked along the height of the core. The illustrated embodiment shows at least a portion of four rows 816a, 816b, 816c, 816d of unit cell lattices. Each row includes multiple unit cell lattices spaced apart from each other. The unit cell lattices in a row may be offset or shifted from the unit cell lattices in the row above or below. For example, a single unit cell lattice may be at least partially positioned above multiple unit cell lattices in that row. Due to the offset positions of the unit cell lattices, the first fluid is forced to meander through the internal pathways rather than undergoing essentially free fall through the core, thereby facilitating fluid-sidewall contact interactions. Fluid-sidewall interactions thus generate heat transfer and / or material transfer. In an embodiment, a given unit cell lattice in an intermediate row (e.g., 816b, 816c) is interconnected with unit cell lattices in the rows above and below. Alternatively, the unit cell lattices may not be directly fluidly connected to other unit cell lattices in the same row.

[0048] Except for the outer perimeter lattice being twisted to maintain the specified size and shape of the core, the unit lattices of the core can be identical in size and shape. The sidewalls of the unit lattices on the outer side of the core can be flatter (e.g., with less curvature) compared to the sidewall curvature along the inner unit lattice. The outer sidewalls close the internal pathways to maintain mechanical separation between the first and second fluids.

[0049] For example, Figure 10 The core shown has fewer than the number of unit cell lattices arranged in an array. Figure 8 The unit cell lattice of the core shown demonstrates that the number and size of the unit cell lattice can be selected based on application-specific parameters. Suitable parameters that can be considered may include heat transfer, fluid flow resistance, fluid pressure drop, etc. The core according to at least one embodiment is formed with a relatively large unit cell lattice size to reduce flow resistance and pressure drop and improve manufacturing efficiency (e.g., less material and printing) while providing sufficient fluid-sidewall interaction to achieve the desired transfer performance.

[0050] The sidewalls of the unit cell lattice define a plurality of orifices 804, which represent portions of the internal pathways through the unit cell lattice. For example, a first fluid can enter a corresponding unit cell lattice through one orifice and exit the unit cell lattice through another orifice. In one embodiment, the orifices of the unit cell lattice are connected to other unit cell lattices to fluidly connect the internal pathways through the core. Each orifice of the unit cell lattice can be fluidly connected to a different unit cell lattice. For example, the three orifices of the first unit cell lattice can be connected to a second, third, and fourth unit cell lattice, respectively. The sidewalls may have edges 806 extending around the lattice orifices. The edges of the different unit cell lattices are interconnected to interconnect the internal pathways and seal the internal pathways, isolating them from external pathways.

[0051] In embodiments, the edges of the connecting unit lattices are integrally connected to one another to define seamless interfaces between the unit lattices. For example, the core can be a single monolithic structure in which the unit lattices are interconnected at the seamless interfaces. The material composition of the core can be selected based on application-specific coefficients. For example, materials with good thermal conductivity, such as one or more metallic materials, can be used for heat exchange applications of the transfer device. Other types of materials, such as polymeric materials, ceramic materials, or composite materials, can be used to form the core for filtration applications in which at least one component of the first fluid or the second fluid is transferred to and / or through the sidewalls of the unit lattices.

[0052] According to at least one embodiment, the core is produced by additive manufacturing. The core is formed by sequentially depositing layers of build material at least partially on top of one another in a build direction to ultimately form the structure shown in Figure 10 The build material can be a powder that is deposited in a bed and then selectively heated to provide the specified location, size, and shape of each layer according to a design file. Alternatively, the build material can be a filament that is heated and selectively deposited by a movable

[0053] Figure 11 is a cross-sectional view of the core shown in Figure 10 Figure 11 The cross-sectional view in is taken along a plane that is orthogonal to the plane of the top end of the core in and the cross-sectional plane can bisect the core. Figure 10 Figure 11 shows an equalized view of two complete unit lattices (indicated by dashed circles) and multiple partial unit lattices. Figure 11 shows four apertures 804 defined by the sidewalls of each complete unit lattice. For example, two apertures are taken laterally in the upper right and lower left regions of the lattice, and two apertures are shown in the upper left and lower right regions that extend a certain depth into the core. In one embodiment, the unit lattice has a total of six apertures, with the other two omitted from due to the cross-sectional display. The six apertures provide flow channels to connect each unit lattice with six other unit lattices. In alternative embodiments, the unit lattices can have a different number of apertures. Figure 11

[0054] As shown in Figure 10 and Figure 11 ​​​As shown, the complete unit cells are spherical. For example, portions of the sidewalls of each unit cell between the apertures have a convex curvature relative to the center of the unit cell to define a sphere. Alternatively, the unit cells can be at least slightly elongated to define an ellipsoid or ovoid.

[0055] The unit cells in adjacent rows can be staggered. The internal passages can extend at an oblique angle relative to the row plane and the vertical height of the core, which facilitates the interaction of the fluid and the sidewalls. A line 821 extending from a center point 822 of a first unit cell to a center point 822 of a second unit cell connected to the first unit cell defines an angle 824 relative to the row plane (e.g., a horizontal plane) that is not less than 30 degrees and not more than 60 degrees. According to a more preferred range, the angle can be between 35 degrees and 45 degrees. More particularly, the angle can be between 40 degrees and 42 degrees. These angles can be selected to ensure sufficient printability and print quality of the additively manufactured core, and can also provide effective unit row packing.

[0056] The dimensions of the internal passages and the external passages vary along their lengths. Along the internal passages, the apertures define a narrowest dimension or flow restriction 818. The apertures of the unit cells can be larger than the narrowest dimension or flow restriction 820 in the external passages. The internal passages can occupy more space within the core than the external passages. The flow dimensions and the dimensions of the passages can vary depending on the type of fluid flowing through the passages and / or the desired transfer occurring between the fluids passing through the sidewalls. In one embodiment, a first fluid flowing through the internal passages is a hot gas, and a second fluid flowing through the external passages is a coolant designed to absorb heat from the gas. In alternative embodiments, the dimensions of the unit cells and / or the spacing between the unit cells can be varied such that the flow restriction in the external passages is larger than the flow restriction of the internal passages, and / or such that the external passages occupy more space in the core than the internal passages.

[0057] The unit cells include a tapered feature or cone 826 disposed between at least some of the apertures of the respective unit cell. The cone 826 projects toward the center point of the unit cell. The cone has an apex 830 between the center point of the cell and a portion of the sidewall at the base of the cone. The cone 826 can be hollow, and can define a dimple 828 along the outer surface of the cone portion of the sidewall. Some of the dimples of the cone are Figure 10 are shown in perspective view.

[0058] The cone is located at the base of the curved unit cell. For example, the cone can be disposed at the lowermost portion of the unit cell relative to the direction of gravity. In one embodiment, the cone is positioned along the centerline of the unit cell. When the unit cell is spherical or otherwise curved, the cone at the base or bottom of the unit cell enhances the printability of the core without the need for support structures. For example, as shown in Figure 11As shown, the base of the lattice is unsupported. Forming inflection points along the sidewalls at the base avoids the problems associated with printing relatively flat surfaces and / or curve nadirs without any support. The cones allow the unit cell lattice to remain approximately spherical without the need to print structures to support the building material islands during fabrication. The cones also prevent fluid from accumulating within the sidewalls of the unit cell lattice. For example, if the first fluid is a liquid, it will flow from the cone to the orifice surrounding it.

[0059] In one embodiment, the sidewalls of the unit cell lattice further include a second conical feature or cone 832 along the top of the unit cell lattice. The second cone is spaced apart from the first cone and disposed relative to the first cone between apertures in different groups of the unit cell lattice. The first cone is referred to herein as the lower cone 830, and the second cone as the upper cone 832. The upper cone is hollow and defines a recess 834. The upper cone projects relative to the core in the same direction as the lower cone. For example, both cones project toward the top of the core. The recess of the upper cone is defined along the inner surface of the sidewall. Optionally, the upper cone may be collinear with the lower cone. The upper cone may be included to improve the printability of the unit cell lattice in the core, similar to including the lower cone. The presence of the upper cone can eliminate relatively flat areas at the top of the curved unit cell lattice, areas that may be difficult to print reliably without underlying support.

[0060] Figure 12 The core is shown along Figure 11 The first cross-sectional view of line 12-12 shown. Figure 13 The core is shown along Figure 11 The second cross-sectional view of line 13-13 shown. Figure 14 The core is shown along Figure 11 The third cross-sectional view of line 14-14 shown. Figure 15 The core is shown along Figure 11 The fourth section view of line 15-15 shown. Figure 12 to Figure 15 The diagram in the image represents Figure 10 The images show top views of the core cut along different parallel planes. These views are taken when the core is additively manufactured from bottom to top. Figure 12 to Figure 15 The cross-sections shown can indicate different time stages of the build process. The core is formed using relatively thin sidewalls, which improves printing efficiency by limiting the amount of material to be printed and provides relatively large pathways inside and outside the lattice to limit fluid flow resistance and pressure drop.

[0061] Figure 12The illustrated core cross-section includes a circle 900 at the radial center and six semi-circles 902 that surround the central circle. These shapes represent portions of seven unit cells in the first row of the core. Three small circular openings 904 are arranged in a triangle around the central circle. The small openings represent portions of the dimples of the lower cones of the unit cells in the next row. The circular segments 906 that define the sidewalls of the small openings are Figure 11 portions of the lower cones.

[0062] Figure 13 The illustrated core cross-section includes three complete unit cells and three partial peripheral unit cells that are located Figure 12 in the second row above the unit cells in the first row. The unit cells in the second row are taken by the cut line 13-13. The three complete unit cells are spaced apart in a triangle. An outer passage is defined in the space between the unit cells in the second row. In one embodiment, each complete unit cell is built on top of and individually connected (through the edges of the apertures) to a plurality of unit cells in the lower row. Each complete unit cell can be disposed over portions of three lower unit cells.

[0063] Within the circular outline of each unit cell is a portion 910 of the sidewall disposed between the plurality of apertures. This portion defines the base or bottom of the unit cell and includes the lower cone. In Figure 13 the visible sidewall portion is generally triangular and is located between the three apertures. The three apertures are spaced 120 degrees apart from each other along the circumference of the unit cell. The lower cone can be located at the center and equidistant between the three apertures disposed in a triangle around the triangular portion. Each of the three apertures visible in each complete unit cell is fluidically connected to a different unit cell in the row below. For example, the apertures connect each unit cell to three lower unit cells, the respective unit cell extending at least partially over and overlapping the lower unit cells. When a first fluid flows through the inner passage of one respective unit cell, the first fluid is divided into branches that enter the three connected cells. Figure 13 Also illustrated is the top of the upper cone of the unit cell in the center.

[0064] Figure 14 The illustrated core cross-section includes three complete unit cells and three partial peripheral unit cells in a third row disposed on top of the unit cells in the second row. The arrangement of the unit cells in the third row is opposite (e.g., flipped relative to) the arrangement of the unit cells in the second row. For example, Figure 14 the three complete unit cells in the third row are arranged in a triangle similar to the triangle in Figure 13 but the triangle is flipped relative to Figure 13The triangular arrangement in is flipped 180 degrees. In one embodiment, the sidewall of a complete unit cell has three apertures fluidically connecting the respective unit cell to three different unit cells in the row above. For example, cell 212a in the second row is fluidically connected to three cells 212b, 212c, 212d in the third row. A complete unit cell according to the illustrated embodiment includes six apertures, including three apertures connecting to cells in the row below and three apertures connecting to cells in the row above. A first fluid can enter a unit cell through one or more apertures and can exit the unit cell through one or more other apertures.

[0065] Figure 15 is a plan view showing the top of the wick. The top of the wick includes a plurality of incomplete unit cells within the fourth row of the wick, the plurality of incomplete unit cells being located Figure 14 above the unit cells in the third row shown in cross-section in Figure 15 The arrangement and shape of the illustrated unit cells is similar to the unit cells in the first row shown in Figure 12 In one embodiment, each row of unit cells in the wick has one of three cell arrangements, and the rows are arranged in a repeating pattern along the height of the wick with the three cell arrangements alternating. In alternative embodiments, the unit cells can be arranged in a different number of repeating configurations.

[0066] Figure 16 is a cross-sectional view of the wick shown in Figure 11 where the enlarged area shows the upper cone 832 and the lower cone 826 according to an embodiment. In the illustrated embodiment, the lower cone is larger than the upper cone. For example, the base of the lower cone is wider than the base of the upper cone. The height of the lower cone from the base to the apex is also taller than the upper cone. The dimple 828 of the lower cone has a larger volume than the dimple 834 of the upper cone. The lower cone can be larger than the upper cone for printability considerations. In alternative embodiments, the upper and lower cones can have the same dimensions, or the upper cone can be larger than the lower cone.

[0067] The wick can be manufactured to have thin walls throughout. For example, the sidewalls can be less than 3 mm thick, even at the thickest portions. In one embodiment, the sidewall thickness is between 0.3 mm and 1.5 mm, inclusive. The aperture diameters can be significantly larger than the wall thickness. For example, the aperture diameters can be at least 3 mm. In one embodiment, the apertures can be at least ten times the wall thickness. The aperture diameters in such an embodiment can be up to 15 mm or more. Optionally, the thickness of the sidewalls can vary within this relatively narrow range. For example, the sidewalls along the lower cone can be thicker than the segments of the sidewalls extending from the lower cone. Optionally, the sidewalls along the upper cone can also be thicker than the segments of the sidewalls extending from the upper cone. The lower cone wall thickness can be larger than the upper cone wall thickness to support the larger size and greater curvature of the lower cone relative to the upper cone.

[0068] The thin wall enables the core to have a relatively large unit cell and pore. For example, for a complete cell that does not deform along the outer perimeter of the core, the unit cell size can be between 10 mm and 30 mm. For a spherical unit cell, the unit cell size refers to the inner diameter of the sidewall. In one embodiment, the unit cell size is about 20 mm. The cell size can be selected based on application-specific factors, such as fluid throughput and transfer characteristics, rather than printability factors. For example, known cores with repeating geometries either have a cell size that is significantly smaller to avoid the use of internal support structures within the core, or a larger cell size that includes internal support structures. Known cores do not include a large cell size without internal support structures.

[0069] Figure 17 A flowchart showing one example of a method 1000 for creating a transfer device or a component thereof is shown. The method can be used to create one or more embodiments of the transfer devices shown and / or described herein. The method can be performed by an additive manufacturing system, such as a three-dimensional printing system, that automatically prints the transfer device using an input file. Suitable input file formats can include STL, OBJ, AMF, 3MF, and the like. At step 1002, a layer of material is deposited onto a working surface. For example, a first layer of material for forming the transfer device can be printed from one or more filaments onto the working surface.

[0070] At step 1004, an additional layer of material is deposited onto the underlying material. The additional layer can be at least partially printed onto the layer of material deposited prior to the additional layer. At step 1006, it is determined whether the manufacturing of the transfer device is complete. If additional layers are to be deposited to complete the formation of the entire transfer device, the flow of the method can return to step 1004, whereby one or more additional layers can be deposited as described above (until the creation of the transfer device is complete). The layers can be at least partially deposited on top of one another to form the shape of the housing, flexible membrane, and core. By "at least partially" it is meant that an entire layer or a partial layer can be printed on top of an underlying layer. If the creation of the transfer device is complete, the flow of the method can continue to step 1008. At step 1008, the transfer device is removed from the working surface. The transfer device can then be used to transfer energy and / or components between fluids, as described above.

[0071] Optionally, the method can be used to form a component of a transfer device without forming at least one other component of the transfer device. For example, a core can be additively manufactured by sequentially depositing layers of material at least partially on top of one another along a build direction. The additive manufacturing can be performed by a three-dimensional printing system according to instructions in an input design file to produce a core according to embodiments described herein. For example, the method can be performed to print Figure 10 to Figure 16 the core shown.

[0072] Suitable processes include, for example, laser powder bed fusion, electron beam powder bed fusion, directed energy deposition (DED), and binder jetting. Laser powder bed fusion involves depositing a layer of powder on a build plate and using a ytterbium fiber laser to fuse selective portions of the powder using a scanned CAD pattern. Laser powder bed fusion can include selective laser melting or sintering. DED can be used to print at least a portion of the core and / or the delivery device using a very fast printing. For example, DED can be used to print a housing of the delivery device, which can then be fused directly with a flexible membrane connected to the core. Binder jetting makes parts by inserting metal powder and a polymer binding agent, where the binding agent is used to bind the particles and layers together without the use of laser heating. The material of the core can be selected based at least in part on the proposed additive manufacturing method. For example, binder jetting materials including a binder and a metal (or ceramic or cermet) can make a green body (e.g., a shape before sintering). The green body can be the final shape or can be shaped such that the sintered form is the final shape.

[0073] The core of the delivery device according to embodiments described herein is a three-dimensional structure having a lattice network of interconnected unit cells arranged in a regular repeating pattern. The properties and characteristics of the core can be selected based on application-specific parameters and desired functionality. For example, properties such as the shape of the individual (and repeating) cells within the structure can be selected to increase structural strength, thermal conductivity, flow or throughput through the core, surface area for fluid-membrane interaction, and the like. Optionally, the angle or slope of the sidewalls, the thickness of the sidewalls, the material composition of the sidewalls, the size of the sidewalls, and other characteristics of the sidewalls such as density, relative density, porosity, and the like can be selected to achieve desired strength, thermal conductivity, surface area, density, heat dissipation capacity, and the like. Relative density refers to the density of the material divided by the density of the core. Porosity represents a measure of the amount of void material (e.g., air) occupying the volume.

[0074] The properties of the entire core can be uniform, or they can vary with the core's height, radial thickness, etc., such that one or more properties in one region of the core can differ from those in another region. The shape, size, thickness, or spacing of the unit cell lattice throughout the core structure can vary to improve the performance characteristics of the heat exchanger. For example, the unit cell lattice size (e.g., diameter), orifice diameter, spacing between unit cells, ratio between the sizes of internal and external passages, and / or sidewall thickness can be selectively varied to control fluid flow, heat transfer, material transfer (e.g., filtration) into and / or through the sidewalls, and / or similar items. Changing flow resistance can help diffuse fluid to regions that receive less fluid flow under natural conditions than other regions. Unit cells closer to the radial center of the core can be smaller or more closely packed together than unit cells closer to the periphery or outer side of the core. Smaller sizes can increase flow resistance through internal and / or external passages located closer to the center, which can force more fluid to flow towards the periphery.

[0075] The core can be formed from at least one plastic, ceramic, and / or metallic material. Plastic materials may include or represent epoxy resins, vinyl esters, polyester thermosetting polymers (e.g., polyethylene terephthalate (PET)), polypropylene, etc. Ceramic materials may include or represent silica, alumina, silicon nitride, etc. Metallic materials may include or represent aluminum alloys, titanium alloys, cobalt-chromium alloys, stainless steel, nickel alloys, etc. The core can be a composite material, including mixtures of various materials such as plastic and ceramic, ceramic and metal (referred to as cermet composites), and / or plastic and metal. Optionally, the core can represent a reinforcing composite material, such as fiber-reinforced plastic. Fiber-reinforced plastic may include fibers embedded within a plastic matrix layer. Fibers may be carbon fibers, glass fibers, aramid fibers (e.g., ... Basalt fibers, naturally occurring bio-fibers such as bamboo, and / or similar materials can be used to reinforce composite materials. Reinforcing composites can be reinforced with materials of other shapes than fibers, such as powders or strips as described in other embodiments. The reinforcement can be embedded within any of the plastics listed above. Ceramic-ceramic composites can consist of any of the ceramics and metals listed above. For additive printing processes, materials can be provided in particulate form, such as powder, and the printing system can selectively fuse the particles together to form each layer of a solid building component.

[0076] An additive manufacturing system and / or post-printing instrumentation can be controlled to determine and provide a specific surface finish to the wick that influences how the wick interacts with a fluid flowing through the wick. For example, a rougher surface finish can increase flow resistance, increase heat transfer, and / or increase material transfer through the sidewall relative to a smoother surface finish. Optionally, the surface finish can vary across the wick to selectively control fluid flow and / or transfer conditions across the wick. Each aspect can be determined using the methods disclosed herein.

[0077] In one or more embodiments, a wick (e.g., a wick for a transfer device) includes a structure having a plurality of connected cell lattices, and at least one cell lattice of the plurality of connected cell lattices has one or more sidewalls that are curved and have an inner surface that defines at least a portion of an internal passageway within and through the cell lattice. The one or more sidewalls of the cell lattice define a plurality of apertures such that a first fluid can enter the cell lattice through one of the apertures and can exit the cell lattice through another of the apertures. The one or more sidewalls include a taper disposed between at least some of the apertures of the cell lattice. The one or more sidewalls have an outer surface and define a dimple along the outer surface at the taper. The one or more sidewalls have an edge that extends around the apertures of the cell lattice. The edges of different cell lattices are connected to one another, and the outer surface at least partially defines an external passageway that is sealed from the internal passageway by the one or more sidewalls of the cell lattices. The external passageway is configured to enable a second fluid to flow therethrough. The one or more sidewalls of the cell lattice are configured to transfer one or more portions of thermal energy from the first fluid or a component of the first fluid flowing in the internal passageway to the second fluid flowing in the external passageway without mixing the first fluid and the second fluid.

[0078] Optionally, the cone protrudes towards a center point of the unit cell. Optionally, the unit cell defines at least three apertures and the cone is located equidistant from the at least three apertures. The cone can be located equidistant from three apertures that are spaced 120 degrees apart along a circumference of the unit cell. Optionally, the unit cell has a spherical shape defined by portions of one or more sidewalls of the unit cell that are located between the apertures and spaced apart from the cone. A wall thickness of the sidewalls of the unit cell can be no less than 0.3 mm and no greater than 1.5 mm. An aperture diameter of the unit cell can be at least ten times a wall thickness of one or more sidewalls of the unit cell. Optionally, the aperture diameter of the unit cell is greater than a diameter of the outer passageway. Optionally, the core is a single monolithic body, the plurality of unit cells being connected together at seamless interfaces. The structure can be composed of a metallic material, a polymeric material, or both a metallic material and a polymeric material. Optionally, the unit cells are arranged in rows that are at least partially stacked above one another, and a line extending from a center point of one unit cell in a first row to a center point of another unit cell in a second row defines an angle no less than 30 degrees and no greater than 60 degrees relative to a plane of the first row.

[0079] Optionally, the cone is a first cone and the one or more sidewalls of the unit cell include a second cone disposed between a set of apertures of the unit cell that is different from the apertures between which the first cone is disposed. The first cone and the second cone protrude in a common direction. The structure has a height extending from a bottom end of the structure to a top end of the structure, and the first cone of the unit cell is disposed below the second cone of the unit cell along the height. The first cone can have a size that is greater than a size of the second cone.

[0080] In one or more embodiments, a core (e.g., for a delivery device) includes a structure having a plurality of cell lattices, and at least one cell lattice of the plurality of cell lattices has one or more sidewalls that are curved and have an inner surface that defines at least a portion of an interior passageway within and through the cell lattice. The one or more sidewalls of the cell lattice define at least four apertures such that a first fluid can enter the cell lattice through one of the apertures and can exit the cell lattice through another of the apertures. A portion of the one or more sidewalls disposed between three of the apertures is triangularly shaped, and the three apertures are spaced 120 degrees apart from each other along a circumference of the cell lattice. The one or more sidewalls have edges that extend around the apertures of the cell lattice. The edges of different cell lattices are connected to each other to at least partially define exterior passageways that are sealed from the interior passageways of the cell lattices and the interior passageways of other cell lattices. The exterior passageways are configured to enable a second fluid to flow therethrough. The one or more sidewalls of the cell lattice are configured to transfer one or more portions of thermal energy from the first fluid or a component of the first fluid flowing in the interior passageway to the second fluid flowing in the exterior passageway without mixing the first fluid with the second fluid.

[0081] Optionally, the portion of the one or more sidewalls having a triangular shape includes a taper. The one or more sidewalls have an outer surface and define a recess along the outer surface at the taper. The taper can project toward a center point of the cell lattice. Optionally, the core is a single monolithic body, and the plurality of cell lattices are connected together at seamless interfaces. Optionally, the cell lattices are arranged in rows that are at least partially stacked above each other. A line extending from a center point of one cell lattice in a first row to a center point of another cell lattice in a second row can define an angle relative to a plane of the first row that is not less than 30 degrees and not more than 60 degrees. Optionally, the cell lattices define not more than or less than six apertures.

[0082] In one or more embodiments, a method for forming a core of a delivery device includes additively manufacturing the core by sequentially depositing layers of material at least partially over one another in a build direction to form a structure comprised of a plurality of connected unit cells. At least one of the plurality of connected unit cells has one or more sidewalls that are curved and have an inner surface that defines at least a portion of an internal passageway within and through the unit cell. The one or more sidewalls of the unit cell define a plurality of apertures such that a first fluid can enter the unit cell through one of the apertures and can exit the unit cell through another of the apertures. The one or more sidewalls include a taper disposed between at least some of the apertures of the unit cell. The one or more sidewalls have an outer surface and define a dimple along the outer surface at the taper. The one or more sidewalls have an edge that extends around the apertures of the unit cell and edges of different unit cells are connected to one another. The outer surface at least partially defines an external passageway that is sealed from the internal passageway by the one or more sidewalls of the unit cell. The external passageway is configured to enable a second fluid to flow therethrough. The one or more sidewalls of the unit cell can transfer one or more portions of thermal energy from the first fluid or a component of the first fluid flowing in the internal passageway to the second fluid flowing in the external passageway without mixing the first fluid with the second fluid.

[0083] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. "Optional" or "optional" means that the subsequently described event or circumstance can or can not occur, and that the description can include instances where the event occurs and instances where it does not. As used throughout the description and claims, approximate language can apply to modify any quantitative representation that can allow for variation without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about," "substantially," and "approximately,” can not be limited to the precise value specified. In at least some instances, approximate language can correspond to the precision of an instrument used to measure the numerical value. Here and throughout the specification and claims, range limitations can be combined and / or interchanged, such ranges can be identified and include all the sub-ranges contained therein unless context or language indicates otherwise.

[0084] This written description uses examples to disclose embodiments, including the best mode, and also to enable any person skilled in the art to practice the embodiments, including making and using any devices or systems and performing any incorporated methods. The claims define the scope of the disclosure of which patent can be granted, and include other examples that occur to persons of ordinary skill in the art. If other examples have the same structure as the literal language of the claims, or if they include equivalent structure that does not materially differ from the literal language of the claims, then these other examples are intended to fall within the scope of the claims.

Claims

1. A core comprising: a structure having a plurality of cell lattices, at least one cell lattice of the plurality of cell lattices having one or more side walls, the side walls being curved and having an inner surface defining at least a portion of an internal passageway within the cell lattice and through the cell lattice, the one or more side walls of the cell lattice defining a plurality of apertures such that a first fluid can enter the cell lattice through one of the apertures and can exit the cell lattice through another of the apertures, the one or more side walls including a taper disposed between at least some of the apertures of the cell lattice, the one or more side walls having an outer surface and defining a dimple along the outer surface on the taper, and the one or more side walls having edges extending around the apertures of the cell lattice, wherein the edges of different cell lattices are connected to one another and the outer surface at least partially defines an external passageway sealed from the internal passageway by the one or more side walls of the cell lattice, the external passageway configured to enable a second fluid to flow therethrough, the one or more side walls of the cell lattice configured to transfer one or more of thermal energy, a component of the first fluid, or a component of the second fluid through the one or more side walls without mixing the first fluid with the second fluid.

2. The core of claim 1, wherein, the taper projects toward a center point of the cell lattice.

3. The core of claim 1, wherein, the cell lattice defines at least three apertures and the taper is located equidistant from the at least three apertures.

4. The core of claim 3, wherein, the taper is located equidistant from three of the apertures spaced 120 degrees apart from one another along a circumference of the cell lattice.

5. The core of claim 1, wherein, the cell lattice has a spherical shape defined between the apertures by portions of the one or more side walls of the cell lattice and spaced apart from the taper.

6. The core of claim 1, wherein, a wall thickness of the side walls of the cell lattice is not less than 0.3 mm and not greater than 1.5 mm.

7. The core of claim 1, wherein, a diameter of the apertures of the cell lattice is at least ten times a wall thickness of the one or more side walls of the cell lattice.

8. The core of claim 1, wherein, the core is a single monolithic body, the plurality of cell lattices being connected together at seamless interfaces.

9. The core of claim 1, wherein, the structure is composed of one or more of a metallic material or a polymeric material.

10. The core of claim 1, wherein, the cell lattices are arranged in rows at least partially stacked above one another, and a line extending from a center point of one cell lattice in a first row to a center point of another cell lattice in a second row defines an angle relative to a plane of the first row that is not less than 30 degrees and not greater than 60 degrees.

11. The core of claim 1, wherein, a diameter of the apertures of the cell lattice is greater than a diameter of the external passageway.

12. The core of claim 1, wherein, the taper is a first taper, the one or more side walls of the cell lattice including a second taper disposed between a set of apertures of the cell lattice different from the apertures between which the first taper is disposed; the first taper and the second taper projecting in a common direction.

13. The core of claim 12, wherein, The structure has a height extending from a bottom end of the structure to a top end of the structure, the first pyramid of the unit cell is disposed below the second pyramid of the unit cell along the height, the first pyramid has a size that is greater than a size of the second pyramid.

14. A core comprising: a structure having a plurality of connected unit cells, at least one unit cell of the plurality of connected unit cells having one or more sidewalls, the sidewalls being curved and having an inner surface that defines at least a portion of an interior passageway within the unit cell and through the unit cell, the one or more sidewalls of the unit cell defining at least four apertures such that a first fluid can enter the unit cell through one of the apertures and can exit the unit cell through another of the apertures, a portion of the one or more sidewalls disposed between three of the apertures having a triangular shape and including a pyramid projecting toward a center point of the unit cell, and the one or more sidewalls having edges extending around the apertures of the unit cell, wherein the edges of different unit cells are connected to one another to at least partially define an exterior passageway sealed from the interior passageway of the unit cell and the interior passageways of other unit cells by the one or more sidewalls of the unit cell, the exterior passageway configured to enable a second fluid to flow therethrough, the one or more sidewalls of the unit cell configured to transfer one or more of thermal energy, a component of the first fluid, or a component of the second fluid through the one or more sidewalls without mixing the first fluid with the second fluid.

15. The core of claim 14, wherein, the one or more sidewalls having an outer surface and defining a dimple along the outer surface on the pyramid.

16. The core of claim 14, wherein, the pyramid is a first pyramid, the one or more sidewalls of the unit cell including a second pyramid spaced apart from the first pyramid, the first pyramid and the second pyramid projecting in a common direction.

17. The core of claim 14, wherein, the core is a single monolithic body, the plurality of unit cells being connected together at seamless interfaces.

18. The core of claim 14, wherein, the unit cells are arranged in rows at least partially stacked above one another, and a line extending from a center point of one unit cell in a first row to a center point of another unit cell in a second row defines an angle relative to a plane of the first row that is not less than 30 degrees and not greater than 60 degrees.

19. The core of claim 14, wherein, the unit cell defines not more than or less than six apertures.

20. A method for forming a core comprising: A core is additively manufactured by sequentially depositing layers of material at least partially on top of one another along a build direction to form a structure comprised of a plurality of connected unit cells, wherein at least one unit cell of the plurality of connected unit cells has one or more sidewalls that are curved and have an inner surface that defines at least a portion of an internal passageway within the unit cell and through the unit cell, the one or more sidewalls of the unit cell define a plurality of apertures such that a first fluid can enter the unit cell through one of the apertures and can exit the unit cell through another of the apertures, the one or more sidewalls include a taper disposed between at least some of the apertures of the unit cell, the one or more sidewalls have an outer surface, a dimple is defined along the outer surface on the taper, and the one or more sidewalls have an edge that extends around the apertures of the unit cell, wherein the edges of different unit cells are connected to one another, the outer surface at least partially defines an external passageway that is sealed from the internal passageway by the one or more sidewalls of the unit cell, the external passageway is configured to enable a second fluid to flow therethrough, the one or more sidewalls of the unit cell are configured to transfer one or more of thermal energy, a component of the first fluid, or a component of the second fluid through the one or more sidewalls without mixing the first fluid with the second fluid.

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