EP4652359A1

EP4652359A1 - Honeycomb heater body

Info

Publication number: EP4652359A1
Application number: EP24704661.8A
Authority: EP
Inventors: Dmitrii ARTEMIEV; Varvara Manuilova; Min Shen
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2023-01-18
Filing date: 2024-01-08
Publication date: 2025-11-26
Also published as: WO2024155463A1; CN120476248A

Abstract

An electrical heater body, comprising an outer periphery, a plurality of slots, a plurality of core segments, and a plurality of end regions, is disclosed. Each slot extends from the outer periphery to a terminal end within the electrical heater body. Each core segment is defined between a different pair of adjacent slots. Each end region is between one of the terminal ends of the slots and the outer periphery. Each pair of adjacent core segments is connected by one of the end regions. The electrical heater body is shaped as an array of intersecting walls. A first group of intersecting walls extend in a primary direction parallel to the plurality of slots. A second group of intersecting walls intersect the first group at a plurality of intersection angles. At least a portion of the intersection angles in each of the core segments varies along the primary direction.

Description

HONEYCOMB HEATER BODY

Cross Reference to Related Application

[0001] This application claims the benefit of priority under 35 U.S. C. § 119 of U.S. Provisional Application Serial No. 63/439693, filed on January 18, 2023, the content of which is relied upon and incorporated herein by reference in its entirety.

Field of the Disclosure

[0002] This disclosure relates to heater assemblies that comprise honeycomb bodies, in particular honeycomb bodies having serpentine current-carrying paths defined by slots extending into the honeycomb bodies, and exhaust aftertreatment systems comprising such heater assemblies.

Background

[0003] Pollution abatement systems, such as exhaust aftertreatment systems coupled to an internal combustion engine, e.g., that of an automobile or other vehicle, may include heater assemblies to provide supplemental heat in order to assist in operation of the system. For example, catalyst materials used in catalytic converters or other catalyst-containing aftertreatment components may require a sufficient minimum temperature to initiate catalytic reaction, which may be referred to as catalyst light off.

[0004] In the case of internal combustion engines, heat can also be supplied from the exhaust flow itself, but it may take some amount of time for the exhaust temperature to raise sufficient each time the engine is first turned on, which may be referred to as cold start of the engine. Even if the system is arranged for the exhaust flow to heat the catalyst to its light off temperature within a few seconds, these first few seconds after a cold start can contribute significantly to the overall emissions of the engine, and may even constitute the majority of emissions of the engine. Accordingly, supplemental heat provided by a heater assembly can considerably reduce the time it takes for the catalyst light off temperature is achieved, thereby reducing emissions, particularly after cold start events. Summary of the Disclosure

[0005] Generally, in one aspect, an electrical heater body is disclosed. The electrical heater body comprises an outer periphery.

[0006] The electrical heater body further comprises a plurality of slots. Each slot extends from the outer periphery to a terminal end within the electrical heater body.

[0007] The electrical heater body further comprises a plurality of core segments. The plurality of core segments comprises an electrically conductive material. Each core segment is defined between a different pair of adjacent slots. The electrically conductive material is shaped as an array of intersecting walls defining a honeycomb pattern of cells.

[0008] The electrical heater body further comprises a plurality of end regions. The plurality of end regions comprises the electrically conductive material. Each end region is between a respective one of the terminal ends of the slots and the outer periphery. Each pair of adjacent core segments is connected by a corresponding one of the plurality of end regions.

[0009] The plurality of slots disconnects each pair of adjacent core segments from each other to create an electrically conductive serpentine path. A first group of the array of intersecting walls extend in a primary direction parallel to the plurality of slots. A second group of the array of intersecting walls intersect the first group of walls at a plurality of intersection angles. At least a portion of the plurality of intersection angles in each of the plurality of core segments varies along the primary direction.

[0010] In embodiments, each core segment of the plurality of core segments comprises a square cell portion. Each of the plurality of intersection angles within the square cell portion is substantially ninety degrees. Each core segment of the plurality of core segments further comprises a first skewed cell portion coupling the square cell portion to one of the plurality of end regions. Each of the plurality of intersection angles within the first skewed cell portion is greater than ninety degrees. Each core segment of the plurality of core segments further comprises a second skewed cell portion coupling the square cell portion to another of the plurality of end regions. Each of the plurality of intersection angles within the second skewed cell portion is greater than ninety degrees.

[0011] In embodiments, within the first skewed cell portion, the plurality of intersection angles incrementally increases in size along the primary direction from the square cell portion towards the first end region. In further embodiments, within the second skewed cell portion, the plurality of intersection angles incrementally decreases in size along the primary direction from the second end region towards the square cell portion.

[0012] In embodiments, each of the plurality of core segments has an equal skew ratio. The skew ratio of one of the plurality of core segments may be defined as a ratio of a number of cells within the first skewed cell portion and the second skewed cell portion to a number of cells within the square cell portion. In further embodiments, each of the plurality of core segments has a skew ratio of approximately fifteen percent.

[0013] In embodiments, a portion of the honeycomb pattern of cells within the plurality of end regions are substantially trapezoidal.

[0014] In embodiments, the electrically conductive material is a metal, a metal alloy, or metal composite. In further embodiments, the electrically conductive material is a nickelchromium-based superalloy.

[0015] In embodiments, the electrical heater body is formed via additive manufacturing or extrusion.

[0016] In embodiments, the terminal end of each of the plurality of slots is rounded.

[0017] In embodiments, an electrical heater assembly is provided. The electrically heater assembly comprises the electrical heater body. The electrical heater body is coupled to a pair of electrodes at opposite ends of the electrically conductive serpentine path.

[0018] Generally, in another aspect, an electrical heater body is disclosed. The electrical heater body comprises an outer periphery.

[0019] The electrical heater body further comprises a plurality of slots. Each slot extends from the outer periphery to a terminal end within the electrical heater body.

[0020] The electrical heater body further comprises a plurality of core segments. The plurality of core segments comprises an electrically conductive material. Each core segment is defined between a different pair of adjacent slots. The electrically conductive material is shaped as an array of intersecting walls defining a honeycomb pattern of cells.

[0021] The electrical heater body further comprises a plurality of end regions. The plurality of end regions comprises the electrically conductive material. Each end region is between a respective one of the terminal ends of the slots and the outer periphery. Each pair of adjacent core segments is connected by a corresponding one of the plurality of end regions. [0022] The plurality of slots disconnects each pair of adjacent core segments from each other to create an electrically conductive serpentine path. At least a portion of the honeycomb pattern of cells varies in cross-sectional area along a primary direction parallel to the plurality of slots. [0023] In embodiments, each core segment of the plurality of core segments comprises a square cell portion. A square cross-sectional area of each cell of the honeycomb pattern of cells within the square cell portion is substantially equal. Each core segment of the plurality of core segments further comprises a first skewed cell portion coupling the square cell portion to a first end region of the plurality of end regions. A first skewed cross-sectional area of each cell of the honeycomb pattern of cells within the first skewed cell portion is greater than the square cross-sectional area. Each core segment of the plurality of core segments further comprises a second skewed cell portion coupling the square cell portion to a second end region of the plurality of end regions. A second skewed cross-sectional area of each cell of the honeycomb pattern of cells within the first skewed cell portion is greater than the square cross-sectional area.

[0024] In embodiments, within the first skewed cell portion, the cross-sectional area of each cell incrementally increases along the primary direction from the square cell portion towards the first end region. In further embodiments, within the second skewed cell portion, the cross- sectional area of each cell incrementally decreases along the primary direction from the second end region towards the square cell portion.

[0025] In embodiments, the terminal end of each of the plurality of slots is rounded. [0026] In embodiments, each of the plurality of core segments has an equal skew ratio. [0027] Generally, in another aspect, an electrical heater body is disclosed. The electrical heater body comprises an outer periphery.

[0028] The electrical heater body further comprises a plurality of slots. Each slot extends from the outer periphery to a terminal end within the electrical heater body.

[0029] The electrical heater body further comprises a plurality of core segments. The plurality of core segments comprises an electrically conductive material. Each core segment is defined between a different pair of adjacent slots. The electrically conductive material is shaped as an array of intersecting walls defining a honeycomb pattern of cells.

[0030] The electrical heater body further comprises a plurality of end regions. The plurality of end regions comprises the electrically conductive material. Each end region is between a respective one of the terminal ends of the slots and the outer periphery. Each pair of adjacent core segments is connected by a corresponding one of the plurality of end regions.

[0031] The plurality of slots disconnects each pair of adjacent core segments from each other to create an electrically conductive serpentine path. A first group of the array of intersecting walls extend in the primary direction parallel to the plurality of slots. A second group of the array of intersecting walls intersect the first group of walls at a plurality of intersection angles. Each of a plurality of electrical conduction paths defined from the first group of the array of intersection walls to one of the slots incrementally varies along the primary direction.

[0032] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description, serve to explain principles and operation of the various embodiments.

Brief Description of the Drawings

[0033] FIG. 1 is cross-sectional side view of an exhaust aftertreatment assembly according to embodiments disclosed herein.

[0034] FIG. 2 is a front view of an electrical heater assembly having a serpentine design formed by a plurality of electrically insulating slots, a plurality of core segments between each pair of adjacent slots, and an end region proximate to a terminal end of each slot and connecting adjacent core segments together, according to embodiments disclosed herein.

[0035] FIG. 3 shows a portion of a heater body, according to embodiments disclosed herein. [0036] FIG. 4 is a front view of a portion of a heater body having a square cell design, according to embodiments disclosed herein.

[0037] FIG. 5 is a front view of a portion of a heater body having a skewed cell design, according to embodiments disclosed herein.

[0038] FIG. 6 is a front view of a portion of a heater body having a skewed cell design illustrating intersection angles and electrical conduction paths formed by an array of intersecting walls, according to embodiments disclosed herein. [0039] FIG. 7 is a front view of a portion of a heater body having a skewed cell design and rounded slot terminal ends, according to embodiments disclosed herein.

[0040] FIG. 8A is a power density model illustrating cold zones in a portion of a heater body having a square cell design, according to embodiments disclosed herein.

[0041] FIG. 8B is a power density model illustrating warmer zones in a portion of a heater body having a skewed cell design, according to embodiments disclosed herein.

[0042] FIG. 9A is a peak power consumption model focusing on a slot terminal end adjacent portion of a vertical wall of a heater body having a square cell design, according to embodiments disclosed herein.

[0043] FIG. 9B is a peak power consumption model focusing on a slot terminal end adjacent portion of a vertical wall of a heater body having a skewed cell design, according to embodiments disclosed herein.

[0044] FIG. 10A is a front view of a model of a heater body, according to embodiments disclosed herein.

[0045] FIG. 10B is a temperature profile of the heater body of FIG. 10A, according to embodiments disclosed herein.

[0046] FIG. 11A is a front view of a model of a heater body where each core segment has an equal skew ratio, according to embodiments disclosed herein.

[0047] FIG. 1 IB is a temperature profile of the heater body of FIG. 11A, according to embodiments disclosed herein.

[0048] FIG. 12 is a front view of a model of a heater body having a square cell design and a plurality of V-shaped features for hot spot mitigation, according to embodiments disclosed herein.

[0049] FIG. 13 is a plot comparing temperature over time of two heater bodies having squared and skewed designs, respectively, according to embodiments disclosed herein.

[0050] FIG. 14 is a plot comparing gas temperature uniformity factor over time of two heater bodies having squared and skewed designs, respectively, according to embodiments disclosed herein.

[0051] FIG. 15A is a gas temperature distribution profile based on the heater body shown in FIG. 12, according to embodiments disclosed herein.

[0052] FIG. 15B is a gas temperature distribution profile based on the heater body shown in FIG. 1 IB, according to embodiments disclosed herein. Detailed Description of Embodiments

[0053] Reference will now be made in detail to exemplary embodiments which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the exemplary embodiments.

[0054] Numerical values, including endpoints of ranges, can be expressed herein as approximations preceded by the term “about,” “approximately,” or the like. In such cases, other embodiments include the particular numerical values. Regardless of whether a numerical value is expressed as an approximation, two embodiments are included in this disclosure: one expressed as an approximation, and another not expressed as an approximation. It will be further understood that an endpoint of each range is significant both in relation to another endpoint, and independently of another endpoint.

[0055] Modifications of the disclosure will occur to those skilled in the art and to those who make or use the disclosure. Therefore, it is understood that the embodiments shown in the drawings and described herein are merely for illustrative purposes and not intended to limit the scope of the disclosure, which is defined by the following claims, as interpreted according to the principles of patent law, including the doctrine of equivalents.

[0056] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. When the term “about” is used in describing a value or an end-point of a range, the disclosure should be understood to also include the specific value or end-point referred to.

[0057] Directional terms as used herein — for example up, down, right, left, front, back, top, bottom — are made only with reference to the figures as drawn and are not intended to imply absolute orientation. As used herein, the term “radial” refers to directions perpendicular to the indicated axial direction that extend from the center point (e.g., see center axis C in FIG. 2) of a shape to or toward the outer perimeter of the shape, regardless of the shape of the component or feature with respect to which the radial direction is used. Similarly, the term “diameter” as used herein is not limited to circular shapes, but instead refers to the longest dimension of a component that passes through the center point (center axis) of the shape of that component. For example, a radial distance of a square-shaped component can be measured as the straight- line distance from the center point (center axis) to an intersection with one of the walls of the square, while the diameter of a square refers to the longest dimension diagonally across the square. The terms “cross-sectional width” or “cross-sectional dimension” may also be used to refer to these directions perpendicular to the axial direction.

[0058] Fluid treatment systems, such as automobile exhaust aftertreatment systems or other pollution abatement systems, can comprise a supplemental source of heat to facilitate operation, such as faster catalyst light-off in the case of catalyst-containing systems. For example, heat can be supplied by an electric heater (e.g., arranged to transfer heat to the catalyst material) or an electrically heated catalyst substrate (e.g., an electrically conductive substrate that is carrying a catalytic material). For example, a heater can be arranged upstream of a catalyst substrate and heat the catalyst by providing heat to the flow of exhaust (or supplemental air flow), which in turn heats the catalyst. Aftertreatment systems employing supplemental heat can be provided to reduce emissions in gasoline, diesel, and/or hybrid vehicles to assist in ensuring fast and consistent light-off of the catalyst during operation of the corresponding engine, particularly after cold-start of the engine.

[0059] Referring now to FIG. 1, a fluid treatment assembly 10 is illustrated, e.g., which can be arranged as part of an exhaust system of automobile. The fluid treatment assembly 10 comprises an outer housing 12 (which may be alternatively referred to as a “can”), such as formed in a generally tubular shape (e.g., a hollow tube) from metal or suitable material. The outer housing 12 has an inlet 14, e.g., which can be connected in fluid communication with the exhaust manifold of an internal combustion engine, and an outlet 16, e.g., which can be connected in fluid communication with a tail pipe of an automobile.

[0060] Exhaust from an engine or other fluid flow (the fluid flow to be treated generally referred to herein as “exhaust”) can be treated (e.g., one or more pollutants removed or abated) as the exhaust is flowed from the inlet 14 to the outlet 16 through the assembly 10. To this end, the assembly 10 further comprises a heater assembly 18 and an aftertreatment component 20 located between the inlet 14 and outlet 16. For example, the aftertreatment component 20 can be a catalyst-loaded substrate, a particulate filter, or a catalyst-loaded particulate filter. For example, catalyst substrates and particulate filters can comprise a porous ceramic honeycomb body having an array of walls that form a plurality of fluid flow paths or channels extending axially (in the direction of exhaust flow and/or perpendicular to the end faces of the body) through the body.

[0061] As described in more detail herein, the heater assembly 18 can be a resistance heater that provides supplemental heat in order to facilitate functionality of the aftertreatment component 20, e.g., by quickly initiating light-off of catalytic material disposed in or on the walls of the heater assembly 18 and/or the aftertreatment component 20. For example, the heater assembly 18 can comprise, or otherwise be connected to, electrodes 22. The electrodes 22 can be arranged extending through the housing 12 in order to connect the heater assembly 18 to a power source, such as a vehicle battery. As shown in FIG. 1, the electrodes 22 can extend radially through the housing 12. However, the electrodes 22 can alternatively extend axially through the housing 12 and/or one could extend radially while the other extends axially. In this way, the heater assembly 18 can be arranged to generate heat via Joule heating when the heater assembly 18 is connected to a power source and a corresponding voltage is applied to flow current through the walls of the heater assembly 18. The electrodes 22 are shown in FIG. 1 as being arranged on opposite sides of the heater assembly 18 (e.g., spaced 180° apart with respect to the exterior of the heater assembly 18), but can be arranged at other locations or angles.

[0062] In embodiments disclosed herein, such as shown in FIG. 1, the heater assembly 18 is positioned upstream (relatively to the direction of exhaust flow) of the aftertreatment component 20 in order to increase the temperature of the exhaust flow and/or provide direct heating to the aftertreatment component 20. This in turn increases the temperature of the aftertreatment component 20, such as the temperature of the catalytic material carried by the aftertreatment component 20, as the exhaust flows through the aftertreatment component 20. In some embodiments, the heater assembly 18 and the aftertreatment component 20 can be effectively combined into a single device by directly loading the body of the heater assembly 18 with a catalyst. Such arrangements useful for heating a catalyst material may be referred to as an electrically heated catalyst, or EHC.

[0063] A vehicle exhaust system can be created by connecting additional lengths of piping (not shown) to the assembly 10 at the inlet 14 (e.g., extending between the inlet 14 and the engine exhaust manifold) and outlet 16 (e.g., extending from the outlet 16 to the tail pipe). Depending on the design or configuration of the exhaust system, which vary vehicle to vehicle, the various components and/or lengths of piping can have different diameters at different positions along the flow path through the exhaust system.

[0064] The heater assembly 18 and the aftertreatment component 20 can be held in place, supported, and/or contained within the housing 12 in any suitable manner. For example, the body of the heater assembly 18 can be held in place and supported via one or more retainers 24, e.g., retaining rings. The aftertreatment component 20 can be supported by similar retainers and/or supported by a mat 26, such as an inorganic fiber mat, which assists in protecting the aftertreatment component, such as from vibrations or thermal expansion forces exerted on the aftertreatment component 20 during operation.

[0065] Referring now to FIGS. 2-3, one embodiment for the heater assembly 18 is illustrated. Consistent with the disclosure herein, the embodiments illustrated and/or described herein can be used as, or incorporated in, the heater assembly 18 in the assembly 10, and combinations of the features of the embodiments illustrated or described herein can be used together for the heater assembly 18 in the assembly 10.

[0066] As described further herein, the heater assembly 18 comprises a heater body 30 comprised of electrically conductive material that extends in a serpentine current-carrying path (or simply, “serpentine path”) between a pair of electrodes (e.g., the electrodes 22, not shown in FIGS. 2-3). A portion of the serpentine path for the heater body 30 is identified by a dashed lined and the reference numeral 32 in FIG. 2. As described further herein, the serpentine path 32 for the body 30 results from a plurality of slots 34 extending into the body 30 from an outer periphery 36 of the body 30.

[0067] Current flow along the serpentine path 32 of the heater body 30 (such as a honeycomb body) can be achieved via electrodes, such as the electrodes 22 (see FIG. 1, not shown in FIG. 2) at opposite ends of the serpentine path 32. The electrodes 22, or portions thereof, can be integrally formed with the heater body 30, or separately attached, such as via mechanical fastening or welding, for example at corresponding electrode attachment sites 38. In this way, an electrical connection can be established along the serpentine path 32 through the body 30 via the electrodes secured at the opposite ends. For example, the properties of the honeycomb body 30, such as the dimensions of the honeycomb body 30, the length of the serpentine path 32, the area of the electrically conductive material of the heater body 30 available for current flow per unit length along the serpentine path 32, and/or resistivity of the material of the honeycomb body 30, can be set with respect to a targeted or selected voltage intended to be applied across the electrodes 22 in order to generate heat via resistance heating as electrical current passes through the material of the heater body 30.

[0068] In embodiments, the heater body 30 is arranged with respect to a selected voltage (e.g., a voltage available for use by the heater assembly 18 from a vehicle’s battery) to reach a temperature suitable for catalyst light off, such as between about 700°C and 1000°C, although other temperatures can be targeted based on the application of the heater assembly 18 and/or the thermomechanical properties of the material selected for the heater body 30. In embodiments, the material of the heater body 30 comprises a metal, metal alloy, or metal composite. For example, various metal alloys are particularly advantageous for use in resistance heating elements due to their thermomechanical, environmental resistance, and electrical properties. In embodiments, the metal comprises an alloy comprising one or more of nickel, chromium, iron, and/or aluminum, such as a nickel-chromium alloy or an iron- chromium-aluminum alloy, although other materials suitable for use in or as resistance heaters can be used. However, since these materials comprise metals, these materials generally have a fairly high conductivity. Advantageously, the back-and-forth traversal of the serpentine designs described herein enables the current carrying path length for the heater body to be many times longer than the diameter of the heater body, such that the overall resistance of the heater body 30 between the electrodes can be made high enough to reach sufficient temperatures, while maintaining a compact size to the heater body. In some examples, the materials of the heater body 30 comprise Inconel®, a nickel-chromium -based superalloy.

[0069] In the illustrated embodiments, the body 30 comprises an array or matrix of intersecting walls 40 (e.g., see FIG. 3), which form a plurality of channels (fluid flow paths) extending in an axial direction through the body 30, and thus is of the type that may be referred to as a honeycomb body. The channels provide flow paths that enable a fluid to flow through the body 30 (e.g., a flow of exhaust fluid), while the intersecting walls 40 act as resistive elements to generate heat when a voltage is applied to the body 30 and also provide surface area for heat exchange with the fluid flow. Each of the sections of the walls 40 that are enclosed together to define a flow channel may be referred to herein as a cell 42. Accordingly, as seen in FIG. 2 and 3, the array of intersecting walls 40 define a corresponding array of square-shaped cells 42, which together create the honeycomb design for the body 30.

[0070] As mentioned above, the body 30 comprises the slots 34, which create disconnections, e.g., gaps, in the heater body 30 to break electrical conductivity at certain locations in the body 30. For example, the slots 34 severe, break, disconnect, or otherwise electrically isolate portions of the body 30 from each other, thereby forcing electrical current to flow in the designated serpentine path 32 around these disconnected portions. For example, the slots 34 can be air gaps, or filled with an electrically insulating material. Each of the slots 34 comprises an open end 44 where the slot 34 intersects with the outer periphery 36 of the body 30, and a terminal end 46 at which the slot 34 terminates within the heater body 30. In the example of FIG. 3, the terminal end 46 is rounded, though in other examples, the terminal end 46 may be square.

[0071] As shown in FIG. 2, the slots 34 extend across the body 30 altematingly from opposite sides of the body 30, such that the material of the body 30 (e.g., intersecting walls 40) is connected together in a serpentine pattern 32 that doubles back on itself across the body 30 multiple times.

[0072] As further shown in FIG. 3, the slots 34 have a width W and a length L extending from the open end 44 to the terminal end 46 (only a portion of the length L is shown). If necessary, the length L of each slot 34 can be determined as the longest dimension of each slot 34 between the terminal end 46 and the open end 44, such as in the illustrated embodiment, for example, since the slot 34 intersects the outer periphery 36 over a small range of distances because the outer periphery 36 is curved. The lengths L and/or widths W can vary for different slots 34. As a result, electrical current carried through the material of the body 30 between the electrodes 22 is forced along the serpentine path 32. The shape or design of the serpentine path is not limited to that shown in the figures, as the number of the slots 34, as well as the lengths, angles, widths, or other dimensions can be set in order to define the shape and/or dimensions of the serpentine path.

[0073] In embodiments in which the heater body 30 is formed as a honeycomb design, such as in the illustrated embodiment in which the heater body 30 comprises the intersecting array of walls 40, the width W can be equal to the combined width of one or more whole cells 42 formed by the intersecting walls 40. For example, the width W is equal to the width of one whole cell 42 in FIG. 3.

[0074] Accordingly, the electrical disconnections caused by the slots 34 enables the current path length between the electrodes 22 to be increased, as the electrical current is forced to traverse back and forth across the body 30 multiple times instead of flowing in a straight line directly between the electrodes 22. Since the overall resistance of the heater body 30 is dependent (in part) on the overall current-carrying path length between the electrodes 22, the electrical resistance of the heater assembly 18 can be set, at least in part, by selecting the dimensions, locations, and number of slots 34 (thereby setting the parameters of the serpentine current-carrying path). For example, as described herein, the serpentine design enables the heater body 30 to be formed as a relatively small, thin disc of a desirable metal alloy or other material while also generally temperatures in the hundreds of degrees Celsius.

[0075] In embodiments, with respect to the axial direction, the heater body 30 is at most 1 inch thick, at most 0.75 inches thick, at most 0.5 inches thick, such as from 0. 1 inches to 1 inch, from 0. 1 inches to 0.75 inches, from 0. 1 inches to 0.5 inches, or from 0.25 inches to 0.5 inches. In embodiments, the diameter (or widest dimension perpendicular to the axial direction) is at most 10 inches, at most 9 inches, at most 8 inches, at most 7 inches, at most 6 inches, at most 5 inches, at most 4 inches, such as from 4 inches to 10 inches, although the size of the heater body can be arranged based on the particular application, such as to correspond generally to the cross-sectional size of the catalyst substrate or fdter with which the heater is used.

[0076] Since the slots 34 provide electrical isolation, the terminal ends 46 of the slots 34 correspond to the locations where the serpentine path 32 bends around the slots 34, and thus represent the locations at which the current flow changes direction. It has been found that these bends in the serpentine path 32 can result in more heat generation, and therefore high- temperature “hot spots” to be formed due to concentration of current flow at the terminal ends 46. That is, current flow will tend to concentrate along the shortest path through the bends, which corresponds to the material of the heater body 30 that directly abuts and/or bounds against the terminal ends 46 of the slots 34. Such hot spots may cause these areas of the heater body 30 to be particularly prone to premature failure, breakage, cracking, bending, warping, or other degradation in mechanical or thermomechanical properties or performance, especially as the heater assembly 18 undergoes increasing numbers of heating and cooling cycles during use. [0077] Furthermore, due in part to the concentration of current flow through the material of the heater body 30 directly against to the terminal ends 46, the material of the heater body 30 beyond the terminal ends 46 (in the direction that the slots 34 extend into the heater body 30) will be rapidly cooler than both the hot spots and the rest of the heater body 30. This rapid cooling results because there is increasingly less current flow in the material of the heater body 30 as the distance toward the outer periphery 36 from the terminal end 46 increases. [0078] In consideration of the above, and as shown in FIGS. 2-3, the serpentine path 32 can be defined along a plurality of core segments 48 and a plurality of end regions 50 of the heater body 30. More particularly, each of the core segments 48 is defined as the electrically conductive material of the heater body 30 that extends between and along each pair of adjacent ones of the slots 34, while the end regions 50 comprise the electrically conductive material of the heater body 30 in the areas proximate to the terminal ends 46 where the serpentine path 32 bends.

[0079] Examples of the general areas corresponding to the core segments 48 and the end regions 50 are identified in the figures. However, since the core segments 48 and the end regions 50 are each formed from the electrically conductive material of the heater body 30 (e.g., the core segments 48 and the end regions 50 can be integrally formed from electrically conductive material as part of the same structure, such as both being formed from, or as part of, the array of intersecting walls 40 shown in the figures), there may not be a physically clear delineation or demarcation between these two areas. Instead, the core segments 48 and the end regions 50 can overlap to some degree and/or there can be a transition between them.

[0080] FIG. 4 demonstrates the formation of these hot spots and cooler spots proximate to the terminal ends 46 of the slots 34. FIG. 4 illustrates a portion of a heater body 30 having two slots 34 forming a serpentine path 32 (not illustrated for clarity). The example heater body 30 comprises an array of intersecting walls 40 divided into two groups, horizontal walls 40H and vertical walls 40V. The intersections of the horizontal walls 40H and the vertical walls 40V form a plurality of cells 42. The horizontal walls 40H are defined as extending parallel to a primary direction PD, while the vertical walls extend perpendicular to the primary direction PD. The primary direction is also parallel to each slot 34. Each of the walls 40H,40V comprise conductive material, such as a metal, metal alloy (or super alloy), or metal composite. Accordingly, current I flows from one end of the serpentine path to the other via the walls 40. Current I flows along the path of least resistance. Thus, as current I flows along the horizontal walls 40H towards the terminal end 46 of each slot 34, a high percentage of the current I “short circuits” by flowing down the vertical wall 40V adjacent to the terminal end 46 rather than flowing throughout the entire heater body 30 in a more evenly distributed manner. This short circuit effect is demonstrated by the downward-angled arrows in FIG. 4. This high percentage of current I results in high joule heating around the terminal end 46, and consequently the formation of a hot spot HS. These hot spots HS negatively impact power consumption and temperature uniformity within the heater body 30. These hot spots HS limit potential applications of the heater body 30 since the usable material temperature window is mostly consumed by the high temperature at the hot spots HS. Similarly, the short circuit effect also significantly reduces the current I reaching the outer comers of the serpentine path 32, resulting in the formation of cold spots CS. The heater body 30 may be unable to sufficiently heat exhaust gas travelling through cells 42 within the cold spots CS, resulting in uneven heating and reduced effectiveness of the heater body 30 overall.

[0081] FIGS. 5-7 illustrate a novel, non-uniform cell design to reduce the impact of the hot spots HS shown in FIG. 4. In particular, like FIG. 4, FIG. 5 illustrates a portion of a heater body 30 having two slots 34a, b forming a serpentine path 32 (not illustrated for clarity). The illustrated portion of the heater body 30 includes three core segments 48a-c and two end segments 50a, b. A first core segment 48a is coupled to a first end segment 50a. A second core segment 48b is coupled to the first end segment 50a and a second end segment 50b. A third core segment 48c is coupled to the second end segment 50b. Notably, each core segment 48a- c includes two types of cells 42, square cells 42q and skewed cells 42k. While each core segment 48a-c of FIGS. 5-7 comprises two rows of square cells 42q and skewed cells 42k, any number of rows may be implemented depending on the desired application. As can be seen in FIG. 5, the square cells 42q are formed by intersecting horizontal walls 40H and vertical walls 40V, wherein the horizontal walls 40H extend parallel to the primary direction PD, which the vertical walls 40V extend perpendicularly to the primary direction PD. Accordingly, the square cells 42q formed by these intersections are substantially square in shape, having four sides of approximately equal length meeting at ninety-degree angles. By contrast, the skewed cells 42k are formed by the intersection of horizontal walls 40H extending parallel to the primary direction PD with skewed vertical walls 40V oriented at an intersection angle 58 (see FIG. 6) greater than or less than (but not equal to) ninety degrees. Accordingly, these intersections form skewed cells 42k having four sides of varying length meeting to form non-ninety-degree angles. The skewed cells 42k may resemble rhombuses, parallelograms, trapezoids, or other non-rectangular shapes. Similarly, the end segments 50a, b comprise cells 42 in a substantially trapezoidal shape. Further to the non-limiting example of FIG. 5, the skewed cells 42k of each core segment 48a-c become increasingly skewed along primary direction PD and with proximity to the terminal ends 46a, b of the slots 34a, b. As will be demonstrated with respect to FIG. 6, the varying skewedness of the cells 42k may be described in terms of intersection angles 58 formed by the intersecting walls 40, cross-sectional area of the cells 42, and/or lengths of electrically conductive paths 60.

[0082] Skewing the cells 42 of the heater body 30 near the terminal ends 46a, b of the slots 34a, b reduces the concentration of electrical current, as the path of least resistance from each horizontal wall 40h around each slot 34a, b is no longer necessarily along the vertical wall 40v immediately adjacent to the terminal end 46a, b. These dispersed electrical current paths I are illustrated by downward-angled arrows where the core segments 48a-c meet the end segments 50a,b. Aside from reducing the impact of hot spots, the dispersed electrical current I also reduces the impact of cold spots by directing the electrical current I to the outer comers of the serpentine path 32. Reducing the impact of hot and cold spots enables the electrical heater 18 to effectively utilize the temperature window of the material(s) comprising the heater body 30, and improves gas temperature uniformity as exhaust gas exits the cells 42 of the heater body 30. This skewed design may be readily manufactured by additive manufacturing or extrusion techniques without further innovation. Indeed, skewing the cells 42 results in less material used than previous designs. Further, the larger cross-sectional area of the skewed cells 42k compared to square cells 42q results in lower fluid flow impedance through the channels of the heater body 30 for more effective heat exchange between the heater body 30 and the exhaust gas. Additionally, the hot spot reduction may reduce physical stresses at terminal ends 46a, b due to excessive heating. The reduction of hot spots and cold spots is shown with further detail in FIG. 8.

[0083] FIG. 6 is a further illustration of the portion of the heater body 30 shown in FIG. 5. In FIG. 6, the second core segment 48b (see FIG. 5) is conceptually divided into three portions, a square cell portion 52 arranged between a first skewed cell portion 54 and a second skewed cell portion 56. The first skewed cell portion 54 is coupled to the first end portion 50a (see FIG. 5), and the second skewed cell portion 56 is coupled to the second end portion 50b (see FIG. 5). The square cell portion 52 comprises the square cells 42q of the second core segment 48b, while the first and second skewed cell portion 54, 56 comprise the skewed cells 42k of the second core segment 48b.

[0084] In some embodiments, a skew ratio of one of the core segments 48 may be determined as the total number of skewed cells 42k divided by the total number of square cells 42q within the core segment 48. Accordingly, in the illustrative embodiment of FIG. 6, skew ratio of the second core segment 48b may be approximately 2.00, the first skewed segment 54 and the second skewed segment 56 each appear to have the same amount of cells 42 as the square segment 52. However, in more practical embodiments, the total number of square cells 42q may significantly outnumber the skewed cells 42k in a core segment 48. In a preferred embodiment, and as will be illustrated in subsequent figures, the skew ratio may be 0.15 (or 15%), meaning that the core segment has 6.67 square cells 42q for every skewed cell 42k.

[0085] FIG. 6 further depicts three intersection angles 58a-c formed by the intersecting horizontal walls 40H and vertical walls 40V within the second core segment 48b. A first intersection angle 58a is illustrated within the square cell portion 52 of the second core segment 48b. As shown in FIG. 6, the first intersection angle 58a is approximately ninety degrees. Indeed, due to the square-shape of all of the cells 42 within the square cell portion 52, each intersection angle 58 within the square cell portion 52 is approximately ninety degrees.

[0086] A second intersection angle 58b is illustrated within the first skewed cell portion 54. As shown, the illustrated second intersection angle 58b is greater than ninety degrees, for example, 120 degrees. As can been seen in FIG. 6, the intersection angle 58b formed by the intersections of the horizontal walls 40H and vertical walls 40V within the first skewed portion 54 incrementally increases along the primary direction PD until the first skewed portion 54 meets first end segment 50a (see FIG. 5). In other examples, all (or a subset of) the intersection angles 58b within the first skewed cell portion 54 may be substantially equal.

[0087] A third intersection angle 58c is illustrated within the second skewed cell portion 56. As shown, the illustrated third intersection angle 58c is greater than ninety degrees, for example, 120 degrees. As can been seen in FIG. 6, the intersection angle 58b formed by the intersections of the horizontal walls 40H and vertical walls 40V within the second skewed portion 56 incrementally decreases along the primary direction PD until the second skewed portion 56 meets the square cell portion 52. In other examples, all (or a subset of) the intersection angles 58b within the first skewed cell portion 54 may be substantially equal.

[0088] As further illustrated in FIG. 6, the third core segment 48c (see FIG. 5) is conceptually divided into two portions, a square cell portion 62 arranged adjacent to a skewed cell portion 62. The skewed cell portion 62 is coupled to the second end portion 50b. The square cell portion 52 comprises the square cells 42q of the third core segment 48c, while the skewed cell portion comprised the skewed cells 42k of the third core segment 48b. Further, a fourth intersection angle 58d is illustrated within the third core segment 48c. The fourth intersection angle 58d is less than ninety degrees, such as sixty degrees. As can been seen in FIG. 6, the intersection angles 58d formed by the intersections of the horizontal walls 40H and vertical walls 40V within the skewed cell portion 62 incrementally increase along the primary direction PD until the skewed portion 62 meets the square cell portion 62.

[0089] Along with the intersection angles 58a-d varying along the primary direction, the cross-sectional areas of the cells 42 depicted in FIG. 6 may also vary in a similar fashion. For example, the square cells 42q within the square cell portions 52, 62 of the second and third core segments 48b, c all have approximately equal cross-sectional area. However, the cross- sectional areas of the skewed cells 42k within the first skewed portion 54 of the second core segment 48a incrementally increase along the primary direction PD. Conversely, the cross- sectional areas of the skewed cells 42k within the second skewed portion 56 of the second core segment 48a and the skewed portion 62 of the third core segment 48c incrementally decrease along the primary direction PD.

[0090] FIG. 6 further illustrates several electrical conduction paths 60a-c from a first horizontal wall 40H1 to a terminal end 46a (see FIG. 5) of the first slot 34 (see FIG. 5). These electrical conduction paths 60a-c demonstrate that the length of each path 60a-c incrementally varies along the primary direction PD due to the skewed-shape of the corresponding cells 42. As can be seen in FIG. 6, a first electrical conduction path 60a is shorter than a second electrical conduction path 60b, and the second electrical conduction path 60 is shorter than a third electrical conduction path 60c, meaning that the length of the electrical conduction paths 60a- c incrementally increase along the primary direction PD.

[0091] FIG. 7 illustrates a variation of the portion of the heater body 30 of FIGS. 5 and 6 where the terminal ends 46 of the slots 34 are substantially rounded. Testing has demonstrated that rounding the terminal ends 46 of the slots further reduces the impact of hot spots HS and cold spots CS shown in FIG. 4.

[0092] In some embodiments of the variation illustrated in FIG. 7, the rounded terminal ends 46 of the slots 34 form perfect (or near-perfect) semi-circular shapes such that the outermost skewed vertical walls 40V1-40V4 perpendicularly intercept the corresponding rounded terminal end 46. This perpendicular arrangement may prevent aspects of the heater body 30 from cracking during thermal cycling.

[0093] In some embodiments of the variation illustrated in FIG. 7, the heater body 30 may be further defined by a set of horizontal walls 40H1-40H9 and a set of vertical walls 40V5- 40V8 arranged within the end segments 50a, b (see FIG. 6). In some examples, a first plurality of intersections formed by horizontal wall 40H2 and vertical wall 40V5, horizontal wall 40H5 and vertical wall 40V5, horizontal wall 40H5 and vertical wall 40V7, and horizontal wall 40H8 and vertical wall 40V7 may be curved, rather than substantially square. In some examples, each of the first plurality of intersections may be filleted rather than curved.

[0094] In further examples, a second plurality of intersections formed by horizontal wall 40H1 and vertical wall 40V6, horizontal wall 40H6 and vertical wall 40V6, horizontal wall 40H4 and vertical wall 40V8, and horizontal wall 40H9 and vertical wall 40V8 may be filleted, rather than substantially square. In these filleted examples, excess material on the inner edge of each of the second plurality of intersections forms a radius. This radius perpendicularly intersects one of the outermost skewed vertical walls 40V1-40V4. Filleting, rather than curving, the second plurality of intersections also maintains the overall shape of the heater body 30. Generally, replacing the square intersections with curved or filleted intersections may prevent cracking during thermal cycling. Further, the filleted second plurality of intersections allows for the outermost horizontal walls 40Hl,40H9 to connect skewed cells 42k (see FIG. 5) on one side of the walls 40Hl,40H9 with square cells 42q (see FIG. 5) on the other side of the walls 40Hl,40H9.

[0095] In some embodiments of the non-uniform cell designs of FIGS. 5-7, each skewed cell 42k may be defined by a top horizontal dimension and a bottom horizontal dimension. In these embodiments, the top horizontal dimension of every skewed cell 42k may be of equal length, and the bottom horizontal dimension of every skewed cell 42k may also be of equal length. However, due to the skewed nature of the skewed cells 42k, the top horizontal dimension and the bottom horizontal dimension will be of different lengths. This configuration may lead to improved balance of current flow throughout the heater body 30.

[0096] FIGS. 8A and 8B show modeling results of power density (watts per cubic meter) in two example heater bodies 30a,b. In these examples, power density correlates to the heat generated by the heater body 30a,b, and therefore the heater bodies 30a,b ability to warm exhaust gas flowing through channels formed by an array of intersecting walls. The heater body 30a of FIG. 8A corresponds to the design of FIG. 4, where all cells are substantially square, while the heater body 30b of FIG. 8B corresponds to the design of FIGS. 5 and 6, where at least a portion of the cells proximate to the terminal ends 46 of the slots 34 are substantially skewed. [0097] FIGS. 8 A and 8B demonstrate that the cold zones within the square-cell heater body 30a consume a greater amount of power in the skewed-cell heater body 30b, resulting in warmer zones instead of cold zones. As the total power consumed by both heater bodies 30a,b is equal, the increased power to the warmer zones in heater body 30b also necessarily reduces the power in the original hotter zones. Accordingly, the skewed design of the heater body 30b of FIG. 8B results in more even power density distribution, reducing the power consumption at the hottest portions of the heater body 30b.

[0098] FIGS. 9A and 9B show modeling results of power density of the peak power consumption portions of the two example heater bodies 30a, b of FIGS. 8A and 8B. Both FIGS. 9A and 9B focus on a portion of a vertical wall 40Va, 40Vb adjacent to slot 34. As shown in FIG. 9A, the peak power density within the vertical wall 40Va of the square-cell heater body 30a is mostly constant throughout the circled portion. However, as shown in FIG. 9B, the peak power density within the vertical wall 40Vb of the skewed cell heater body 30b is not as constant, resulting in less total power consumed by vertical wall 40Vb than vertical wall 40a.

[0099] FIGS. 10A-15B illustrate a design optimization rule of the skewed cell design. As demonstrated in the previous figures, a heater body 30 may comprise a number of core segments 48 (see FIG. 5) connected by end segments 50 (see FIG. 5) to form a conductive serpentine path 32 (see FIG. 2) around a plurality of slots 34 (see FIG. 5) cut into a heater body 30. Each of these core segments 48 comprises a plurality of square cells 42q (see FIG. 5) and a plurality of skewed cells 42k (see FIG. 5). The skewed cells 42k are arranged around terminal ends 46 of the slots 34 to reduce the impact of hot spots and cold spots.

[00100] As previously discussed, a skew ratio may be determined as the total number of skewed cells 42k divided by the total number of square cells 42q within a core segment 48. Modelling has shown that optimized performance of a heater body 30 is achieved by designing each core segment 48 as having an equal skew ratio. As the length of the core segments 48 may fluctuate throughout the heater body 30, the number of square cells 42q and skewed cells 42k should be adjusted to maintain an equal skew ratio in each core segment 48.

[00101] FIG. 10A illustrates a front view of a model of a heater body 30 having a plurality of core segments 48. As can be seen, each core segment 48 comprises approximately the same number of skewed cells 42k. However, as the core segments 48 vary in length, the core segments 48 comprise different numbers of square cells 42q. Accordingly, the core segments 48 of different lengths will necessarily have different skew ratios. [00102] FIG. 10B shows a temperature profile modeled based on the heater body 30 of FIG. 10A. This temperature profile demonstrates the impact of failing to implement the equal skew ratio design rule. As can be seen in FIG. 10B, the temperatures in the shorter core segments 48 are significantly hotter than the longer core segments. Even those the skewed cells 42k reduce the temperature around the terminal ends 46 of the slots, the middle portions of the shorter core segments 48 reach temperatures over 1000 degrees Celsius, beyond the acceptable limit of the materials comprising the heater body 30. Further, the uneven nature of the temperature profile reduces overall efficiency of the heater body 30.

[00103] FIG. 11A illustrates a heater body 30 implementing the equal skew ratio design rule. As the core segments 48 vary in length, the number of square cells 42q and skewed cells 42k adjust to maintain an equal skew ratio throughout the heater body 30. The impact of the equal skew ratio design rule is shown in FIG. 1 IB. FIG. 1 IB shows a temperature profile modeled based on the heater body 30 of FIG. 11 A. The modeled temperature profile of FIG. 11B is more evenly distributed throughout different core segments than the profile of FIG. 10B, resulting in more efficient heating of exhaust gas. Further, the peak temperature of the profile of FIG. 1 IB is significantly lower than the peak temperature modeled in FIG. 10B. Accordingly, implementing the equal skew ratio design rule results in significant improvements in terms of temperature distribution and peak temperature.

[00104] FIG. 12 shows a model of a baseline heater body 30BAS for comparison to the heater body 30 of FIG. 11A implementing the equal skew ration design rule. The baseline heater body 30BAS is exclusively comprised of square cells 42q, similar to the portion of the heater body 30 illustrated in FIG. 4. The baseline heater body 30BAS further implements a series of V- shaped features 64 for hot spot mitigation purposes. The V-shaped features 64 are typically comprised of the same electrically conductive material(s) as the rest of the baseline heater body 30BAS, such as a metal, metal alloy, or metal composite.

[00105] FIGS. 13 and 14 compare the modeled temperature performance of the baseline heater body 30BAS to the heater body 30 of FIG. 11A implementing the equal skew ratio design rule. In these plots, “squared” refers to the baseline heater body 30BAS, while “skewed” refers to the heater body 30 implementing the equal skew ratio design rule.

[00106] FIG. 13 compares the maximum temperature over time of the squared design to the skewed design. FIG. 13 demonstrates that the skewed design not only heats up faster than the squared design, but the skewed design also maintains a lower peak temperature as a thermal equilibrium is approached. FIG. 13 shows the squared design having a having a peak temperature of 967 degrees Celsius at 25 seconds, while the skewed design is cooler by 45 degrees Celsius (922 degrees Celsius). The skewed design heats up quicker than the squared design due to the skewed design having a slightly lower thermal mass than the square design. The lower thermal mass may also provide the additional benefit of reduced material costs. Further, reducing the peak temperature of the squared design improves the reliability and extends the operating window of the heater body 30 implementing the skewed design.

[00107] FIG. 14 compares the gas temperature uniformity factor over time. The gas temperatures are measured 25 millimeters downstream from the squared and skewed heater bodies. FIG. 14 illustrates that the skewed design provides improved uniformity relative to the squared design.

[00108] FIGS. 15A illustrates the gas temperature distribution 25 millimeters downstream from the squared design. Similarly, FIG. 15B illustrates the gas temperature distribution 25 millimeters downstream from skewed design. As shown in FIGS. 15A and 15B, the skewed design produces a more even temperature distribution than the squared design. Further, the skewed design produces a higher mass-weighted average temperature (526 degrees Celsius) 25 millimeters downstream than the squared design (514 degrees Celsius).

[00109] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the claimed subject matter. Accordingly, the claimed subject matter is not to be restricted except in light of the attached claims and their equivalents.

Claims

Claims What is claimed is:

1 . An electrical heater body, comprising: an outer periphery; a plurality of slots, each slot extending from the outer periphery to a terminal end within the electrical heater body; a plurality of core segments comprising an electrically conductive material, wherein each core segment is defined between a different pair of adjacent slots, and wherein the electrically conductive material is shaped as an array of intersecting walls defining a honeycomb pattern of cells; and a plurality of end regions comprising the electrically conductive material, wherein each end region is between a respective one of the terminal ends of the slots and the outer periphery, and wherein each pair of adjacent core segments is connected by a corresponding one of the plurality of end regions; wherein the plurality of slots disconnects each pair of adjacent core segments from each other to create an electrically conductive serpentine path; and wherein a first group of the array of intersecting walls extend in a primary direction parallel to the plurality of slots, a second group of the array of intersecting walls intersect the first group of walls at a plurality of intersection angles, and at least a portion of the plurality of intersection angles in each of the plurality of core segments varies along the primary direction.

2. The electrical heater body of claim 1, wherein each core segment of the plurality of core segments comprises: a square cell portion, wherein each of the plurality of intersection angles within the square cell portion is substantially ninety degrees; a first skewed cell portion coupling the square cell portion to a first end region of the plurality of end regions, wherein each of the plurality of intersection angles within the first skewed cell portion is greater than ninety degrees; and a second skewed cell portion coupling the square cell portion to a second end region of the plurality of end regions, wherein each of the plurality of intersection angles within the second skewed cell portion is greater than ninety degrees.

3. The electrical heater body of claim 2, wherein, within the first skewed cell portion, the plurality of intersection angles incrementally increases in size along the primary direction from the square cell portion towards the first end regions.

4. The electrical heater body of claim 2, wherein, within the second skewed cell portion, the plurality of intersection angles incrementally decreases in size along the primary direction from the second end region towards the square cell portion.

5. The electrical heater body of claim 2, wherein each of the plurality of core segments has an equal skew ratio.

6. The electrical heater body of claim 5, wherein the skew ratio of one of the plurality of core segments is defined as a ratio of a number of cells within the first skewed cell portion and the second skewed cell portion to a number of cells within the square cell portion.

7. The electrical heater body of claim 5, wherein each of the plurality of core segments has a skew ratio of approximately fifteen percent.

8. The electrical heater body of claim 1, wherein a portion of the honeycomb pattern of cells within the plurality of end regions are substantially trapezoidal.

9. The electrical heater body of claim 1, wherein the electrically conductive material comprises a metal, a metal alloy, metal composite, or combination thereof.

10. The electrical heater body of claim 1, wherein the electrically conductive material is a nickel-chromium-based superalloy.

11. The electrical heater body of claim 1, wherein the electrical heater body is formed via additive manufacturing or extrusion.

12. The electrical heater body of claim 1, wherein the terminal end of each of the plurality of slots is rounded.

13. An electrical heater assembly comprising the electrical heater body of claim 1 coupled to a pair of electrodes at opposite ends of the electrically conductive serpentine path.

14. An electrical heater body, comprising: an outer periphery; a plurality of slots, each slot extending from the outer periphery to a terminal end within the electrical heater body; a plurality of core segments comprising an electrically conductive material, wherein each core segment is defined between a different pair of adjacent slots, and wherein the electrically conductive material is shaped as an array of intersecting walls defining a honeycomb pattern of cells; a plurality of end regions comprising the electrically conductive material, wherein each end region is between a respective one of the terminal ends of the slots and the outer periphery, and wherein each pair of adjacent core segments is connected by a corresponding one of the plurality of end regions; wherein the plurality of slots disconnects each pair of adjacent core segments from each other to create an electrically conductive serpentine path; and wherein at least a portion of the honeycomb pattern of cells varies in cross-sectional area along a primary direction parallel to the plurality of slots.

15. The electrical heater body of claim 14, wherein each core segment of the plurality of core segments comprises: a square cell portion, wherein a square cross-sectional area of each cell of the honeycomb pattern of cells within the square cell portion is substantially equal; a first skewed cell portion coupling the square cell portion to a first end region of the plurality of end regions, wherein a first skewed cross-sectional area of each cell of the honeycomb pattern of cells within the first skewed cell portion is greater than the square cross- sectional area; and a second skewed cell portion coupling the square cell portion to a second end region of the plurality of end regions, wherein a second skewed cross-sectional area of each cell of the honeycomb pattern of cells within the first skewed cell portion is greater than the square cross- sectional area.

16. The electrical heater body of claim 15, wherein, within the first skewed cell portion, the cross-sectional area of each cell incrementally increases along the primary direction from the square cell portion towards the first end region.

17. The electrical heater body of claim 15, wherein, within the second skewed cell portion, the cross-sectional area of each cell incrementally decreases along the primary direction from the second end region towards the square cell portion.

18. The electrical heater body of claim 14, wherein the terminal end of each of the plurality of slots is rounded.

19. The electrical heater body of claim 14, wherein each of the plurality of core segments has an equal skew ratio.

20. An electrical heater body, comprising: an outer periphery; a plurality of slots, each slot extending from the outer periphery to a terminal end within the electrical heater body; a plurality of core segments comprising an electrically conductive material, wherein each core segment is defined between a different pair of adjacent slots, and wherein the electrically conductive material is shaped as an array of intersecting walls defining a honeycomb pattern of cells; and a plurality of end regions comprising the electrically conductive material, wherein each end region is between a respective one of the terminal ends of the slots and the outer periphery, and wherein each pair of adjacent core segments is connected by a corresponding one of the plurality of end regions; wherein the plurality of slots disconnects each pair of adjacent core segments from each other to create an electrically conductive serpentine path; and wherein a first group of the array of intersecting walls extend in the primary direction parallel to the plurality of slots, a second group of the array of intersecting walls intersect the first group of walls at a plurality of intersection angles, and each of a plurality of electrical conduction paths defined from the first group of the array of intersection walls to one of the slots incrementally varies along the primary direction.