FLUID CIRCUIT FOR UNIFORM SPRAYING AT HIGH SPEED OVER A RANGE OF OPERATING TEMPERATURES

Abstract

The invention relates to a fluidic geometry for producing uniform oscillating sprays. The geometry can be in the form of an insert, a housing, or a system in which an inlet feeds an interaction chamber. A major island is disposed at the upstream end of this chamber to create two power nozzles positioned off-center and downstream of the major island. A minor island is also disposed within the interaction chamber, but remains spaced and downstream of the major island to define an exchange channel. The exchange channel creates an inertial effect that can be controlled and adjusted to provide the desired oscillating spray pattern produced by the geometry. This arrangement exhibits consistent performance at both low and high temperatures across a range of fluid compositions and operating conditions.

Description

Title of the invention: FLUID CIRCUIT FOR UNIFORM SPRAYING AT HIGH SPEED OVER A RANGE OF OPERATING TEMPERATURES

[0001] REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from United States Provisional Patent Application Serial No. 63 / 548,044 filed on November 10, 2023, which is incorporated by reference herein. FIELD OF THE INVENTION

[0003] This invention relates to fluidic systems, components, and apparatuses capable of producing controllable oscillating spray patterns and, more particularly, to a fluidic geometry for generating precisely controlled sprays at cooler temperatures typically associated with higher viscosity fluids.

[0004] CONTEXT

[0005] United States Patent 6,186,409 (which is incorporated by reference) provides an example of a fluidic system colloquially known as having a "mushroom" configuration. In this patent, a chip or insert has a pattern of orifices formed within one of its surfaces, provided that the insert is sealed within a housing that receives a fluid, supplies the fluid to an inlet or plenum formed on the insert, and then the outlet of the insert is aligned with an orifice in the housing such that the housing dispenses a fan of spray through that orifice. Due to the geometric configuration formed on the insert, the dispensed spray may oscillate or otherwise possess specific characteristics.

[0006] Many other fluidic geometries are known, so the mushroom configuration serves only as one example. However, it is instructive in that it (like these other geometries) has the features necessary to produce oscillating sprays. Specifically, the inlet / feed leads to a passageway that optionally has a series of spaced-apart pads that help filter unwanted debris from the fluid. Downstream of these pads, the passageway is divided by an "island" that diverts the fluid into one of two opposing power nozzles. The power nozzles constrict the flow and eject lateral / angled jets into an interaction or oscillation chamber having a curved or dome-like shape (defined by the downstream face of the island and the walls perimeters of the insert / housing). Upon entering this chamber, the fluid jets from the power nozzles interact to produce turbulent and moving flow patterns. Thus, upon exiting the outlet at the downstream edge of the insert, the fluid is distributed as a fan-shaped cone in which a jet moves (i.e., oscillates) so as to create a spray (in this particular example, one known as "heavy-ended," as will be described in more detail below) that is useful in various cleaning operations.

[0007] U.S. Patents 7,472,848 and 7,267,290 describe additional improvements and embodiments of other geometries and oscillating inserts, while U.S. Patents 6,253,782; 11,305,297; and 11,712,707 illustrate an "inverted mushroom" configuration in which the interaction chamber has sloping or curved sidewalls along its downstream section while the power nozzles (and possibly their corresponding feeds or inlets) are positioned closer to the outlet and at an upstream angle compared to a conventional poppet. U.S. Patent 9,987,639 describes structures that can be implemented in an outlet / constriction to produce specific effects, while U.S. Patent Publication 2021 / 0114044 discloses features on and / or in the interaction chamber. All of these patents are also incorporated by reference.

[0008] Another example of a fluid geometry ("three-jet island") is found in U.S. Patents 7,651,036 and 10,532,367, which are incorporated by reference, and is schematically shown in [Fig. 4B] (including arrows representing fluid flow / turbulence). The common feature in both of these patents relates to the positioning of three individual islands between the inlet and the interaction chamber. Thus, compared to the mushroom configuration set forth above, an additional power nozzle PN3 is actually provided on the centerline of the circuit between and above the location of power nozzles PN1, PN2. A small island IS3 is also positioned downstream of power nozzle PN3. The inlet IN3, the plenum or flow channel FC3, the interaction chamber IC3 and the outlet OT3 are similar to other geometries stated herein.This arrangement produces a more uniform oscillating spray pattern, especially compared to the heavy-tip mushroom circuit.

[0009] A comparative diagram of how the volumetric distribution can be visualized is shown in [Fig.lA], in which the percentage of total spray volume produced over time is plotted on the y-axis and the x-axis is a comparative representation of the position within the spray fan itself (i.e., the extreme left edge is representative of the dispensed volume at that edge of the fan, the middle representing the volume detected at the centerline, etc.). The mushroom circuit distribution M displays a heavy-ended distribution (having an M-shape) so that more volume is delivered at the edges of the spray pattern. Since some applications may require equal distribution across the fan, the three-jet island distribution J retains some of the "smoothness" and M-shape of the mushroom distribution, but with a smaller difference in maximum and minimum volumes. For comparison, the distribution F of a conventional "feedback loop" circuit is also shown, its most notable feature being the comparative variability and non-uniformity (or irregular / non-smooth) distribution occurring across its midsection.Thus, it will be understood that fluid circuits producing oscillating sprays can and should be further optimized based on the volumetric output of the spray fan, and that significant differences exist between known and established fluidic geometries (e.g., mushroom vs. three-jet island, etc.).

[0010] Additionally, with the increasing importance / need for cleaning sensor and camera systems, particularly in vehicles and other facilities exposed to variable and / or extreme weather conditions, there is a growing need for fluid circuits that are capable of producing and maintaining spray characteristics over a range of temperatures (e.g., -30°C to 75°C) and fluid types (e.g., water, ethanol, methanol, isopropanol, ethylene glycol, etc.). Similarly, such systems may need to accommodate fluids with varying viscosities (e.g., from 9 Cp up to 23 Cp or higher), as well as be supplied over a range of flow rates (e.g., less than 400 ml / min at 22 psi).Figures 1B and 1C provide illustrative information and guidance on the range of conditions that are typically required / encountered, with curves M25, M50 and 125,150 representing viscosity changes as a function of temperature for mixtures of 25% and 50% methanol (balance being water) and 25% and 50% isopropanol (balance being water) respectively showing a greater range of variation compared to M75, M100 (75% and 100% methanol) and 175,1100 (75% and 100% isopropanol). [Fig.lD] provides more direct comparative information, by depicting corresponding 50 / 50 mixtures of methanol (M50) versus ethanol (E50) (the remainder being water in each case), as well as by highlighting more clearly how mixtures of water and longer-chain alcohols exhibit remarkably higher viscosity at low temperatures.As it is known in this field that fluid performance can be impacted by viscosity, it will be understood that designs . fluid geometry must also take into account expected temperature fluctuations.

[0011] In the automotive industry, antifreeze agents used in cleaning solutions will vary depending on the region and / or regulatory system. Thus, various alcohols (ethanol, isopropanol, methanol, etc.) may be mixed with water or other aqueous / miscible solutions at a variety of ratios (e.g., 50 / 50, 75 / 25, etc.). Furthermore, since operating conditions typically vary from -20°C to above 45°C or 50°C, the viscosity of fluids passing through the fluid geometry may vary by a factor of 3 or more (with higher viscosities being encountered at lower temperatures).

[0012] In view of the foregoing, a geometry, insert, and / or fluidic system that produces reliable oscillating sprays over a wide range of operating parameters (e.g., temperature, fluid viscosity, low versus high flow rates, desired spray fan size / shape / volumetric distribution, etc.) would be welcome. Specifically, a geometry that will produce uniform spray patterns while accounting for the various different fluids, flow rates, and operating temperatures commonly encountered by vehicles around the world is needed. Summary of the invention

[0013] A fluid geometry is formed on an insert and / or is part of a housing or system. One or more inlets feed an interaction chamber having a major island that is disposed at the upstream end of that chamber with a minor island spaced apart and downstream of the major island so as to define an exchange channel within the interaction chamber. Two power nozzles, positioned off the centerline axis, feed the interaction chamber and the exchange channel. The side edges of the minor island are positioned so as to be within the direct path of each power nozzle, and the minor island itself may have a crescent, C-shape, or "speed bump" shape, all aligned with the centerline axis at a position upstream of the constriction and the outlet. The exchange channel creates an inertance effect that can be controlled and adjusted to provide the desired oscillating spray pattern produced by the geometry.This arrangement exhibits consistent cold and high temperature performance over a range of fluid compositions and operating conditions.

[0014] DESCRIPTIONS OF THE DRAWINGS

[0015] The accompanying drawings are part of this specification, and any information on / in the drawings is both literally encompassed (i.e., actual indicated values) and relatively encompassed (e.g., ratios for respective dimensions of parts, generalized comparatives, etc.). Likewise, the relative positioning and relationship of components as shown in these drawings, as well as their function, shape, dimensions, and appearance, may all further inform certain aspects of the invention as if completely rewritten herein. Unless otherwise indicated, all dimensions in the drawings refer to inches, and any information printed on / in the drawings is part of this written disclosure, including selected drawings that may be drawn to scale.

[0016] [Fig.lA] [Fig.lA] is a comparative plot of the volumetric distribution of sprays produced by a variety of fluidic geometries. Figures 1B [Fig.lB] and 1C [Fig.lC] plot the viscosity relationship of selected fluids (i.e., methanol and isopropanol, respectively) over a range of temperatures and mixtures of the alcohol in question with water (i.e., pure (100%) alcohol, 75 / 25 alcohol / water, etc.), including formulas for each curve / set of conditions. [Fig.lD] [Fig.lD] is a combined comparative plot of the viscosity vs. temperature relationship for 50 / 50 ethanol / water (line E50) and 50 / 50 methanol / water (line M50).

[0017] [Fig.2A] [Fig.2B] Figures 2A and 2B are three-dimensional views of the inventive fluid geometry as it may be implemented in a variety of inserts / housings, [Fig.2A] providing filter pads and a transverse inlet / feed within an inverted poppet and [Fig.2B] implementing a variable width exchange channel in a conventional poppet.

[0018] [Fig.3A] [Fig.3B] Figures 3A and 3B are schematic representations, respectively, of the geometries of Figures 2A and 2B. [Fig.3C] [Fig.3C] is a similar schematic representation, illustrating an additional variation that may be implemented on the minor island according to certain aspects of the invention.

[0019] [Fig.4A] [Fig.4A] (prior art) is a photograph of the spray pattern produced by the three-jet island geometry schematically illustrated in [Fig.4B] [Fig.4B] (prior art).

[0020] [Fig.4C] Figures 4C (prior art) (a composite view of a conventional poppet and three-jet island geometries, both as in the prior art) and [Fig.4D] 4D (as in [Fig.7]) are comparative photographs of the spray pattern for 50 / 50 ethanol blends at 0°F and 20 psi produced by each of the fluidic geometries, highlighting the uniform volume distribution and wide spray pattern of the invention compared to that of the prior art, with the three-jet island producing a narrow spray pattern and the poppet producing an irregular and narrow spray fan under these conditions.

[0021] [Fig.5A] [Fig.5A] is a photograph of the spray pattern produced by the fluidic geometry of various disclosed aspects of the invention, in which is a comparison to [Fig.4A], again highlighting the comparatively more uniform volumetric distribution of the invention compared to the prior art.

[0022] [Fig.5B] [Fig.5C] [Fig.5D] Figures 5B (start-up), 5C (time 1) and 5D (time 2) are sequential schematic illustrations of the flow patterns expected in the mushroom-shaped aspect of the invention, the arrows in these Figures being representative of fluid flows / turbulence expected at a given time.

[0023] [Fig.5E] [Fig.5F] [Fig.5G] Figures 5E (start-up), 5F (time 1) and 5D (time 2) are sequential schematic illustrations of the flow patterns expected in the inverted mushroom appearance of the invention, the arrows in these Figures again being representative of fluid flows / turbulence expected at a given time.

[0024] [Fig.6] [Fig.6] is a schematic top view of the fluid geometry of Figures 3A and 5E, with inset 6A highlighting aspects of the comparative orientation of the power nozzle relative to one of the terminal vertices on the minor island.

[0025] [Fig.7] [Fig.7] is a schematic top view of an alternative fluid geometry, also based on the two-jet island concept, but in which the tip of the minor island is positioned flush with the projection defining the power nozzle. DETAILED DESCRIPTION

[0026] The operation of the invention may be better understood with reference to the detailed description, drawings, claims, and abstract—all of which are part of this written disclosure. While specific aspects and embodiments are contemplated, it will be understood that those skilled in the art will be able to adapt and / or substitute certain teachings without departing from the underlying invention. Accordingly, this disclosure should not be read as unduly limiting the invention(s).

[0027] As used herein, the words "example" and "exemplary" mean an instance or illustration. The words "example" or "exemplary" do not indicate a key or preferred aspect or embodiment. The word "or" is intended to be inclusive rather than exclusive, unless the context suggests otherwise. For example, the phrase "A employs B or C" includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). On the other hand, the The articles "a" and "an" are generally intended to mean "one or more," unless the context suggests otherwise.

[0028] To the extent that the invention encompasses fluid circuits, it will be understood that such inserts are typically formed in or on flat cuboid-shaped "inserts" having a length and width that are significantly greater than its thickness. Thus, the fluid geometry may be etched, molded, or formed within the thickness, such that the expected flow will traverse the spatial plane defined by the length and width. Typically, the inlet(s) will be positioned in, at, or near one edge, while the outlet will be formed in the opposite edge.

[0029] These inserts may be positioned within a housing that includes passages for delivering fluid to the inlet(s) on the insert and a nozzle aligned with the outlet of the insert. In one aspect, the fluid geometry (i.e., interaction chamber, power nozzles, throttle / outlet, etc.) formed in or on the insert is aligned in the same spatial plane, which is coincident with at least one of the major flat surfaces of the insert. The fluid geometry may include boundary walls formed in or on the insert, or the geometry may be based on interior surfaces of the housing that abut the insert to define fluid flow paths therein.

[0030] In the drawings, and in particular at least in Figures 3A-3C, 4B and 5A-5G, the fluid geometry is drawn such that the inlet is at the top of each image, while the outlet is at the bottom. The flow and positioning of elements may, therefore, be described with respect to these elements as either "upstream" or "downstream". Separately, the positioning of attributes above or at the top of the insert will be understood to tend toward the upper half in which the inlet is provided, while below and at the bottom refer to those attributes closer to the outlet. The vertical sides in these images are the edges, with transverse and lateral directions generally passing from edge to edge, while axial or vertical directions refer to the flow from the inlet to the outlet.The images themselves are drawn in the common spatial plane and, unless specifically stated, planar surfaces are flat and do not have steps, ramps, or changes in elevation (relative to fluid flow on either side of that plane).

[0031] Generally, the inventive fluid geometry is characterized by a pair of opposed power nozzles aligned in a common plane. These power nozzles are fed by one or more inlets in the form of a plenum in the upstream portion of the insert. Alternatively, these inlets may be an opening or a series of orifices passing transversely through the body (i.e., orthogonal to the common plane) of the insert.

[0032] Notably, the power nozzles are not aligned with the axial centerline AA of the insert (i.e., the line passing through the middle of the housing and, usually, through the middle of the outlet and the constriction), largely because a first large or major island is positioned upstream of these power nozzles, with its transverse edges defining one side of each power nozzle, and the peripheral wall defining the entire circuit / geometry (either on the insert itself or as part of the cavity in the housing receiving the insert) defines the opposite side of this power nozzle.

[0033] A second, smaller or minor island is spaced downstream of the major island, such that the minor island is disposed within the interaction chamber. This smaller island extends transversely from edge to edge of the insert and across the common plane and is positioned symmetrically about the centerline axis. In some aspects, this smaller island has an upstream face whose shape partially or completely conforms to the downstream face of the major island and in some cases remains equidistantly spaced therefrom. The shape of the minor island may include: a) a crescent-like shape in which the edges are thinner from the upstream to downstream faces compared to along the centerline axis (e.g., as in [Fig. 3A]), b) a flat / horizontal downstream face and a curved or semi-circular upstream face (which gives a "speed bump" appearance) (e.g., as in [Fig.3B]), or c) a C-shape having thickened "serif" style portions at the edges, so as to protrude into the interaction chamber and provide a mushroom cap appearance (e.g., as in [Fig.3C]).

[0034] The terminal / outermost edges of the minor island are defined by an edge or apex 33A positioned within the initial flow path created by this power nozzle as fluid exits the nozzle and flows toward the interaction chamber (note: although this is nominally downstream, some aspects such as those shown in Figures 5E-5G may have the power nozzle directed upward at a deflecting angle toward the inlet). Generally speaking, the positioning of the edges 33A is within a pair of imaginary straight lines extending from the straight sidewalls that define the power nozzle 34, which provides lateral boundaries (i.e., the "mouth" of the power nozzle) within which the apex 33A will be positioned. More specifically and with reference to [Fig.6], if a straight line 34A is drawn across the opening at the mouth of the power nozzle 34, an offset line 34B extends orthogonally from the line 3A so as to intersect the vertex 33A, and the length of the orthogonal line 34B will be about the same as, less than twice as much as, or less than the length of the straight line 34A.

[0035] Positioning each edge of the minor island within immediate range of the mouth of each power nozzle, as described in the preceding paragraph, will split the flow ejected by each power nozzle such that at least a portion of the flow from each will be directed into the interaction chamber. In some aspects, flow from one power nozzle is split between entering the interaction chamber and the exchange channel (as defined below) while flow from the opposite power nozzle is directed into the interaction chamber until the flow patterns cause a reversal that is considered to represent the insert's ability to produce an oscillating flow pattern (e.g.,, compare Figures 5C versus 5D and 5E versus 5F), although it will be understood that the inventors do not necessarily intend to limit themselves based on any theory of operation. Furthermore, the numerous examples of oscillating fluid circuits (including those detailed in the Background of the Invention above) clearly establish that fluid mechanics can be a complicated and unpredictable endeavor in which slight changes to geometry can result in significant and useful improvements.

[0036] Providing a minor island axially below and along a downstream face of the major island creates and defines an exchange channel. Openings at opposite ends of the exchange channel are positioned adjacent to and slightly above / upstream of the mouth of each power nozzle. In operation, it is believed that a portion of fluid flow emanating from the power nozzle is partially or almost completely diverted through the exchange channel, and the main fluid flow will reverse in a regular pattern. As a result, temporary vortices are formed and move within the interaction chamber as fluid flows from the inlet through the outlet (e.g., see Figures 5C-5F), which produces an oscillating spray pattern out of the constriction.Notably, the exchange channel will be narrower along its entire length (i.e., transverse to the expected flow path) compared to the transverse width or axial height of the interaction chamber at its narrowest point.

[0037] Another feature of the fluid geometry is that the major and minor islands may be symmetrical about the centerline axis. Furthermore, the minor island will have a transverse width that is smaller compared to the major island and, since it defines the upper boundary of the interaction chamber, the major island must always have a greater maximum transverse width compared to any portion of the minor island.

[0038] In some aspects, the lowermost edge of the minor island will be substantially or completely flush with or above the lowermost edge of the power nozzle. However, the major island may extend axially below the downstream edge of the minor island (see Figures 3A and 3C). With respect to surface area, the majority (see Figures 3A and 3C) or all (see [Fig. 3B]) of the major island and, separately, all of the minor island will occupy an axial position that is the same as or above the lower / downstream edge of the power nozzles.

[0039] Also, the downstream faces of the interaction chamber will curve from the projection that defines the downstream portion of the power nozzle in a straight horizontal line leading to the outlet. That is, the lowermost wall of the interaction chamber will have walls immediately adjacent both sides of the constriction / outlet that pass along a straight edge orthogonal to the centerline axis of the insert. In one aspect, the horizontal cross-section of each wall is within + / - 10% of the width of the outlet at its narrowest point. In additional aspects, the horizontal cross-section of each wall on the lowermost edge of the interaction chamber passes transversely to a size that is at least the same, up to twice as large, or up to three times as large as the width of the outlet at its narrowest point.

[0040] In some aspects, the widest transverse width of the interaction chamber will be greater than that of the exchange channel (see [Fig. 3B]). In alternative aspects, the exchange channel will have, at its widest point, a transverse width greater than the interaction chamber at its widest point (see Figures 3A and 3C).

[0041] The start-up condition and flow pattern are seen in [Fig.5B]. The circuit will naturally allow one side to start as the dominant outlet flow (represented by the set of arrows on the right side of the drawing, although it will be understood that any number of variables may dictate whether the right or left side of the insert will be dominant at start-up). When the left side flow is obstructed, a portion of the jet from this power nozzle is diverted through the exchange channel as seen in [Fig.5C], with the remaining flow being partially or completely diverted by the dominant stream so as to create a clockwise vortex B in the lower left corner of the interaction chamber.Similarly, as the diverted flow exits the exchange channel, it may merge with the dominant flow and / or drift away to create a clockwise vortex A in the lower right corner of the interaction chamber. Due to the tendency of the fluid flow to attach to or be influenced / impacted by the peripheral wall, vortices A and B will fluctuate in size and intensity. Thus, as seen in [Fig.5D], when vortex A is . large enough, the exit jet, while internal to the interaction region, will be pushed from right to left, reversing the exit jet from the left-side exit to the right-side exit. As a result, the geometry will reverse regularly back and forth, with a corresponding effect and impact on the spray distributed by the exit (i.e., this contributes to the oscillation and variable volume proportion on either side of the spray fan).

[0042] Figures 4D and 5A illustrate that these spray patterns are more uniform (i.e., the volumetric distribution across the fan has less variability) compared to conventional circuits, such as the three-jet island illustrated in Figures 4A and 4C. Of equal importance, the inventive geometries of Figures 3A and 3B (and as otherwise described or contemplated herein) exhibit more consistent performance over wide ranges of temperatures, flow conditions, and fluid types.

[0043] Without wishing to be limited by any particular theory of operation, the inventors believe that the exchange channel may serve as a type of inertance loop. Accordingly, U.S. Patent Publication 2023 / 0355470 and U.S. Patent 9,765,491 are both incorporated by reference herein. Generally, an inertance loop may be employed to create desired flow conditions (e.g., instability and / or oscillations in an exit spray that go along with it). With reference to Figures 5B-5F, adjustments and / or deliberate variations in the length, diameter, height, and / or width of the exchange channel may be made to impact the flow patterns through and emanating therefrom.

[0044] For example, as seen in [Fig.3A], the minor island may extend across the width of the interaction chamber to increase the length of the exchange channel. Axially aligned extensions to this minor island may further extend and lengthen the exchange channel.

[0045] [Fig.3B] represents an alternative or additional way of influencing the inertance effects of the exchange channel. Here, the curvature of the upstream face of the minor island varies compared to the curvature on the downstream face of the major island. This arrangement provides a variable width along the exchange channel, creating the potential for Venturi effects which further influence the flow patterns and vortices described herein.

[0046] [Fig.5E] specifically illustrates this inertance effect. The flow from the right power nozzle (lighter colored arrows) dominates and loops around the interaction chamber (possibly attaching to and / or interacting with features on the downstream face of the minor island). This flow pattern obstructs the less dominant left power nozzle (darker colored arrows) and redirects a flow from the left nozzle down toward the constriction and / or into the exchange channel. Eventually, the opposing power nozzle will overpower the dominant nozzle so that the flows "switch" and follow a regular cycle.

[0047] The flow deflection created by the exchange channel acts as a type of inertance loop, as disclosed in the references set forth above. It is known that inertance loops can be used to tune frequencies in feedback loop geometries, but the inventors are not aware of any similar structure or process provided within the interaction chamber itself, i.e., within the same planar surface, without requiring diverting or redirecting the flow through an orifice in the body or a passage formed in the housing (each meeting at an angle—usually orthogonal—to the planar surface / direction of the inventive geometry). The higher the inertance of the exchange channel, the slower the pressure wave will travel to the other side of the circuit, and the longer the jet will remain at the fan edge position.A lower inertance value of this loop will cause the pressure wave to propagate faster to the other side of the circuit, causing the jet to return to the other side of the fan faster after striking the tip, improving spray uniformity. Therefore, the invention also includes a method of controlling, altering, and fine-tuning the pattern oscillation and spray characteristics produced by the fluidic geometries contemplated herein.

[0048] As shown herein, smooth, symmetrical C-shaped curves may be preferred for the upstream face of the minor island and the downstream face of the major island (as well as the upstream face of the major island, although this face will not play a direct role in the flow patterns and characteristics of the exchange channel). The downstream face of the minor island may also be a smooth, symmetrical C-shaped curve (e.g., [Fig. 3A]), although it may be made a straight line, preferably aligned orthogonally with the centerline axis (e.g., [Fig. 3B]). The transversely opposite ends of the minor island may be inserted from the power nozzle openings (e.g., [Fig. 3B]), or they may align with extensions, fingers, or projections on the peripheral wall that help define the downstream side of the power nozzle ([Fig. 3A]).

[0049] [Fig.3C] provides an example of how the downstream faces of the minor island can be further modified. As shown, small and preferably mirror-image protrusions can be added to these inner faces (effectively creating a serif-style C). Features such as these can help detach fluid flow from the inner walls, particularly under high viscosity conditions. In a similar manner, a protrusion apex (as described in U.S. Patent Publication 2021 / 0114044) may be used as an additional or alternative implementation on the downstream / interaction chamber face of the minor island.

[0050] The major island may, in some cases, be provided with fingers, extensions or projections on the downstream inner faces to define the top / upstream side of the power nozzle ([Fig.3A]). In these cases, the finger / extension / projection helps define the angle and, possibly, the extent to which the jet emanating from this power nozzle will initially be deflected into the exchange channel (rather than entering the interaction chamber).

[0051] Notably, as long as the fluid geometry is based on two opposing power nozzles feeding an interaction chamber, the two-jet island approach contemplated herein may be adapted to work with such geometries (in conjunction with any additive improvements or features associated therewith). As will be understood in this art, a power nozzle necessarily involves the use of a narrowing or constricting flow path so as to create a directed fluid jet that is introduced into the interaction chamber and, as such, a power nozzle is not: a) a simple flow path around an obstruction, and b) the constriction at the outlet of any fluid geometry (insofar as this feature ejects the final spray fan and does not connect to the interaction chamber).

[0052] Notably, none of the power nozzles will be located on the centerline axis (or otherwise positioned on a straight line passing between the inlet and outlet when both the inlet and outlet are located in the central portion of the insert / chip / package). Similarly, the minor island and / or the power nozzles are preferably symmetrical to this centerline axis, meaning that they may form a mirror image with respect to the centerline axis.

[0053] In Figures 2A and 2B, the insert 10 is a cuboid or polygonal body 11 having features sculpted, etched, or formed in one or both of the two major planar faces. One or more inlets are in the form of ports 20a or a plenum 20b (in which the adjacent housing defines and includes the port(s) through which a fluid is introduced into this plenum). These inlets are disposed at an opposite region of the body 11 from the outlet 40.The edges / sides of the body 11, together with portions of the planar faces that might be expected to contact a nozzle housing (not shown), may include inclined, ramped, or specially shaped regions to facilitate such connections, it being further understood that the insert 10 is received in the nozzle housing in a sealed manner such that fluid flows through the inlet 20, through the geometry 30, and is dispensed from the outlet 40 without leakage, loss of . pressure, etc., significant. Notably, the anticipated interlocking / interfacing between the insert 10 and the housing (or other parts of the system) allows for designs in which portions of the peripheral wall, within the geometry 40 or otherwise, may in fact be established by the housing / other parts. Similarly, the open face of the geometry 40 (on one or both sides) will be sealed by corresponding planar faces in the housing / other parts.

[0054] The inlet 20, the geometry 30 and the outlet 40 are defined by a sunken or inserted floor which is defined by peripheral walls (formed by the body 11 and / or the housing). In the region proximate the inlet or inlets, this floor defines a flow passage 21. A series of studs or pillars 22, substantially matching the height of the other obstruction components defining the geometry 30 (i.e., the peripheral walls, the major and minor islands, etc.), may be spaced apart and arranged in a regular line or pattern to act as a filter to prevent debris from entering the geometry 30, thereby reducing the risk of obstructions. The peripheral walls 23 may include notches, guides or other indexing means 24 to ensure that the insert 10 is positioned and nested correctly within the housing. The walls 23 direct a flow from the inlet or inlets 20 to the geometry 30.

[0055] The geometry 30 is defined at its boundaries by curved and / or inclined peripheral walls 37. A major island 32 is positioned in the middle of the floor 31, so that fluid can pass around its outer transverse edges. The floor 31 may include a stepped section 31a that demarcates a transition between the flow passage 21 associated with the inlet 20 and the geometry 30 itself. As seen herein, the floor 31 throughout the geometry will remain within the same common plane. The terminal or opposite transverse ends 32a of the major island 32 define one side (i.e., the upstream edge) of the power nozzles 34, and the ends 32a may include projections or other features as set forth elsewhere herein (e.g., see [Fig. 3C]). The opposite side of the power nozzles 34 will be formed by the walls 37 and, more specifically, by the projections 36b within the interaction chamber 36.In this manner, the power nozzles 34 each direct a jet of fluid toward the opposite / transverse ends of the minor island 33.

[0056] The minor island 33 is spaced apart from but downstream of the major island 32. The island 33 also has the various features and characteristics set forth elsewhere herein, while the passage between islands 32, 33 defines the exchange channel 35. As a result, the channel 35 has opposite ends that are in partial fluid communication with the jets delivered at the outlet by the power nozzles 34 and, separately, with the interaction chamber 36.

[0057] The interaction chamber 36 is free of any obstructions or features (except for the island 32). The chamber 36 will have a common fluidic geometric configuration, having a curved periphery that may define a mushroom, an inverted mushroom, or other shapes. In some aspects, the downstream walls defining the chamber 36 may be orthogonal to the centerline axis AA, although curved and / or inclined sections emanate from the downstream edge of the power nozzles 34 to the outlet 40. The outlet 40 may be defined by a constriction opening in the underside of the interaction chamber 36, having straight edge walls 36a (i.e., passing perpendicular to the centerline axis AA) extending in opposite directions away from the constriction and then curving upward to form opposing projections 36b that define one side (i.e., the downstream edge) of the power nozzles 34.

[0058] In a further aspect illustrated in [Fig.7], it is possible to align each of the edges 33A of the minor island 33 at the downstream edge of the power nozzle 34 (i.e., in alignment with the curvature of the projection 36b) but still within the prescribed distances set forth above (i.e., less than twice the width of the power nozzle and, more preferably, at about the same spacing as the width of the power nozzle). This arrangement effectively directs the majority of the jet from the power nozzles into the exchange channel 35. Here, a radius curved section 36c is positioned in the lower transverse corners of the interaction chamber 36, so as to form a bulbous depression or hollow on the outer edge of each straight wall section 36a.The lowermost edge of the bulbous depression 36c will be positioned closer to the lower edge of the insert (along an axial line) compared to the straight wall section 36a.

[0059] In the aspect of [Fig. 7], this arrangement creates a "flatter" minor island that is more akin to the speed bump of [Fig. 3B], but with a narrower exchange channel 35 whose width remains largely constant along its entire length (i.e., the spacing between the major and minor islands does not vary or, at most, it varies by less than 10% or 5% with the widest section being on the centerline axis). The other features and characteristics of the inventive fluid geometry still apply to this particular aspect.

[0060] An outlet 40 may be positioned on the axis AA on the downstream edge of the body 11. The outlet 40 is characterized by a narrow constriction 41, which joins the downstream walls of the chamber 36. On the opposite edge of the constriction 41, outlet walls 42 diverge from each other to define the outlet 40 which is visible on the edge of the body 11. In some aspects, outlet walls 42 may have individual sections 42a, 42b which are inclined relative to each other. As stated elsewhere herein, it may be possible to provide an additional structural feature in, on or adjacent to the constriction / outlet.

[0061] In view of the foregoing, one aspect of the invention contemplates a fluidic insert for producing an oscillating spray pattern at low temperatures. This insert is formed by a body defining an inlet positioned within an upper portion of the body and an outlet positioned at a lower edge of the body such that a fluid flows in a common spatial plane along a major face of the body from the inlet to the outlet. A major island and a minor island are symmetrically formed on the major face about a centerline axis of the body and wherein the major island: i) is positioned closer to the inlet compared to the minor island, ii) has a lower edge that is spaced from an upper edge of the minor island so as to define an exchange channel, and iii) has a greater maximum transverse width compared to the minor island.An interaction chamber is positioned between the inlet and the outlet and having: i) an upper face defined by a lower edge of the minor island, and ii) a lower face having a pair of straight-edged wall sections emanating in opposite directions from an opening defining the outlet, extending perpendicular to the centerline axis for a wall distance, and thereafter curving axially upward to define opposing projections. Finally, opposing power nozzles defined by the opposing projections and opposing transverse ends of the major island are provided and positioned such that each power nozzle directs a jet of fluid toward opposing transverse ends of the minor island. Additional aspects may include any one or a combination of the following features: . • in which the minor island is a crescent, a C-shape or a speed bump shape; • wherein the opposite transverse ends of the minor island have thickened portions to provide a serif-style C-shape; • wherein the lower edge of the major island is spaced from the upper edge of the minor island at a substantially constant distance along the entire exchange channel; • in which the interaction chamber has an inverted mushroom configuration; • wherein the wall distance is equal to or up to three times greater than an exit distance defined by a narrowest point between the pair of straight-edged wall sections defining the exit; • wherein the opposite transverse ends of the major island are positioned axially closer to the lower edge of the body compared to the opposite projections; • wherein a power nozzle width is defined as a narrowest point between the opposite projection and the opposite transverse end of the major island for each power nozzle, wherein a minor island spacing is defined as a shortest distance between the opposite transverse end of the minor island and the power nozzle associated therewith, and wherein the minor island spacing is less than twice the power nozzle width; • in which a floor formed on the major face has a stepped section between the entrance and the major island; • in which a bulbous depression is interposed between each straight-edged wall section and the projection associated with it.

[0062] A further aspect of the invention is an oscillating spray nozzle comprising any of the aforementioned iterations of the fluidic insert. A method for producing an oscillating spray using any of these inserts is also contemplated. In all of the aforementioned aspects, the oscillating spray so produced will retain its desired characteristics (shape, volumetric distribution, etc.) across a wide range of temperatures and fluid mixtures, including those contemplated in Figures 1B and 1C.Still further, in each of these aspects, fluid from the inlet flows around the two transversely opposite ends of the major island so as to produce a pair of vortices within the interaction chamber that alternate in intensity and / or fluid flows into the exchange channel to create an inertance loop that is alternately fed by only one of the power nozzles and, in either / both cases, the fluid flow patterns create and maintain an oscillating spray in the fluid that is ejected from the outlet.

[0063] As used herein, axial and the axial or lengthwise direction refer to the general direction of flow from the inlet, through the fluid geometry, and as distributed in a spray pattern by the outlet. Thus, by way of single, non-limiting example, the axial direction in Figures 3A-3C coincides with the vertical direction. Therefore, throughout the drawings and this disclosure, the transverse or widthwise direction intersects an axial line at a right angle. In all cases, these and other terms should be read in the context of the disclosure and language commonly used in this art.

[0064] All components must be made of materials having sufficient flexibility and structural integrity, as well as a chemically inert nature and resistance to corrosion and other conditions commonly encountered by exterior vehicle components. Certain grades of injection moldable polymers may be particularly advantageous, as will be various processes for forming detailed shapes in / on blocks of metallic, polymeric, composite, or other types of materials. Additive manufacturing processes may also be useful.

[0065] References to coupling in this disclosure should be understood to encompass any of the conventional means used in this art. This may take the form of snap-fit ​​or force-fitting of components, although threaded fittings, ball and groove and bayonet / slot and flange style assemblies may be employed. Adhesives and fasteners may also be used, although such components should be carefully selected in light of the design considerations set forth above.

[0066] Similarly, an engagement may imply a coupling or an abutting relationship. These terms, as well as any implicit or explicit reference to a coupling, should be considered in the context in which they are used, and any perceived ambiguity may potentially be resolved by reference to the drawings.

[0067] Although the present embodiments have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the invention is not to be limited solely to the disclosed embodiments, and numerous rearrangements, modifications, and substitutions are also contemplated. The exemplary embodiment has been described with reference to the preferred embodiments, but additional modifications and alterations encompass the foregoing detailed description. Such modifications and alterations also fall within the scope of the appended claims or their equivalents.

Claims

Claims

1. A fluidic insert for producing an oscillating spray pattern at low temperatures, the insert comprising: a body defining an inlet positioned within an upper portion of the body and an outlet positioned at a lower edge of the body such that a fluid flows in a common spatial plane along a major face of the body from the inlet to the outlet; a major island and a minor island each formed symmetrically on the major face about a centerline axis of the body and wherein the major island: i) is positioned closer to the inlet compared to the minor island, ii) has a lower edge that is spaced from an upper edge of the minor island so as to define an exchange channel, and iii) has a greater maximum transverse width compared to the minor island;an interaction chamber positioned between the inlet and the outlet and having: i) an upper face defined by a lower edge of the minor island, and ii) a lower face having a pair of straight-edged wall sections emanating in opposite directions from an opening defining the outlet, extending perpendicular to the centerline axis for a wall distance, and thereafter curving axially upward to define opposed projections; and opposed power nozzles defined by the opposed projections and opposed transverse ends of the major island; and wherein the power nozzles each direct a jet of fluid toward opposed transverse ends of the minor island.;

2. The fluidic insert of claim 1 wherein the minor island is a crescent, a C-shape or a speed bump shape.

3. A fluidic insert according to claim 1 or 2, wherein the opposite transverse ends of the minor island have thickened portions to provide a serif-style C-shape.

4. A fluidic insert according to any one of claims 1 to 3 wherein the lower edge of the major island is spaced from the upper edge of the minor island at a substantially constant distance along the entire exchange channel.

5. A fluidic insert according to any one of claims 1 to 4 wherein the interaction chamber has an inverted mushroom configuration.

6. A fluidic insert according to any one of claims 1 to 5 wherein the wall distance is equal to or up to three times greater than an outlet distance defined by a narrowest point between the pair of straight-edged wall sections defining the outlet.

7. A fluidic insert according to any one of claims 1 to 6 wherein the opposite transverse ends of the major island are positioned axially closer to the lower edge of the body compared to the opposite projections.

8. A fluidic insert according to any one of claims 1 to 7 wherein a power nozzle width is defined as a narrowest point between the opposite projection and the opposite transverse end of the major island for each power nozzle, wherein a minor island spacing is defined as a shortest distance between the opposite transverse end of the minor island and the power nozzle associated therewith, and wherein the minor island spacing is less than twice the power nozzle width.

9. A fluidic insert according to any one of claims 1 to 8 wherein a floor formed on the major face comprises a stepped section between the inlet and the major island.

10. A fluidic insert according to any one of claims 1 to 9 wherein fluid from the inlet flows around the two transverse opposite ends of the major island so as to produce a pair of vortices within the interaction chamber and wherein the vortices alternate in intensity so as to create an oscillating spray in the fluid which is ejected from the outlet.

11. A fluidic insert according to any one of claims 1 to 10 wherein the exchange channel serves as an inertance loop which is alternately supplied by only one of the power nozzles so as to maintain an oscillating spray in the fluid which is ejected by the outlet.

12. A fluidic insert according to any one of claims 1 to 11 wherein a bulbous depression is interposed between each straight-edged wall section and the projection associated therewith.

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