Patent Grant
10092913
Field of the Invention
The present invention relates to fluidic circuits and nozzle assemblies configured with fluidic circuit oscillators, and more particularly to fluidic nozzle and circuit assemblies configured to generate a spray for automotive, industrial and consumer applications.
Discussion of the Prior Art
A fluidic nozzle creates a stream of fluid that oscillates within an included angle, known as the fan angle, as illustrated in
The fluid distribution can be important in several applications for fluidic nozzles. In an irrigation nozzle, for example, it is desirable to distribute water evenly over a given area or shape (for example, a quarter circle.) If a heavy-ended fluidic were to be used in such a case, more fluid would be deposited on the edges of the spray, and less in the center. Furthermore, since the trajectory of the droplets is related to droplet size and velocity, the irrigation nozzle will tend to throw water further on the ends than in the middle. Many irrigation nozzle assemblies have spray patterns with several heavy bands.
Another common application for fluidic nozzles is to distribute windshield cleaning fluid across a windshield. In this case, parts of the windshield may be covered with large amounts of wiper fluid, while other parts get only a light coating. In many cleaning applications, it is desirable to distribute fluid as evenly as possible over specific areas.
For contemporary automotive applications (e.g., as discussed generally in applicant's commonly owned U.S. Pat. Nos. 7,014,131, 7,267,290 and 7,651,036) windshield washer nozzles are needed with improved dynamic performance, which means automotive windshield washing system designers want sprays having large droplets delivered at higher velocities to withstand high speeds when the car is in motion. This characteristic is referred to as dynamic performance. Additionally, the spray nozzle needs to work with cold liquid mixtures (e.g., typical windshield washer fluids comprising methanol/ethanol water mixes). This characteristic is referred to as cold performance.
For an illustrative example of how a fluidic oscillator or fluidic circuit might be employed, as shown in applicant's U.S. Pat. No. 7,651,036 and illustrated in
There is a need, therefore, for a durable, reliable and cost effective nozzle structure and fluid distribution or spray generation method to broaden the dynamic and cold performance envelope for nozzle assemblies to be used in automotive, industrial and consumer applications.
Accordingly, it is an object of the present invention to overcome the above mentioned difficulties by providing a durable, reliable and cost effective nozzle structure and fluid distribution or spray generation method to broaden the dynamic and cold performance envelope for nozzle assemblies to be used in automotive, industrial and consumer applications.
Another object of the present invention is to provide a fluidic nozzle and oscillator circuit having improved dynamic and cold performance.
In accordance with the structure and method of the present invention, a fluidic circuit is configured as a nozzle assembly with a fluidic oscillator. Fluidic oscillators or fluidic circuits are often configured for use in housings which define a channel, port or slot that receives and provides boundaries for the fluid paths defined in the fluidic circuit. For an illustrative example of how a fluidic oscillator or fluidic circuit might be employed, as shown in applicant's U.S. Pat. No. 7,651,036,
A nozzle assembly can be configured to include one or more fluidic circuit inserts or chips which are dimensioned to be tightly received in and held by the slot defined within the sidewall of the housing. When the fluidic circuit insert is fitted tightly within the housing's port or slot, the nozzle assembly provides a channel for fluid communication between the housing's interior lumen and the exterior of the housing so that fluid entering the housing's interior lumen may be used to generate an oscillating spray directed distally and aimed by the orientation and configuration of the housing.
The fluidic circuit of the present invention operates on a cyclic jet wall attachment-detachment mechanism resulting in reliable formation of moving vortices which generate a repeatable oscillating jet stream and subsequent spray. Current prototypes of the circuit of the present invention produce a planar spray with a fan angles from 15° to 135°. A 1st embodiment of the fluidic circuit of the present invention has a plurality of sections which cooperate with one another to act upon the flowing fluid passing therethrough to generate internal vortices and a desired oscillating spray. In sequence, fluid initially flows into an inlet which passes through an optional filtering section and then into a power nozzle section, where fluid then passes into a fluid jet-steering vortex generating cavity section. The cavity section's outlet is the inlet for an interaction region which terminates in a throat configured to emit the oscillating spray into the ambient environment.
Prototype embodiments of the fluidic circuit of the present invention is described in terms of certain fluidic oscillator features and dimensions which affect and control the location and formation of circulating vortices which steer fluid flows within an interaction region within the circuit, namely:
Fluid flows or enters through an inlet or feed hole into a rectangular power nozzle lumen, with dimensions Pw and Pd. There is a bell-shaped feed leading to the power nozzle which produces a fluid jet with a turbulent boundary layer that is desirable to form vortices inside an interaction region. In this first embodiment, the fluidic circuit power nozzle provides fluid to a pair of opposing symmetrical fluid vortex-steering cavities, and the size and shape of the cavities can be selected for varying sprays. Seen in plan view, circular or triangular cross section cavities have circulating flow inside them and help steer the vortex by inducing an oscillating instability to the fluid vortex or jet. An optional lateral fluid channel or slot may connect the cavities below the floor of the fluidic. Slot depth is approx. 0.1-0.2 mm below the floor of the circuit. One or more slots are not a requirement for the fluidic to work and are used to make the spray uniform, depending on the application. In many automotive applications, slots are not expected to be needed. The interaction region receives the oscillating jet and generates vortices within the interaction region.
The interaction region's length begins with a narrow channel called a Setback, having the setback width Sw, setback location SL and setback angle length SA. The setback width is critical for the performance of the fluidic. The setback angle length controls the uniformity of the spray, where longer lengths produce a heavy ended spray while shorter lengths produce a uniform spray. It should be noted that SA cannot be increased indefinitely and becomes undesirably monostable for large values of SA. For the Interaction region, critical width and length dimensions IW and IL are sized in relation to the Power nozzle width. These dimensions may be adjusted for packaging constraints. However, dynamic & cold performance are reduced as the interaction region size is reduced below a nominal set of proportions. The Interaction region also includes a symmetrical pair of opposing inwardly projecting features called Ears. Ears cause fluid jet detachment and are critical to the bistable operation of the fluidic.
The circuit operates on a fluid jet wall attachment/detachment cycle. With the jet at the center, large vortices are formed on either or opposing (A or B) sides and the jet attaches to either the A wall or the opposing B wall. Opposing cavities on the A and B sides have varying magnitudes of positive pressure. When cavity B momentarily has a higher pressure than opposing cavity A, the jet bends away from cavity B. Fluid from cavity A replenishes the vortex, which results in jet detaching from the wall and attaching to the other wall. Pressure builds in cavity A until it is greater than pressure in cavity B. The pressure differential causes the jet to detach from wall A and attach to wall B. The cycle then continues from cavity B resulting in an oscillating bistable jet which contributes to generation of an oscillating spray with large fast droplets, when using typical windshield washing fluid. A nozzle assembly with this fluidic exhibits the desired improved dynamic and cold performance.
More broadly, the present invention provides an improved fluidic circuit configured to spray an oscillating pattern of fluid droplets having an inlet in fluid communication with a source and including a power nozzle with an oscillation chamber having a fluid jet steering section in fluid communication with the power nozzle and having either (a) a first fluid pressure accumulating volume opposite a second fluid pressure accumulating volume or (b) a first fluid jet attachment feature opposing a second fluid jet attachment feature. The fluid jet steering section is in fluid communication with and emits a fluid jet into an oscillation inducing interaction region with opposing first and second side walls having features which define an oscillation inducing interaction region in the oscillation chamber for causing reliable formation of moving vortices which force the jet of fluid to rhythmically sweep back and forth between the sidewalls in the oscillation chamber and create a distally projecting oscillating spray.
The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, particularly when taken in conjunction with the accompanying drawings, wherein like reference numerals in the various figures are utilized to designate like components.
Referring now to
The fluidic circuits of the present invention as illustrated in
The 1st embodiment of the fluidic circuit of the present invention 100 as illustrated in
In sequence, fluid initially flows into inlet lumen 110 and then flows through interstitial spaces between an array of inwardly projecting post elements 122 defining an optional filtering section 120 and then into a bell shaped feed terminating distally in a power nozzle 150, where the fluid then passes into a fluid jet-steering cavity section 140. The cavity section's jet outlet is the inlet 161 for a vortex generating interaction region 160 which terminates distally in a throat 180 configured to emit an oscillating spray of fluid droplets into the ambient environment. The spray is a substantially planar oscillating fan aimed in the direction of the fluid flow central axis 102 having a selected fan angle width of greater than 60 degrees.
Fluidic circuit 100 is best described in terms of certain features and structural elements configured with specifically selected dimensions, namely,
In operation, pressurized fluid flows into or enters through an inlet 110 or feed hole into the power nozzle 130 which terminates distally in a rectangular opening with a width dimension (“PW”) and a depth dimension (“PD”). There is a bell-shaped feed 130 leading to the power nozzle 150 which produces an accelerating fluid jet with a turbulent boundary layer that is desirable to form vortices inside interaction region 160. In this first embodiment, the fluidic circuit power nozzle 150 provides fluid to a jet-steering cavity section 140 which includes a first lateral fluid jet-steering cavity 142 opposite a second fluid jet-steering cavity 144, thus providing a pair of opposing, symmetrical fluid jet-steering cavities 142, 144. The size and shape of the cavities is identical, but mirror imaged and can be configured for varying fluid jet steering performance properties.
Seen in the plan view of
The interaction region 160 receives the oscillating jet and the interaction region's interior begins with a narrow channel inlet called a Setback inlet 161, having a selected setback inlet width (“SW”). The flowpath or axial location of Setback Inlet 161 downstream from the power nozzle 150 is called the setback location (“SL”) and setback angle length (“SA”) may be characterized as the flowpath length (or the axial length along axis 102) for the Interaction region's diverging sidewall segments beginning with setback inlet 161. The setback width or lateral width of setback inlet 161 can be used to optimize the performance of fluidic 100 with a variety of fluids. For example, given a PW of 0.5 mm (and with no connecting slot 146), inlet width SW should be greater than 1.35 mm for a bistable operation. For values of SW less than 1.35 mm, the fluidic 100 will not reliably cause or maintain oscillation, (i.e., fluid flow is monostable). However, with a transverse connecting slot 146, a narrower inlet (SW<1.35 mm) is permissible for bistable operation. Thus, for bistable (i.e., oscillating vortex) operation, a wider inlet width (Sw>2.7Pw) works for a prototype circuit with no slot and a slightly narrower inlet (Sw>2Pw) works for circuit with a slot 146.
The setback angle length SA controls the uniformity of the spray, where longer lengths produce a heavy ended spray (similar to that shown in
For the interaction region 160, interaction region width (“IW”) and interaction region length (“IL”) dimensions configured and sized in relation to the width of power nozzle 150, where IW is 6.5 times PW and IL is typically 11 times PW. These values may be adjusted for packaging constraints. However, dynamic & cold performance are reduced as the size of interaction region 160 is reduced below this nominal set of proportions. As best seen in
Critical dimensions for the opening between the tips of ears 162, 164 (“EW”) are:
(a) the lateral width of the inter-ear gap between the inwardly projecting distal ends of the opposing ears, and
(b) the axial length of the fluid's path or channel from the power nozzle 150 to the transverse axis of the inwardly projecting ears (“EL”).
Applicant's experiments have led to the conclusion that proper oscillating (i.e., bistable, rather than monostable) operation is obtained when EW is approx. 5.2 times Pw and EL is in the range of 8.5(PW) to 9.2(PW).
Referring now to
In sequence, fluid initially flows into inlet lumen 210 and then flows through interstitial spaces between an array of inwardly projecting post elements 222 defining an optional filtering section 220 and then into a bell shaped feed 230 terminating in a power nozzle 250, where the fluid then passes into a fluid jet-steering cavity section 240. The cavity section's jet outlet 261 is the inlet for a vortex generating interaction region 260 which terminates distally in a throat 280 configured to emit an oscillating spray of fluid droplets into the ambient environment.
Fluidic circuit 200 is best described in terms of similar features and structural elements configured with specifically selected dimensions, namely,
In operation, pressurized fluid flows into or enters through an inlet 210 or feed hole into the bell shaped feed 230 terminating distally in a rectangular power nozzle opening 250 with a width dimension (“PW”) and a depth dimension (“PD”). The bell-shaped feed 230 leads to power nozzle 250 and which produces an accelerating fluid jet with a turbulent boundary layer that is desirable to form vortices inside interaction region 260. In this second embodiment, the fluidic circuit power nozzle 250 provides fluid to a jet-steering cavity section 240 which includes a first lateral fluid jet-steering cavity 242 opposite a second fluid jet-steering cavity 244, thus providing a pair of opposing, symmetrical fluid jet-steering cavities 242, 244. The size and substantially triangular shape of the cavities is identical, but mirror imaged and can be configured for varying fluid jet steering performance properties.
Seen in the plan views of
The interaction region 260 receives the oscillating jet and the interaction region's interior begins with a narrow channel inlet called a Setback inlet 261, having a selected setback inlet width (“SW”). The flowpath or axial location of Setback Inlet 261 downstream from the power nozzle 250 is called the setback location (“SL”) and setback angle length (“SA”) may be characterized as the flowpath length (or the axial length along axis 202) for the Interaction region's diverging sidewall segments beginning with setback inlet 261. The setback width or lateral width of setback inlet 261 can be used to optimize the performance of fluidic 200 with a variety of fluids. For example, given a PW of 0.5 mm (and with no connecting slot 146), inlet width SW should be greater than 1.35 mm for a bistable operation. For values of SW less than 1.35 mm, the fluidic 100 will not reliably cause or maintain oscillation, (i.e., fluid flow is monostable). However, with a transverse connecting slot (not shown), a narrower inlet (SW<1.35 mm) is permissible for bistable operation. Thus, for bistable (i.e., oscillating vortex) operation, a wider inlet width (Sw>2.7Pw) works for a prototype circuit with no slot and a slightly narrower inlet (Sw>2Pw) works for circuit with a slot. The setback angle length controls the uniformity of the spray, where longer lengths produce a heavy ended spray (similar to that shown in
For the interaction region 260, interaction region width (“Iw”) and interaction region length (“IL”) dimensions configured and sized in relation to the width of power nozzle 250, where Iw is 6.5 times PW and IL is typically 11 times PW. These values may be adjusted for packaging constraints. However, dynamic & cold performance are reduced as the size of interaction region 260 is reduced below this nominal set of proportions. As best seen in
As above, critical dimensions for the opening between the tips of ears 262, 264 (“EW”) are:
(a) the lateral width of the inter-ear gap between the inwardly projecting distal ends of the opposing ears, and
(b) the axial length of the fluid's path or channel from the power nozzle 250 to the transverse axis of the inwardly projecting ears (“EL”).
Applicant's experiments have led to the conclusion that proper oscillating operation is obtained when EW is approx. 5.2 times Pw and EL is in the range of 8.5(PW) to 9.2(PW).
Fluidic circuits 100 and 200 each operate on a jet wall attachment/detachment cycle, as illustrated in
The longer the setback angle length SA, the longer jet 300 dwells at each wall (A side or B side) resulting in a “heavy ended” spray from the throat 280. The inwardly projecting opposing ears (e.g., 262, 264) enable the bistability of the jet oscillation. In absence of the ears, vortex 310 is large (extending the entire length of the interaction region 260) and cannot be adequately replenished, resulting in no wall detachment and monostable operation. Critical ear configuration and placement values (EW and EL) are chosen to optimize cold performance characteristics, (i.e. bistable operation even with washer fluids of higher viscosity). Generally this ranges from 50% methanol-50% water (9 cP) to 50% ethanol-50% water mix (22 cP). Similarly, critical setback dimensions Sw and Sa are chosen for optimized cold performance.
Turning now to
In sequence, fluid initially flows into inlet lumen 410 and then flows through interstitial spaces between an array of inwardly projecting post elements 422 defining an optional filtering section 420 and then into a bell shaped feed terminating distally in a power nozzle 450, where the fluid then passes into a fluid jet-steering section 440. The jet steering section's jet outlet is the inlet 461 for a vortex generating interaction region 460 which terminates distally in throat 480 which is configured to emit an oscillating spray of fluid droplets into the ambient environment.
Fluidic circuit 400 is best described in terms of certain features and structural elements configured with specifically selected dimensions, namely,
Pressurized fluid flows into or enters through an inlet 410 or feed hole into the power nozzle 450 which is preferably a rectangular opening with a width dimension (“PW”) and a depth dimension (“PD”). There is a bell-shaped feed 430 leading to the power nozzle 450 which produces an accelerating fluid jet with a turbulent boundary layer that is desirable to form vortices inside interaction region 460. In this embodiment, the fluidic circuit power nozzle 450 provides fluid to a jet-steering section 440 which includes a first laterally offset fluid jet-steering island 442 opposite a second fluid jet-steering island 444, thus providing a pair of opposing, symmetrical fluid jet-steering islands 442, 444 separated by a central opening defined by the island separation width (“ISW”). The size and shape of the islands is identical, but mirror imaged and can be configured for varying fluid jet steering performance properties.
As best seen in the plan view of
As illustrated in the plan view of
The interaction region 460 receives the oscillating jet and the interaction region's interior begins with a narrowed channel inlet called a Setback inlet 461, having a selected setback inlet width (“SW”). The flowpath or axial location of Setback Inlet 461 downstream from the power nozzle 450 is called the setback location (“SL”) and setback angle length (“SA”) may be characterized as the flowpath length (or the axial length along axis 402) for the Interaction region's angled or diverging first and second sidewall segments beginning with setback inlet 461. The setback width or lateral width of setback inlet 461 can be used to optimize the performance of fluidic 400 with a variety of fluids. For example, given a PW of 0.5 mm and with no connecting slot (e.g. such as transverse slot 146 described for fluidic 100, above), inlet width SW should be greater than 1.35 mm for a bistable operation. For values of SW less than 1.35 mm, the fluidic 400 will not reliably cause or maintain oscillation, (i.e., fluid flow is monostable). However, with a transverse connecting slot 146, a narrower inlet (SW<1.35 mm) is permissible for bistable operation. Thus, for bistable (i.e., oscillating vortex) operation, a wider inlet width (Sw>2.7Pw) works for a prototype circuit with no slot and a slightly narrower inlet (Sw>2Pw) works for circuit with a slot (e.g., 146). The setback angle length controls the uniformity of the spray, where longer lengths produce a heavy ended spray (similar to that shown in
For the interaction region 460, interaction region width (“IW”) and interaction region length (“IL”) dimensions configured and sized in relation to the width of power nozzle 450, where IW is 6.5 times PW and IL is typically 11 times PW. These values may be adjusted for packaging constraints. However, dynamic & cold performance are reduced as the size of interaction region 460 is reduced below this nominal set of proportions. As best seen in
Critical dimensions for the opening between the tips of ears 462, 464 (“EW”) are:
(a) the lateral width of the inter-ear gap between the inwardly projecting distal ends of the opposing ears, and
(b) the axial length of the fluid's path or channel from the power nozzle 450 to the transverse axis of the inwardly projecting ears (“EL”).
Applicant's experiments have led to the conclusion that proper oscillating operation is obtained when EW is approx. 5.2 times Pw and EL is in the range of 8.5(PW) to 9.2(PW).
In the illustrated embodiment for circuit 400, proper operation was confirmed when the following relationships were maintained: Isw=1.2Pw−1.3Pw and Sw=3.5Pw−3.8Pw.
For the embodiment of
Turning now to the nozzle assembly insert embodiment illustrated in
Turning now to
In sequence, fluid initially flows into inlet lumen slot 910 and then flows through interstitial spaces between the array of inwardly projecting post elements 922 defining optional filtering section 920 and then into a bell shaped feed terminating distally in a power nozzle 950, where the fluid then passes into a fluid jet-steering section 940. The jet steering section's jet outlet is the inlet 961 for a vortex generating interaction region 960 which terminates distally in split throat 980 which is configured to emit an oscillating spray of fluid droplets into the ambient environment.
Fluidic circuit 900 is best described in terms of certain features and structural elements configured with specifically selected dimensions, namely,
Pressurized fluid flows into or enters through an inlet 910 or feed hole into the power nozzle 450 which is preferably a rectangular opening with a width dimension (“PW”) and a depth dimension (“PD”). Bell-shaped feed 930 leads to the power nozzle 950 which produces an accelerating fluid jet with a turbulent boundary layer that is desirable to form vortices inside interaction region 960. In this embodiment, the fluidic circuit power nozzle 950 provides fluid to jet-steering section 940 which includes a first laterally offset fluid jet-steering island 942 opposite a second fluid jet-steering island 944, thus providing a pair of opposing, symmetrical fluid jet-steering islands 942, 944 separated by a central opening defined by the island separation width (“ISW”). The size and shape of the islands is identical, but mirror imaged and the islands can be configured for varying fluid jet steering performance properties.
First island 942 is laterally offset from central axis 902 along the fluid flow path and spaced from a first curved fluid jet steering interaction region sidewall segment 952 which defines a first jet steering lumen and extends from a first side the power nozzle 950 to a first side of the inlet of the interaction region 960 and is contiguous with a first angled sidewall segment of the interaction region 960. Symmetrically, a second island 944 is laterally offset from central axis 902 along the fluid flow path and spaced from a second curved fluid jet steering interaction region sidewall segment 954 which defines a second jet steering lumen and extends from a second side of power nozzle 950 to the inlet of a second side the interaction region 960 and is contiguous with a second angled sidewall segment of the interaction region 960 which thereby defines an oscillation chamber. Fluid jet steering section 940 thus comprises a first fluid jet steering lumen proximate first island 942 which defines a first fluid pressure accumulating volume opposite the second fluid jet steering lumen proximate second island 944 to define a second fluid pressure accumulating volume. The first fluid jet steering lumen and said second fluid jet steering lumen are thus in fluid communication with one another and with power nozzle 950, and the fluid jet steering section 940 is in fluid communication with and emits a fluid jet into the oscillation inducing interaction region 960 which functions as an oscillation chamber.
Seen in the plan view of
The interaction region 960 receives the oscillating jet and the interaction region's interior begins with a narrowed channel inlet called a Setback inlet 961, having a selected setback inlet width (“SW”). The flowpath or axial location of Setback Inlet 961 downstream from the power nozzle 950 is called the setback location (“SL”) and setback angle length (“SA”) may be characterized as the flowpath length (or the axial length along axis 902) for the Interaction region's angled or diverging first and second sidewall segments beginning with setback inlet 961. The setback width or lateral width of setback inlet 961 can be used to optimize the performance of fluidic 900 with a variety of fluids. For example, given a PW of 0.5 mm and with no connecting slot (e.g. such as transverse slot 146 described for fluidic 100, above), inlet width SW should be greater than 1.35 mm for a bistable operation. For values of SW less than 1.35 mm, the fluidic 400 will not reliably cause or maintain oscillation, (i.e., fluid flow is monostable). However, with a transverse connecting slot (e.g., like 146, but not shown), a narrower inlet (SW<1.35 mm) is permissible for bistable operation. Thus, for bistable (i.e., oscillating vortex) operation, a wider inlet width (Sw>2.7Pw) works for a prototype circuit with no slot and a slightly narrower inlet (Sw>2Pw) works for circuit with a slot (e.g., 146). The setback angle length controls the uniformity of the spray, where longer lengths produce a heavy ended spray (similar to that shown in
For the interaction region 960, interaction region width (“Iw”) and interaction region length (“IL”) dimensions configured and sized in relation to the width of power nozzle 450, where Iw is 6.5 times PW and IL is typically 11 times PW. These values may be adjusted for packaging constraints. However, dynamic & cold performance are reduced as the size of interaction region 960 is reduced below this nominal set of proportions. The interaction region 960 also includes a symmetrical pair of opposing inwardly projecting substantially triangular sectioned ears 962, 964, which each project from a wider proximal base and terminate distally in a radiussed tip. Ears 962, 964 are preferably equal in size and are aligned along a transverse axis at a position which is downstream from the setback inlet 961 of interaction region 960. Absence of ears 962, 964 makes the circuit 900 monostable.
Critical dimensions for the opening between the tips of ears 962, 964 (“EW”) are:
(a) the lateral width of the inter-ear gap between the inwardly projecting distal ends of the opposing ears, and
(b) the axial length of the fluid's path or channel from the power nozzle 450 to the transverse axis of the inwardly projecting ears (“EL”).
Applicant's experiments have led to the conclusion that proper oscillating operation is obtained when EW is approx. 5.2 times Pw and EL is in the range of 8.5(PW) to 9.2(PW).
In the illustrated embodiment for circuit 400, proper operation was confirmed when the following relationships were maintained: Isw=1.2Pw−1.3Pw and Sw=3.5Pw−3.8Pw.
For the embodiment of
Split throat owl fluidic circuit 900 can be used with a splitter at the throat for sprays with larger fan angles. Generally, for sprays with larger fan angles (e.g., >60°) the fluidic configuration of
Persons of skill in the art will appreciate that the embodiments described and illustrated thus far provides a fluidic circuit (e.g., 100, 200, 400, 800 or 900) adapted for use in a nozzle assembly and configured to spray an oscillating pattern of fluid droplets, comprising a source of fluid under pressure (not shown), a fluidic oscillator (e.g., 100, 200, 400, 800 or 900) having an inlet in fluid communication with the source and including a power nozzle, said oscillator further including an oscillation chamber having an upstream end with an inlet coupled to said power nozzle for issuing a jet of fluid into the oscillation chamber and a downstream end having an outlet aperture or orifice (e.g., 180, 280, 480) for issuing a jet of fluid into ambient space. The oscillation chamber has a fluid jet steering section (e.g. 140, 240, 440 or 940) in fluid communication with the power nozzle and having a first fluid pressure accumulating volume opposite a second fluid pressure accumulating volume, each in fluid communication with one another and with the power nozzle, where the fluid jet steering section is in fluid communication with and emits a fluid jet into an oscillation inducing interaction region. The oscillator further includes opposing first and second side walls which intersect opposing the top and bottom walls to define the oscillation inducing interaction region in the oscillation chamber for causing the jet of fluid to rhythmically sweep back and forth between the sidewalls in the oscillation chamber, and the oscillation inducing interaction region defines the throat width and the power nozzle width, while the upstream end comprises a tapering or narrowing (preferably bell-shaped) feed (e.g., 130, 230, 430) that promotes the spreading of the jet as it leaves the power nozzle; wherein the interaction region and the fluid jet steering section are quickly filled with fluid from said source and the fluidic oscillator is activated to provide a bistable, oscillating spray.
The fluidic nozzle oscillation chamber's interaction region preferably includes opposing ear-shaped protuberances (e.g., 162, 164) projecting inwardly from the opposing first and second side walls, and the oscillation chamber's fluid jet steering section may comprise a first cavity (e.g., 142 or 242) defining a first fluid pressure accumulating volume opposite a second cavity (e.g., 144 or 244) defining a second fluid pressure accumulating volume, where the first cavity and the second cavity are in fluid communication with one another and with the power nozzle. The fluid jet steering section may have first and second opposing jet steering lumens or channels defined around first and second islands (442, 444) to provide fluid pressure accumulating volumes (instead of opposing cavities). The fluid jet steering section is in fluid communication with and emits a fluid jet into an oscillation inducing interaction region. The first cavity defining the first fluid pressure accumulating volume may be configured with a substantially circular cross section (e.g., 142) or with a substantially triangular cross section (e.g., 242).
Referring now to
As illustrated in
Improved fluidic oscillator 1100 may be readily configured for insertion into a nozzle housing (e.g., 10) to provide an improved nozzle configured to spray an oscillating pattern of fluid droplets once connected to and supplied by a source of fluid under pressure. Fluidic oscillator 1100 is preferably defined in a fluid impermeable substrate and having an inlet 1110 in fluid communication with the source and including a power nozzle 1150 in fluid communication with oscillation chamber 1160 having an upstream end with an inlet coupled to power nozzle 1150 for issuing a jet of fluid into oscillation chamber 1160 and a downstream end having an outlet aperture 1180 for issuing the jet of fluid (e.g., like 300 or 500) into ambient space. Oscillation chamber 1160 defines a fluid jet steering section in fluid communication with power nozzle 1150 and having a first fluid jet steering sidewall feature 1142B defined in left sidewall 1142 opposite a second fluid jet steering sidewall feature 1144B defined in right sidewall 1144, each in fluid communication with one another and with power nozzle 1150, so the fluid jet steering section is in fluid communication with and emits a fluid jet into the oscillation inducing interaction region.
As with the fluidic geometries described above, oscillator 1100 further includes and opposing first and second side walls which intersect opposing top and bottom walls to define the oscillation inducing interaction region in the oscillation chamber, and the opposing first and second sidewalls 1142, 1144 diverge in linear wall segments which then diverge in arcuate or concave symmetrical round bowl-shaped segments (e.g., curved opposing sidewall segments) which define laterally opposing first and second setback features 11428, 11448 for causing a jet attached to the wall to detach and thereby cause the jet of fluid to develop alternating (left and right side) circulating vortices which grow (in circulation diameter) and move distally toward exit throat 1180 and thus force the fluid jet to rhythmically sweep back and forth between those sidewalls in the oscillation chamber. Oscillation inducing interaction region 1160 defines a throat width TW and a power nozzle width PW and the oscillation chamber's upstream end comprises a bell-shaped feed 1130 that promotes the spreading of the jet as it leaves the power nozzle 1150.
In use, interaction region 1160 and particularly fluid jet steering section 1140 are quickly filled with fluid from the inlet 1110 and fluidic oscillator 1100 is activated to generate a bistable oscillating spray of droplets in a selected fan pattern. Fluid jet vortex creation and movement are enhanced by opposing ear-shaped protuberances 1162 and 1164 which projecting inwardly from the opposing first and second side walls to create jet steering vortices. The sidewalls of interaction region 1160 terminate distally with symmetrical opposing semi-cylindrical sidewall sections 1172, 1174 which are configured to receive each side's vortices, once they have traveled distally past the ears 1162, 1164.
For purposes of providing a definite nomenclature, it is noted that
Turning now to
The slot-bump fluidic circuit 1200 as illustrated in
In sequence, fluid initially flows into inlet lumen 1210 and then (preferably) flows through interstitial spaces between an array of inwardly projecting post elements 1222 defining an optional filtering section 1220 and then into a bell shaped feed 1230 terminating distally in a power nozzle 1250, where the fluid then passes into a fluid jet-steering attachment wall section 1240 which defines an expanding cross sectional area through which the fluid (including fluid jet 1300 flows). Attachment wall section 1240 comprised region between the laterally opposed diverging wall segments 1242, 1244 which diverge along the central flow axis 1202 at an included acute sidewall to sidewall divergence angle (between opposing diverging walls 1242 and 1244) of less than 60 degrees and, preferably 40 degrees, meaning the preferred angle IA between each diverging sidewall and central axis 1202 is 20 degrees (as illustrated in
Returning to
As with the embodiments described above, fluidic circuit 1200 is best described in terms of certain features and structural elements configured with specifically selected dimensions, namely,
PW=Width of Power Nozzle 1250,
PD=Depth of Power Nozzle 1250,
Tw=Width of Throat 1280,
Td=Depth of Throat 1280,
IW=Width of Interaction Region 1260,
IL=Axial Length of Interaction Region 1260,
Ew=InterEar Gap Width between Ears 1262, 1264,
EL=Axial Location of inwardly projecting tips of Ears 1262, 1264,
Sw=Channel Width at Setback Slot upstream end 1261,
SL=Axial Length of Setback Slot upstream end 1261 and
FL=Setback or concavity (e.g., slot end) Feature Length, or axial length of Interaction region's diverging sidewall setback or concavity feature from the interaction chamber inlet to the widest portion of laterally opposing first and second setback features 1242B, 1244B (as illustrated in
SAL=Sidewall Angle Segment Length, or axial length of Interaction region's diverging sidewall segments from the interaction chamber inlet to the ears 1262, 1264.
In operation, pressurized fluid flows into or enters through inlet 1210 or feed hole into the power nozzle 1230 which terminates distally in a rectangular opening with a width dimension (“PW”) and a depth dimension (“PD”). Bell-shaped feed 1230 provides fluid to power nozzle 1250 which produces an accelerating fluid jet 1300 with a turbulent boundary layer that is desirable to form vortices inside interaction region 1260 (as illustrated in
Seen in the plan view of
The interaction region 1260 receives the oscillating jet and the interaction region's interior geometry begins with an expanding channel segment between diverging walls 1242, 1244 terminating in a setback 1261 (see
For the interaction region 1260, interaction region width (“Iw”) and interaction region length (“IL”) dimensions are configured and sized in relation to the width of power nozzle 1250, where Iw is preferably 9.6 times PW and IL is preferably 12.2 times PW. These values may be adjusted for packaging constraints. However, dynamic & cold performance are reduced as the size of interaction region 1260 is reduced below this nominal set of proportions. Preferably, Setback Feature Length FL is configured to be less than or equal to 4*Pw, to maintain the fluidic's bistable oscillating performance. As best seen in
Critical dimensions for the opening between the tips of ears 1262, 1264 (“EW”) are: (a) the lateral width of the inter-ear gap between the inwardly projecting distal ends of the opposing ears, and (b) the axial length of the fluid's path or channel from the power nozzle 1250 to the transverse axis of the inwardly projecting ears (“EL”) as best seen in
One prototype fluidic oscillator configured as illustrated in
In the method of the present invention, fluid flows are steered by forming and moving circulating vortices within the interaction region of a fluidic oscillator. The formation and movement of those vortices within interaction region 1260 and the method for generating and maintaining laterally sweeping oscillating spray 1300J is best described and illustrated in the time sequential views of
Continuing, another moment later in time, the operation of fluidic 1200 is illustrated in
Another moment later in time, the operation of fluidic 1200 is illustrated in
Improved fluidic oscillator 1200 may also be readily configured for insertion into a nozzle housing (e.g., 10) to provide an improved nozzle configured to spray an oscillating pattern of fluid droplets once connected to and supplied by a source of fluid under pressure. Fluidic oscillator 1200 is preferably defined in a fluid impermeable substrate and having an inlet 1210 in fluid communication with the source and including a power nozzle 1250 in fluid communication with oscillation chamber 1260 having an upstream end with an inlet coupled to power nozzle 1250 for issuing a jet of fluid into oscillation chamber 1260 and a downstream end having an outlet aperture 1280 for issuing the jet of fluid 1300J into ambient space. Oscillation chamber 1260 defines a fluid jet steering section 1240 in fluid communication with power nozzle 1250 and having a first fluid jet steering sidewall feature 1242 opposite a second fluid jet steering sidewall feature 1244, each in fluid communication with one another and with power nozzle 1250, so the fluid jet steering section is in fluid communication with and emits a fluid jet 1300 into the oscillation inducing interaction region 1260.
As with the fluidic geometries described above, oscillator 1200 further includes and opposing first and second side walls which intersect opposing top and bottom walls to define the oscillation inducing interaction region in the oscillation chamber, and the opposing first and second sidewalls 1242, 1244 diverge in linear wall segments which then diverge further in concave symmetrical slot-end shaped segments which define laterally opposing first and second setback features 1242B, 1244B for causing a jet attached to the wall to detach and thereby cause the jet of fluid to develop vortices which grow and force the jet to rhythmically sweep back and forth between those sidewalls in the oscillation chamber. Oscillation inducing interaction region 1260 defines a throat width TW and a power nozzle width PW and the oscillation chamber's upstream end comprises a bell-shaped feed 1230 that promotes the spreading of the jet as it leaves the power nozzle 1250.
In use, interaction region 1260 and particularly fluid jet steering section 1240 are quickly filled with fluid from the inlet 1210 and fluidic oscillator 1200 is activated to generate a bistable oscillating spray. Fluid jet vortex creation and movement are illustrated in
For purposes of providing a definite nomenclature, it is noted that
Persons of skill in the art will appreciate that the embodiments described and illustrated in
Having described preferred embodiments of a new and improved structure and method, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention.
This application is claims priority to commonly owned (a) U.S. provisional patent application No. 62/120,969 entitled Double-bowl and bump-slot fluidic oscillator circuits and fluidic nozzle assemblies and method for generating sprays with enhanced cold performance, filed on Feb. 26, 2015, (b) U.S. provisional patent application No. 61/736,306, filed Dec. 12, 2012, and (c) PCT Application no. PCT/US13/74603, filed Dec. 12, 2013, both entitled Fluidic Nozzle and Oscillator Circuit, the entire disclosures of which are incorporated herein by reference. This application is also related to commonly owned U.S. patent application Ser. Nos. 12/314,242 and 12/467,270 as well as commonly owned with related U.S. Pat. Nos. 4,463,904, 7,014,131, 7,267,290 and 7,651,036, the entire disclosures of which are also incorporated herein by reference.
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| Number | Date | Country | |
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| Number | Date | Country | |
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| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2013/074603 | Dec 2013 | US |
| Child | 14738024 | US |
