Fluidic oscillator and spray-forming output chamber

Abstract

A fluidic oscillator includes a chamber having a common inflow and outflow opening into which a jet is issued in a generally radial direction. After impinging upon the far chamber wall the jet is redirected to form a vortex on each side of the incoming jet. The vortices alternate in strength and position to direct outflow through the common opening along one side and then the other of the inflowing jet. A spray-forming output chamber is arranged to receive the pulsating outflows from the aforementioned or other fluid oscillator and establish an output vortex which is thereby alternately spun in opposite directions. An outlet opening from the output chamber issues fluid in a sweeping spray pattern determined by the vectorial sum of a first vector, tangential to the output vortex and a function of the spin velocity, and a second vector, directed radially from the vortex and determined by the static pressure in the chamber. By increasing or decreasing the static pressure, or by increasing or decreasing the vortex spin velocity, the angle subtended by the sweeping spray can be controlled over an unusually large range. By properly configuring the oscillator and/or output chamber, concentrations and distribution of fluid in the spray pattern can be readily controlled.

I claim: .[.1. A fluid oscillator comprising; 
     
        out of said chamber through said common inlet and outlet opening..]. 2. .[.The oscillator according to claim 1.]. .Iadd.A fluid oscillator comprising: nozzle means for forming and issuing a jet of fluid in response to application thereto of fluid under pressure;   an oscillation chamber having a substantially central region and a common inlet and outlet opening, said oscillation chamber being positioned to receive said jet of fluid from said nozzle means through said common opening, said oscillation chamber including: oscillation means for cyclically deflecting said jet from side to side in said chamber in a direction substantially transverse to the direction of flow in said jet; and   flow directing means for directing fluid from the cyclically oscillated jet out of said chamber through said common inlet and outlet opening along both sides of said jet such that less flow always egresses along the side toward which said jet is deflected than along the opposite side; .Iaddend.     wherein said oscillation means comprises impingement means .[.,.]. disposed in said oscillation chamber in the path of said jet .[.,.]. for forming.[., on each side of said jet,.]. .Iadd.two .Iaddend.vortices of said jet fluid which .[.alternate in both strength and chamber position.]. .Iadd.remain in said oscillation chamber during oscillation, one vortex on each side of said jet, said impingement means comprising: means for alternating the strengths of said vortices .Iaddend.in phase opposition.Iadd., and for moving said vortices, in phase operation, between positions proximate said common opening and said central   
     
     
        region.Iaddend.. 3. The oscillator according to claim 2 wherein said impingement means comprises a far wall of said chamber remote from said common inlet and outlet opening .Iadd.and devoid of discontinuities which 
     
     
        project into said chamber.Iaddend.. 4. The oscillator according to claim 3 wherein said flow directing means comprises said far wall and opposing 
     
     
        sidewalls of said chamber. 5. The oscillator according to claim 4 wherein said nozzle means is positioned to issue said jet generally radially across said oscillation chamber toward said far wall, and wherein said common inlet and outlet opening is defined as a space between said opposed 
     
     
        sidewalls. 6. The oscillator according to claim 4 further comprising: a first outlet passage positioned at one side of said nozzle means to receive fluid flowing out of said common inlet and outlet opening along said one side of said jet; and   a second outlet passage positioned at the opposite side of said nozzle means to receive fluid flowing out of said common inlet and outlet opening   
     
     
        along said opposite side of said jet. 7. The oscillator according to claim 6 wherein at least one of said outlet passages is bifurcated. .[.8. The oscillator according to claim 6 further comprising: an output chamber;   means connecting said first outlet passage to said output chamber for delivering fluid from said first outlet passage into said output chamber in a first vortical flow direction;   means connecting said second outlet passage to said output chamber for delivering fluid from said second outlet passage into said output chamber in a second vortical flow direction;   whereby in said output chamber an output vortex is established which alternately spins in one direction in response to inflow from said first outlet passage and in the opposite direction in response to inflow from said second outlet passage; and   outlet opening means defined in said output chamber and communicating with ambient environment for issuing from said output chamber a cyclically sweeping flow pattern..]. .[.9. The oscillator according to claim 8 wherein said output chamber is formed between a pair of converging walls which terminate in spaced relation to define said outlet opening means..]. .[.10. The oscillator according to claim 8 wherein said outlet opening means includes a plurality of individual openings from said output chamber..]. .[.11. The oscillator according to claim 8 wherein said output chamber is defined in part by a ceiling, a floor and a continuous wall extending between said outlet passages and wherein said outlet opening means comprises at least one opening defined in one of said ceiling and floor..]. .[.12. The oscillator according to claim 8 wherein said nozzle means comprises a member disposed between said oscillation chamber and said output chamber, said member including a nozzle for issuing said jet at its upstream end and a further wall constituting part of said output chamber periphery at its downstream end..]. .[.13. The oscillator according to claim 12 wherein said further wall is substantially concave..]. .[.14. The oscillator according to claim 12 wherein said further wall is substantially straight..]. .[.15. The oscillator according to claim 12 wherein said further wall is convex..]. .[.16. The oscillator according to claim 12 further comprising additional nozzle means in said member for issuing said applied fluid under pressure directly into said output chamber..]. .[.17. The oscillator according to claim 12 wherein   
     
     
        said output chamber is substantially rectangular..]. .[.18.  The oscillator according to claim 12 wherein said oscillation chamber includes first and second sidewalls which extend from said far wall in said oscillation chamber to beyond said member to constitute first and second sidewalls, respectively, of said output chamber..]. .[.19. The oscillator according to claim 18 wherein said first and second outlet passages are defined between said member and the portions of said first and second sidewalls, respectively, which extend between said oscillation and output chambers..]. .[.20. The oscillator according to claim 19 wherein said first and second sidewalls converge throughout the length of said output chamber towards said outlet opening means..]. .[.21. The oscillator according to claim 19 wherein said first and second sidewalls in said output chamber first diverge and then converge in a downstream direction..]. .[.22. The oscillator according to claim 19 wherein said first and second sidewalls are substantially parallel throughout the length of said output chamber..]. .[.23. The oscillator according to claim 19 wherein said first and second sidewalls in said output chamber converge toward the downstream end of said chamber, and wherein said outlet opening means comprises at least one outlet opening defined between the converging first and second sidewalls..]. .[.24. The oscillator according to claim 23 wherein said output chamber is further enclosed between top and bottom walls extending generally perpendicular to said first and second sidewalls..]. .[.25. The oscillator according to claim 24 wherein the depth dimensions of said output chamber between said top and bottom walls is greater than the depth of said first and second outlet passages..]. .[.26. The oscillator according to claim 25 wherein said outlet opening means comprises a slot defined through periphery of said output chamber, said slot being longer in its dimension parallel to the depth of said output chamber than in its width dimension extending between said first and second sidewalls..]. .[.27. The oscillator according to claim 25 wherein said outlet opening means comprises an outlet opening defined in at least one of said ceiling and floor..]. .[.28. The oscillator according to claim 27 wherein said outlet opening is defined substantially centrally in said output chamber..]. .[.29. The oscillator according to claim 28 wherein said output chamber tapers in its depth dimension toward outlet opening..]. .[.30. The oscillator according to claim 27 wherein said outlet opening is a slot disposed off-center in said output chamber..]. .[.31. The oscillator according to claim 24 wherein said outlet opening means includes a notch cut into the output chamber entirely through said top and bottom walls..]. .[.32. The oscillator according to claim 19 wherein said first and second sidewalls in said output chamber first diverge and then converge toward said outlet opening means, and wherein said first and second sidewall slightly upstream of said output chamber converge to define an entry throat to said output chamber..]. .[.33. The oscillator according to claim 8 further comprising means for expanding the fluid flow pattern issuing from said outlet opening means in a direction normal to the sweep direction in said cyclically sweeping flow pattern..]. .[.34. The oscillator according to claim 8 further comprising means in said output chamber for issuing said cyclically sweeping flow pattern in a generally fan-shaped spray subsisting substantially in a common plane with 
     
     
        said output vortex..]. .[.35.  The oscillator according to claim 8 further comprising means for issuing said cyclically sweeping flow pattern as a cyclically swept fluid sheet extending significantly out of the plane of 
     
     
        the output vortex..]. 36. The oscillator according to claim 5 wherein said oscillation chamber is generally circular, said common inlet and outlet 
     
     
        opening subtending an arc on the oscillation chamber periphery. 37. The oscillator according to claim 36 wherein said arc is greater than 
     
     
        180°. 38. The oscillator according to claim 36 wherein said arc is 
     
     
        less than 180°. 39. The oscillator according to claim 36 wherein 
     
     
        said arc is substantially equal to 180°. 40. The oscillator according to claim 5 wherein said oscillator chamber is generally 
     
     
        rectangular. 41. The oscillator according to claim 5 wherein said far wall 
     
     
        in said oscillation chamber is substantially flat. 42. The oscillator according to claim 41 wherein the sidewalls of said oscillation chamber diverge from said far wall toward said common inlet and outlet opening. 
     
     
            The oscillator according to claim 5 wherein said far wall is concave. .[.44. The oscillator according to claim 5 wherein said far wall is 
     
     
        convex..]. 45. The oscillator according to claim 5 further comprising first and second members disposed proximate said common inlet and outlet opening from said nozzle means, each member being disposed .[.on.]. .Iadd.of .Iaddend.a .[.negative.]. .Iadd.represective .Iaddend.side of the 
     
     
        jet issued from said nozzle means. 46. The oscillator according to claim 6 disposed in a flowing fluid to measure the flow thereof, said flowing fluid corresponding to the fluid under pressure applied to said nozzle means, said oscillator further comprising sensing means for monitoring 
     
     
        cyclic variations of a flow parameter in said chamber. 47. The oscillator according to claim 46 wherein said sensing means comprises a pair of pressure ports defined in said far wall, said pressure ports being 
     
     
        symmetrically positioned with respect to said nozzle means. 48. The oscillator according to claim 46 wherein said sensing means comprises means for measuring cyclic flow variation in at least one of said outlet 
     
     
        passages. 49. The oscillator according to claim 46 wherein said first and second outlet passages are curved to issue fluid in the same flow 
     
     
        direction as said flowing fluid. 50. The oscillator according to claim 46 wherein said nozzle means has an inlet end which is streamlined and positioned to face directly upstream in said flowing fluid, and wherein said outlet passages are positioned to be aspirated by said flowing fluid. .[.51. A spray-forming device comprising: means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from said first and second fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions about a spin axis in response to inflowing of said first and second fluid flows to said chamber; and   outlet means displaced from said spin axis for providing an outflow flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second   
     
     
        directions respectively..]. .[.52.  The device according to claim 51 wherein said outlet means includes an opening in the periphery of said chamber which communicates between the chamber interior and ambient environment..]. .[.53. The device according to claim 51 wherein said outlet means comprises means for issuing fluid from said chamber at a velocity which is the vectorial sum of a first vector directed tangentially to said output vortex at said outlet means and a second vector directed radially outward from said output vortex, said first vector being determined by the spin velocity of said vortex at said outlet means, said second vector being determined by the static pressure at said outlet means..]. .[.54. The device according to claim 53 wherein said outlet means comprises an opening in the periphery of said chamber which communicates between the chamber interior and ambient environment..]. .[.55. The device according to claim 54 wherein said chamber has top and bottom walls and sidewalls, said output vortex being constrained to flow in a plane which is substantially parallel to at least one of said top and bottom walls..]. .[.56. The device according to claim 55 wherein said outlet means comprises an opening in one of said top and bottom walls..]. .[.57. A spray-forming device comprising: means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively, said outlet means comprising means for forming said output flow into a sheet of fluid expanding normal to the direction in which said output flow is cyclically swept..]. .[.58. A spray-forming device comprising:   means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively, said chamber being between first and second sidewalls which converge toward said outlet means..]. .[.59. A spray-forming device comprising:   means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively, said first and second fluid repetitive flows comprising first and second pulse trains, the device further comprising first and second flow dividers positioned in the paths of said first and second pulse trains, respectively, to divide the fluid pulses into two separate pairs, said flow dividers each having curved walls shaped to direct the divided pulse flows rotationally in said chamber..]. .[.60. A spray-forming device comprising:   means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions in said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows in said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively;   said chamber being semi-spherical and said means for directing first and second fluid flows comprising first and second substantially co-planar flow passages arranged to issue said first and second fluid flows in opposite tangential directions into said chamber, and wherein said outlet means includes an opening from said chamber to ambient residing in the plane of said first and second flow passages..]. .[.61. The device according to claim 60 further comprising third and fourth co-planar flow passages residing in a second plane other than that of said first and second flow passages and including said opening therein and arranged to issue respective third and fourth fluid flows in opposite tangential directions into said chamber..]. .[.62. The device according to claim 61 wherein said second plane is perpendicular to the plane of said first and second flow passages..]. .[.63. The device according to claim 62 wherein said first and second fluid flows comprise first and second pulse trains equal in frequency and displaced in phase by 180° and said third and fourth fluid flows comprise third and fourth pulse trains equal in frequency and displaced in phase by 180°..]. .[.64. The device according to claim 63 wherein the frequencies of said first and third pulse trains are equal but displaced in phase by 90°..]. .[.65. The device according to claim 63 wherein the frequencies of said first and second pulse trains are twice the frequency of said third and fourth pulse   
     
     
        trains..]. .[.66.  The method providing an oscillating fluid flow comprising the steps of: issuing a fluid jet into a chamber through a common opening to impinge upon a wall of said chamber;   dividing the impinging jet into two oppositely recirculating vortical flow patterns, one on each side of said jet, which increase and decrease in size in phase opposition;   and .[.alternately.]. flowing fluid from said two vortical flow patterns out of said chamber through said common opening..]. .[.67. A device for spraying liquid comprising:   a body member;   an inlet for receiving pressurized liquid into said body member;   first and second outlet openings for issuing pressurized liquid from said body member in predetermined general directions into ambient environment; and   sweeping means inside said body member for sweeping the liquid issued from said outlet openings back and forth transversely of said predetermined general directions to provide two simultaneous swept spray patterns..]. .[.68. The device according to claim 67 wherein said means comprises:   means for providing first and second repetitive fluid signals of varying amplitudes and different phases;   a chamber;   means for directing said first and second fluid signals into said chamber in opposite generally tangential directions; and   means forming a vortex in said chamber from the fluid supplied from said first and second fluid signals, said vortex alternately spinning clockwise and counter-clockwise in response to said first and second fluid signals, respectively;   wherein said first and second outlet openings are located at the periphery of said chamber and at the outer edge of said vortex and issue pressurized liquid from said vortex in a direction determined by the rotational speed and direction of said vortex..]. .[.69. A spray device comprising:   a body member having a chamber region therein, an inlet opening for conducting pressurized liquid into said chamber region, and at least first and second outlet openings for issuing pressurized liquid from said chamber region to ambient environment;   fluid oscillator means in said chamber region for providing alternating oppositely-directed fluid vortices in response to conduction of said pressurized liquid into said chamber region; and   means responsive to said alternating fluid vortices for causing fluid to issue in cyclically swept patterns from each of said first and second   
     
     
        outlet openings..]. .[.70.  The method of oscillating a fluid jet comprising the steps of: issuing said jet into a chamber having a common inlet and outlet opening;   forming alternating oppositely-directed fluid vortices in said chamber from the fluid in said jet; and,   under the influence of said alternating vortices, alternately directing fluid to opposite sides of said jet and out of said chamber through said common inlet and outlet opening..]. .[.71. The method according to claim 70 wherein the step of forming comprises the steps of:   impinging the issued jet against a peripheral wall of said chamber; and   alternately directing fluid from the impinging jet in opposite tangential directions along said peripheral wall..]. .[.72. A spray-forming device comprising:   fluid oscillator means for receiving a flowing fluid and separating it into first and second fluid signals of varying amplitude and different phases;   a chamber including means for receiving said first and second fluid signals of varying amplitudes and different phases;   means for converting said fluid signals into a single body of vortically spinning fluid which fills said chamber and alternately spins in first and second directions in response to inflowing of said first and second signals to said chamber; and   outlet means for providing an output spray from said chamber to ambient environment, said spray being swept back and forth as said vortically spinning fluid spins in said first and second directions, respectively..]. .[.73. A spray-forming device comprising:   means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively;   said chamber having top and bottom walls and sidewalls, said output vortex being constrained to flow in a plane which is substantially parallel to at least one of said top and bottom walls;   said outlet means comprising an opening in said sidewalls which communicates between the chamber interior and ambient environment for issuing fluid from said chamber at a velocity which is the vectorial sum of a first vector directed tangentially to said output vortex at said outlet means and a second vector directed radially outward from said output vortex, said first vector being determined by the spin velocity of said vortex at said outlet means, said second vector being determined by   
     
     
        the static pressure at said outlet means..]. .[.74.  The device according to claim 73 wherein said opening is a slot having a length perpendicular to the plane of said output vortex which is greater than its width in the plane of said output vortex..]. .[.75. The device according to claim 73 wherein said opening is a slot having a length in the plane of said output vortex which is greater than its width perpendicular to the plane of said output vortex..]. .[.76. A spray-forming device comprising: means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid to said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively;   said chamber having top and bottom walls and sidewalls, said output vortex being constrained to flow in a plane which is substantially parallel to at least one of said top and bottom walls;   said outlet means comprising a plurality of openings in said sidewalls which communicate between the chamber interior and ambient environment for issuing fluid from said chamber at a velocity which is the vectorial sum of a first vector directed tangentially to said output vortex at said outlet means and a second vector directed radially outward from said output vortex, said first vector being determined by the spin velocity of said vortex at said outlet means, said second vector being determined by the static pressure at said outlet means..]. .[.77. A spray-forming device comprising:   means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and,   outlet means for providing ann output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively;   said chamber having top and bottom walls and sidewalls, said output vortex being constrained to flow in a plane which is substantially parallel to at least one of said top and bottom walls;   said outlet means comprising an opening in the periphery of said chamber which communicates between the chamber interior and ambient environment for issuing fluid from said chamber at a velocity which is the vectorial sum of a first vector directed tangentially to said output vortex at said outlet means and a second vector directed radially outward from said output vortex, said first vector being determined by the spin velocity of said vortex at said outlet means, said second vector being determined by the static pressure at said outlet means; and,   said opening comprising a notch defined through said top and bottom walls   
     
     
        and said sidewalls..]. .[.78.  A spray-forming device comprising: means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and,   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively;   said chamber having top and bottom walls and sidewalls, said output vortex being constrained to flow in a plane which is substantially parallel to at least one of said top and bottom walls;   said outlet means comprising an opening in the periphery of said chamber which communicates between the chamber interior and ambient environment for issuing fluid from said chamber at a velocity which is the vectorial sum of a first vector directed tangentially to said output vortex at said outlet means and a second vector directed radially outward from said output vortex, said first vector being determined by the spin velocity of said vortex at said outlet means, said second vector being determined by the static pressure at said outlet means; and   said outlet means issuing said output flow in the form of a cyclically swept sheet of fluid extending in width perpendicular to the plane of said output vortex..]. .[.79. A spray-forming device comprising:   means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a semi-spherical chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said   
     
     
        vortex spins in said first and second directions, respectively..]. .[.80. A spray-forming device comprising: means for providing first and second fluid repetitive flows of varying amplitudes and different phases from a single incoming flow of substantially constant amplitude;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from said first and second fluid flows into a single output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively..]. .[.81. A spray-forming device comprising:   means for providing first and second fluid repetitive flows of varying amplitudes and different phases;   a chamber having peripheral walls;   means for directing said first and second fluid flows in opposite generally tangential directions into said chamber along said peripheral walls;   means for converting the fluid from the inflowing fluid flows into an output vortex which fills said chamber and which alternately spins in first and second opposite directions in response to inflowing of said first and second fluid flows to said chamber; and   outlet means for providing an output flow from said chamber to ambient environment, which output flow is cyclically swept back and forth as said vortex spins in said first and second directions, respectively;   said chamber having top and bottom walls and sidewalls, said output vortex being constrained to flow in a plane which is substantially parallel to at least one of said top and bottom walls; and,   said outlet means comprising an elongated slot extending radially in one of   
     
     
        said top and bottom walls..]. .Iadd.82.  The oscillator according to claim 2 wherein said oscillation means further includes said flow directing means which directs said fluid from the jet sufficiently close to said jet at said common opening to provide mutual aspiration while avoiding momentum interchange between the jet and said fluid from the jet. .Iaddend. .Iadd.83. A fluid oscillator comprising: nozzle means for forming and issuing a jet of fluid in response to application thereto of fluid under pressure;   an oscillation chamber having a common inlet and outlet opening, said oscillation chamber being positioned to receive said jet of fluid from said nozzle means through said common opening, said oscillation chamber including: oscillation means for cyclically oscillating jet back and forth across said chamber in a direction substantially transverse to the direction of flow in said jet, said oscillation means including an impingement wall of said chamber devoid of discontinuities which project into said chamber and disposed in the path of said jet for forming two vortices, one on each side of said jet;     and means for alternating said vortices in strength and chamber position in   
     
     
        phase opposition. .Iaddend. .Iadd.84.  A fluid oscillator comprising: nozzle means for forming and issuing a jet of fluid in response thereto of fluid under pressure;   an oscillation chamber having a substantially central region and a common inlet and outlet opening, said oscillation chamber being positioned to receive said jet of fluid from said nozzle means through said common opening, said oscillation chamber including: oscillation means for cyclically deflecting said jet from side-to-side in said chamber in a direction substantially transverse to the direction of flow in said jet; and   flow directing means for directing fluid from the cyclically oscillated jet out of said chamber through said common inlet and outlet openings along both sides of said jet such that less flow egresses through said common inlet and outlet openings along the side toward which said jet is deflected than along the opposite side; and,   wherein said flow directing means directs said fluid from the jet close to said jet, but avoids momentum interchange between the jet and said fluid     
     
     
        from the jet..Iaddend. .Iadd.85.  The oscillator of claim 84 wherein said flow directing means directs said fluid from said jet sufficiently close to said jet at said common openings and at such an orientation to provide mutual aspiration while avoiding said momentum interchange between the jet and said fluid from the jet. .Iaddend.