US 3592042 A
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Description (OCR text may contain errors)
United States Patent Inventor Esteban Martinez 206 Brunswick Ave., Lambertville, NJ. 08530 Appl. No. 786,157
Filed Dec. 23, 1968 Patented July 13, 1971 FLUIDIC INDICATING DEVICE 11 Claims, 5 Drawing Figs.
US. Cl 73/23, 73/30, 73/53, 73/194, 137/81.5, 235/200 Int. CL .1 G0ln 33/00, F 15c 4/00 Field of Search 73/23, 30, 32, 53,194,205, 521, 524, 525; 137/81.5; 235/200, 201
References Cited UNlTED STATES PATENTS 3,186,422 6/1965 Boothe 137/81.5
3/1966 Bowles 137/81.5 3,366,130 1/1968 Reader.... l37/8l.5 3,343,341 9/1967 South .1 73/194 3,350,011 10/1967 Tooze... 235/201 3,435,837 4/1969 Sher 137/8l.5 3,444,876 5/1969 Sieracki 137/81.5
Primary Examiner-Richard C. Queisser Assistant Examiner-C. E. Snee, 111 Attorney-Sperry and Zoda ABSTRACT: An indicating device is provided with two nozzles positioned at an angle with respect to each other through which fluids are passed to form a common fluid stream and means contacted by the common fluid stream are utilized for indicating the direction of flow of the common fluid stream which in turn indicate the pressure ratio or other conditions of the fluids issuing from the nozzles.
IUVEUTOIL Esrsanu Umzrmsz nTT'otZuEYs The invention is in the field of fluidics and utilizes variations in the direction of flow of fluids received from angularly disposed nozzles for indicating a relation between the fluids issuing from the nozzles. Thus the direction of flow of a common fluid stream resulting from the contacting of fluids issuing from two angularly disposed nozzles will be a function of the momentum of the fluids at their point of contact. This momen- I turn may vary as a result of differences in the pressure and velocity of the fluids, the density thereof, or the angle at which the fluids meet in forming a common fluid stream. If the angle of inclination of the axes of the nozzles is fixed, the direction of flow of the resulting common fluid stream will vary in response to the pressure ratio and/or the density of the fluids. Accordingly, when the fluids employed have the same density the direction of flow of the common fluid stream will afford a direct indication of the pressure ratio of the fluids issuing from the nozzles. On the other hand, when the pressure ratio of the fluids is maintained constant the direction of flow of the common fluid stream will afford a direct indication of the density of the fluids issuing from the nozzles.
In accordance with the present invention means contacted by the common fluid stream are utilized for indicating the relation between the two fluids such as the relative pressure, density, temperature, humidity or other characteristics thereof, The means contacted by the common fluid stream in accordance with one embodiment of the invention are in the form of a vane or the like which is pivotally movable about an axis normal to the common stream at the intersection of the axes of the nozzles. The vane will then be movable by the common fluid stream into parallelism with the stream and a pointer operatively connected with the vane may be moved over a scale calibrated in terms of pressure ratio or the like as desired. In another embodiment of the invention sensing elements may be positioned to be contacted by the common fluid stream and be responsive thereto to control the operation of an electrical or optical instrument or the like to afford a desired indication of the relative condition of the fluids issuing through the two nozzles.
If desired, the means contacted by the common fluid stream may be utilized to vary or control relative position of the nozzles with respect to each other or to control the operation of equipment of any suitable type associated with mechanism embodying the present invention. Any such control means are hereinafter referred to as indicating means" for the reason that the nature and extent of the control effected will actually be an indication of the direction of flow of the common stream of fluid derived from the two nozzles.
In another embodiment of invention, the sensing elements are mounted on a rotatable platform driven by a motor. This motor, through the control of the sensing elements, will drive the platform so that the sensing elements are kept centered upon the stream. This feedback technique will cause the platform to rotate through the same angle as the common fluid stream. Therefore, this angle of rotation is itself an indication of the relative condition of the fluids issuing from the two nozzles.
- It will further be apparent that the common fluid stream utilized for actuating indicating means in accordance with the present invention may be derived from two or more nozzles or other sources if desired. The fluids employed in the practice of the invention may be either liquids or gases or combinations thereof.
THE DRAWINGS FIG. 1 is a diagrammatic illustration of typical equipment embodying the present invention;
FIG. 2 is a perspective view illustrating one type of indicating device embodying the present invention;
FIG. 3 illustrates an alternative embodiment of the present invention;
FIG. 4 is an enlarged view of a portion of the device illustrated in FIG. 3; and
FIG. 5 is a diagrammatic illustration ofa further alternative form of the present invention.
PREFERRED EMBODIMENTS OF THE INVENTION In that form of the invention illustrated diagrammatically in FIG. 1 the basic principle of operation of equipment utilizing the present invention is presented by the sources of fluid under pressure indicated at 2 and 4. The pressure source 2 supplies fluid under pressure to a duct 6 having a nozzle 8 through which the fluid issues axially as a stream flowing in a predetermined direction as shown by the dotted line 10. The fluid source 4 supplies fluid under pressure to a duct 12 having a nozzle 14 through which fluid issues axially as a stream flowing in the direction as indicated by the dotted line 16. The nozzles 8 and 14 are disposed at a predetermined angle with respect to each other such that the fluid from nozzle 8 will impinge upon the fluid from nozzle 14 and combine therewith the form a common fluid stream indicated at 18.
The nozzles 8 and 14 are each inclined at an angle 8 with respect to a center line 20 passing through the point of intersection of the axes of the nozzles. The direction of flow of the common fluid stream 18 with respect to the center line 20 will then depend upon the relative momentum of the individual streams of fluid l0 and 16. Thus, if the fluid in stream 10 is under higher pressure than the fluid in stream 16, the direction of flow of the common fluid stream 18 may be represented by the line 22 disposed at an angle A with respect to the center line 20. If all other conditions are held constant, the magnitude of the angle A will be related to the relative momentum of the fluid in streams l0 and 16. Therefore, when using identical fluids in streams l0 and 16, the angle A will indicate the pressure ratio of the fluid sources 2 and 4. This will be readily apparent from the laws of conservation of momentum under which 1* I, Aa1c tau tan B) wherein r EFefi1sTiE rhomentu rdratioif thatreams. If the losses in the ducts are kept small relative to the total energy of the flows, the stream momenta are proportional to the respective pressures. Then the momentum ratio is numerically equal to the pressure ratio and wherein M represents the momentum of the fluid stream 10 and M 2 represents the momentum ratio of fluid stream 16, while P and P 2 represent the pressures of the fluids in sources 2 and 4 respectively.
In the alternative, since R is proportional to the momentum of the fluid streams 10 and 16, if the pressure of the fluids in sources 2 and 4 are maintained constant, the angle A will represent the relative density of the fluids in streams 10 and 16. In this way the direction of flow of the common stream 18 may be used to indicate changes in composition, temperature, humidity or other properties of the fluids issuing from the nozzles 8 and 14.
In order to provide a directed reading of the pressure ratio or other properties of the fluids supplied from-sources 2 and 4 an instrument such as that illustrated in FIG. 2 may be employed. As there shown one fluid may issue from nozzle 30 in the direction indicated by the dotted line 32. The other fluid may issue from nozzle 34 in the direction of dotted line 36. These two streams intersect at the point 38 to form the common fluid stream 40. A fluid actuated element, such as the vane 42, is mounted for pivotal movement about an axis 44 passing vertically through the point 38 whereas the free end 46 of the vane is free to move into parallelism with the common fluid stream 40. A pointer or indicator 48 is operatively connected to the vane 42 by a shaft or the like 50 so as to be movable over a graduated scale 52.
The scale 52 may obviously be calibrated in any suitable manner to afford a direct reading of the relative pressure, velocity, temperature or composition of the two fluid streams as desired in any particular application of the invention.
The instrument illustrated by way of example in FIGS. 3 and 4 utilizes the same principle of operation. As shown in FIG. 3 the nozzles 62 and 64 are positioned at a predetermined angle with respect to each other so that fluid issuing therefrom in streams indicated by dotted lines 66 and 68 will intersect at the point 70. Sensing elements 72a, 72b, etc. are mounted on a support 74 in position to be contacted by the common fluid stream 76 resulting from the combining of the fluid streams 66 and 68. The support 74 upon which the sensing elements 72a,
72b, etc. are mounted is rotatable abouta vertical shaft 78 whose axes passes through the point of intersection 70 of the streams 66 and 68.
The sensing elements 72a, 72b, etc. may be of any suitable or preferred type such for example as thermistors which are placed predetermined distances apart as shown in FIG. 4. The common fluid stream 76 will then impinge upon those sensing elements in alignment therewith as represented by the elements 72c and 72d in FIG. 4. The latter sensing elements will thus be selectively actuated while the sensing elements 72b and 72c on opposite sides thereof will remain inactive.
The sensing elements which may be thermistors, apertures connected to fluid ducts or other suitable means, are operatively connected to suitable means such as a torque motor 80 connected to the shaft 78 of support 74 which will drive the support and sensing elements so that the common fluid stream will impinge at all times at a null point in the sensor assembly. This null point represents the position at which the net signal from the sensors becomes zero. The result of this closed-loop arrangement is to drive the support 74 continuously through the same angular motion as the common fluid stream. The support 74 illustrated is circular in shape and has gear teeth 82 engageable by a gear 84 carried by a shaft 86 of a potentiome ter 88 or other device to be actuated. Rotation of the support 74 by motor 80 in response to the control thereof effected by the sensing elements 72a, 72b, etc. will cause gear 84 to be rotated for actuating potentiometer 88. The potentiometer in tum may control the pumps or other regulating means for varying the pressure applied to the fluids issuing from the nozzles 62 and 64 or the potentiometer may otherwise serve to actuate equipment upon deviation of a characten'sticof the fluid jets from a predetermined norm or zero condition.
The servoing of the support 74 to the jet position allows the platform motion to provide substantial mechanical power which will drive transducers such as potentiometers accurately, in spite of the presence of friction and other forces.
An alternative construction embodying the present invention whereby such continuous response may be attained is illustrated in FIG. 5. As there shown the relative angular relation of the jets of fluid is varied to afford the desired indication or control of a system utilizing the invention. Thus a fixed nozzle 90 is mounted in predetermined relation with respect to a fixed scale or support 92 upon which sensing elements 94 may be mounted. A second nozzle 96 is mounted on a support 98 rotatable about a vertical axis 100 which passes through the point of intersection ,of the fluids issuing from the nozzles 90 and 96. Support 98 and nozzle 96 are movable by a motor 102 controlled by the reaction of the sensing elements 94 to the presence or absence of the common fluid stream 104 resulting from the interaction of the fluid jets issuing from the nozzles 90 and 96. The controlling action of the sensing elements is to drive the nozzle 96 and support 98 so as to always keep the common stream centered on the sensors, that is, in the equilibrium state, the resulting common fluid stream always has the same orientation, aligned with the sensors. The sensing elements may be thermistors, apertures connected to fluid lines or any other suitable means capable of reacting in response to the presence or absence of the common fluid stream upon contact thereby. The fixed support or scale 92 itself may be calibrated and utilized in combination with the movable support 98 to afford a visual indication of variations in the direction of the common fluid stream 104 and the characteristics of the jets of fluid issuing from the nozzles and 96 or the angular motion of the support 98 can be transmitted through gears or mechanical linkages to an output transducer. 4
In this arrangement, the laws of conservation of momentum produce a relationship between the pressure ratio and the angle B, described by the following equation:
B=arc sin (r sin B Where B is the angle through which the moving nozzle must be displaced to keep the common fluid stream centered on the sensors, and B o is the angle that the fixed nozzle 90 makes with the line running through the intersection of the axes of nozzles 90 and 96 and the midpoint of the sensors 94.
It will be apparent from the foregoing disclosure that the fluids employed in actuating the equipment may be derived from various sources and be of various types such as gases, liquids or mixtures thereof. The equipment controlled by the indicating devices of the present invention may be employed to actuate airfoils or other aerodynamic or fluid-dynamic surfaces or aircraft, boats, submarines and the like or to control fluid flow in pipelines, chemical apparatus and elsewhere as when itis desired to control the amount or rate of flow or utilization of gaseous or liquid fuels in combustion systems, engines, propulsion devices or the like. Accordingly, it should be understood that the particular embodiments of the invention disclosed in the drawings and described above are intended to be illustrative only and are not intended to limit the scope of the invention.
1. An indicating device comprising two sources of fluid under pressure, a nozzle associated with each of said fluid sources, said nozzles being directed at such an angle with respect to each other that the individual fluid streams issuing from said nozzles will combine to form a common fluid stream, sensing means positioned to be contacted by said common fluid stream to generate a signal relative to the angle of said common fluid stream from a predetermined norm, and actuating means responsive to operation of said sensing means for altering the characteristic of at least one of said individual fluid streams to return said angle of said common fluid stream to said predetermined norm.
2. An indicating device as defined in claim 1 wherein the direction of flow of said common fluid stream is variable in response to change in the momentum of the fluids issuing from said nozzles. I
3. An indicating device as definedin claim 1 wherein the fluid supplied to said nozzles is a gas and the direction of flow of said common fluid stream is variable in response to the relative pressure of the gas supplied to said nozzles.
4. An indicating device as defined in claim 1 wherein a plurality of sensing elements are located in position to be contacted by said common fluid stream, and an electrical device is connected to said sensing elements and controlled thereby.
5. An indicating device as defined in claim 1 wherein said nozzles are relatively movable to different angles with respect to each other.
6. An indicating device as deflned in claim 1 wherein the said actuating means indicates the pressure ratio of the fluids issuing from said nozzles.
7. An indicating device as defined in claim 1 wherein said actuating means is operable to compensate for relative variations of a characteristic of said individual streams from a predetermined norm.
8. An indicating device as defined in claim 1 wherein one of said nozzles is held in fixed position with respect to said sensing means and another of said nozzles is movable to different angular positions with respect to said fixed nozzle.
9. An indicating device as defined in claim I wherein said actuating means includes an electrical motor operable to move one of said nozzles to different angular positions with respect to another of said nozzles.
10. An indicating device as defined in claim 1 wherein there are two nozzles, one of which is held in a fixed position and the other of which is movable to various angular positions with respect to said fixed nozzle, said sensing means is positioned to be contacted by said common fluid stream when said movable nozzle is located in a predetermined position, and said actuating means is operable to restore said movable nozzle to said predetermined position upon displacement of said common fluid stream with respect to said sensing means.
11. A fluid pressure ratio indicating device comprising two sources of fluid pressure, a fixed nozzle supplied with fluid from one of said sources, a movable nozzle supplied with fluid from the other of said sources, said nozzles being positioned to produce fluid jets which intersect at a predetermined point to produce a common fluid stream, said movable nozzle being mounted on a support rotatable about an axis passing through said fixed point, sensing means positioned to be contacted by said common fluid stream when said movable nozzle is in a predetermined position and the pressure ratio of said fluid sources has a predetermined value, a motor for rotating said support to vary the relative angular positions of said fixed and movable nozzles, an electrical circuit including said motor and said sensing means, said sensing means being operable upon