US3927694A

US3927694A - Fluidic computational device

Info

Publication number: US3927694A
Application number: US487507A
Authority: US
Inventors: Donald R Struttmann; William F Ryan
Original assignee: Garrett Corp
Current assignee: Garrett Corp
Priority date: 1974-07-11
Filing date: 1974-07-11
Publication date: 1975-12-23
Anticipated expiration: 1992-12-23

Abstract

The subject device consists of a fluidic amplifier having a reaction chamber, a nozzle for directing a fluid beam into the chamber, at least one output port across the chamber from the nozzle, a deflector projecting into and movable in the reaction chamber to vary the portion of the fluid beam received by the output port, and means for moving the deflector within the reaction chamber in the operation of the device. The deflector is designed (both in shape and movement) to vary the output in accordance with a predetermined formula. The means for moving the deflector may be responsive to a variety of forces such as the same fluid pressure supplied to the beam directing nozzle or some other suitable input signal.

Description

United States Patent Struttmann et a1.

FLUIDIC COMPUTATIONAL DEVICE Inventors: Donald R. Struttmann, Tempe;

William F. Ryan, Scottsdale, both of Ariz.

The Garrett Corporation, Los Angeles, Calif.

Filed: July 11, 1974 Appl. No.: 487,507

Assignee:

US. Cl 137/829; 137/83 Int. Cl. F15C 3/14; F15D 1/14 Field of Search 137/829, 830, 831, 832,

References Cited UNITED STATES PATENTS Longyear 137/83 3,638,671 2/1972 Harvey 137/831 Primary-ExaminerWi1liam R. Cline Attorney, Agent, or Firml-lerschel C. Omohundro;

James W. McFarland; Albert J. Miller [57] ABSTRACT The subject device consists of a fluidic amplifier having a reaction chamber, a nozzle for directing a fluid beam into the chamber, at least one output port across the chamber from the nozzle, a deflector projecting into and movable in the reaction chamber to vary the portion of the fluid beam received by the output port, and means for moving the deflector within the reaction chamber in the operation of the device. The deflector is designed (both in shape and movement) to vary the output in accordance with a predetermined formula. The means for moving the deflector may be responsive to a variety of forces such as the same fluid pressure supplied to the beam directing nozzle or some other suitable input signal.

8 Claims, 5 Drawing Figures U.S. Patent Dec. 23, 1975 Sheet 1 of2 3,927,694

US. Patent Dec. 23, 1975 Sheet 2 of2 3,927,694

BACKGROUND OF THE INVENTION The device of this invention relates to the class of apparatus exemplified by the following U.S. Pat. Nos. 3,638,671 to Harvey et al.; 3,509,775 to Evans; 3,470,914 to Smith; 3,276,473 to Lewis et al.; 3,276,463 to Bowles; 3,275,014 to Plasko; 3,258,024 to Bauer; 3,209,775 to Dexter et al.; 3,187,762 to Norwood; 3,102,389 to Pederson et al.; and possibly others issued in foreign countries. It differs from such apparatus in numerous details and functions, as well as results secured from the operation thereof.

SUMMARY This invention relates generally to the fluidics art wherein variable fluid flows, rather than mechanical elements, are relied upon for performing or controlling operating functions. In the present application, use is made of a combination of fluid flow, flow deflector shape and movement, and fluid pressure in the computation of output pressures.

An object of this invention is to provide a fluidic device which can be employed to generate an output signal constituting a predictable function of either a single or combination of input signals.

Another object of the invention is to provide a fluidic device which uses a fluidic amplifier modified by the addition of a fluid beam deflector embodying a particular design and moved in a predetermined manner by selected fluid or other forces.

A further object of the invention is to provide a fluidic computing device which utilizes the input supply pressure as one factor and the position of a fluid beam deflector in the reaction chamber of a fluidic amplifier as another factor in the computation.

A still further object of the invention is to provide a fluidic computing device of the character referred to in the preceding paragraphs having a fluid beam deflector of a predetermined design which when moved in a certain manner relative to the fluid beam will cause the device to produce output forces bearing definite relations to the inputforces supplied to the device.

Another object of the invention is to provide a fluidic computing device similar to the transducer shown in U.S. Pat. No. 3,638,671 to Harvey et al., but modified by utilizing a beam deflector having a different design and deflector moving means responsive to a variety of different forces.

A still further object of the invention is to modify the deflector of U.S. Pat. No. 3,638,671 referred to above by imparting a lateral bend or longitudinal curvature thereto and moving the deflector axially relative to itself in the path of the fluid beam produced by the inlet nozzle, the bendor curvature being calculated by a predetermined formula to cause the output of the device to be proportional to the product of forces constituting the input to the device.

Other objects and advantages will be made apparent by the following description of various embodiments of the invention selected for illustration in the accompanying drawings.

IN THE DRAWINGS FIG. 1 is a schematic in perspective 'of a portion of a fluidic system in which a computational deviEE lii bodying the invention is incorporated;

FIG. 2 is a vertical transverse sectional view taken through the computational device on the plane indicated by the line 11-" of FIG. 1;

FIG. 3 is a sectional view similar to FIG. 2 taken through a modified form of computational device;

FIG. 4 is a schematic in perspective of a further modified form of computational device; and

FIG. 5 is a view similar to FIG. 2 showing a modified form.

DESCRIPTION Referring more particularly to the drawings, and especially FIGS. 1 and 2, it will be observed that the fluidic system pictured has a source 10 of fluid pressure, an amplifier, generally indicated by the numeral 11, the latter having a body 12 forming a reaction chamber 13. The body is further provided with an inlet 14 communicating with the source 10 by a passagelS. In addition, the body has output ports, in this instance two, identified by numerals l6 and 17, which are disposed at one side of the chamber 13 and have a relatively sharp splitter wall 18 between them. At the opposite side of the chamber 13 from the output ports, the body is formed with a nozzle 20 connecting with the inlet port and serving, when fluid under pressure is supplied thereto, to direct a fluid beam toward the output ports. The latter, when arranged as shown and nothing is disposed to interfere, will receive equal amounts of the fluid beam directed thereto by the nozzle 20.

Passages

21 and 22 leading from the

output ports

16 and 17, respectively, will at this time contain equal pressures.

From the objects it will be understood that the purpose of the device is to produce pressures in

passages

21 and 22 bearing a predetermined relation to some other values such as force, position, temperature, etc. To accomplish this purpose, the amplifier is equipped with a deflector element 23 which may be moved into or within the fluid beam issuing from the nozzle 20 to vary the proportions of the beam received by the output ports. Thus far, the device shown and described is similar to the transducer forming the subject matter of U.S. Pat. No. 3,638,671 referred to above. In contrast to the patent,'however, the deflector element 23 herein is contoured and moved differently from that in the patent.

From FIGS. 1 and 2 it will be noted that the deflector element 23 has a circular cross-section, but is curved longitudinally in accordance with a predetermined formula. The element 23 is supported preferably for movement axially relative to itself in the reaction chamber 13. Due to the configuration of the deflector and the manner of movement, the proportion of the fluid beam received by the output ports may be varied as desired.

To support the deflector, the form of device shown in FIGS. 1 and 2 has an actuator 24 mounted over the body 12 with the deflector projecting downwardly into the reaction chamber 13. Actuator 24 comprises a casing 25 forming a chamber 26 divided by a diaphragm 27 into pressure and

spring regions

28 and 30, respectively. The deflector is fixed to the center of the diaphragm at one end, the other end extending into the reaction chamber of the amplifier 11. A spring 31 surrounds the deflector and has one end in engagement with the diaphragm and the other bearing against the casing wall; the force of the spring urging the diaphragm ttiwafti the pressure receiving section 28 of the actuator chamber 26. The diaphragm is moved in opposition to the spring 31 by fluid pressure introduced into the pressure receiving region 28 of the actuator through an inlet 32. Movement of the diaphragm in this manner tends to cause the deflector to traverse the path of the beam issuing from the nozzle and vary the part of the beam entering the output ports. The degree of beam deflection will obviously depend in part on the shape and size of the deflector and in part on the extent of movement. It will be seen from the foregoing that the spring force and rate, as well as the pressures of the fluids applied to the diaphragm and the beam forming nozzle, will affect the pressures issuing from the

output ports

16 and 17. All of these values will be considered in the design of the unit.

For purposes of this discussion, the supply pressure entering the inlet 14 is designated P, and the pressures at the

output ports

16 and 17 are identified as P and P respectively. The device can be used to generate an output signal which is a predictable function of either one or two input signals. In its general form the device accepts two independent inputs (one of which may be constant) and produces an output that is proportional to the product of the two inputs, i.e., Output (input No. l) X (input No. 2). In the use of the device, one input is the supply pressure P applied to the fluidic amplifier. The other input is the position X of the deflector. As suggested, it is possible to shape the deflector in such a manner that the output can be made a predetermined function (either linear or nonlinear) of the input which moves the deflector element.

As illustrated in FIGS. 1 and 2, the deflector is in the form of a round pin projecting into the path of the fluid beam issuing from the nozzle. The output pressure differential (P -P may be varied by moving the deflector, i.e., changing the position X, to vary the relative blockage of the output ports. It should be obvious that the output may, in part, be predetermined by the proper shaping of the deflector.

Another factor in predetermining the output is the selection of the supply pressure P, and the pressure introduced into the inlet 32 of the deflector actuator 24. This introduction of pressure may be suitably controlled as by a temperature responsive valve 33 or other means.

Due to proportionality of the output to both deflector position and supply pressure, the device inherently performs the function of multiplying the two input variables to produce the general relation:

P, P KP, Xf(x) where P, P output pressure differential;

K a constant depending on element and deflector design;

flx) a function that can be controlled by the shape of the deflector;

P, power jet supply pressure.

The computational capabilities of the device include:

1. transduction of a mechanical motion into a proportional pressure signal;

2. multiplication of two independent variables;

3. multiplication of a single variable by a constant;

4. generation of an output proportional to functions of an input variable (x) including (but not limited a. trigonometric functions (sine, cosine, tangent,

etc.) of (x);

b. logarithmic functions of (x);

c. powers of (x), i.e., x x etc.; d. nonanalytic functions of (x).

In certain instances, such as when the device is to be used as a position transducer, the deflector 34 is shaped (see FIG. 3) to yield a linear function of (x) and the supply pressure to the fluidic portion of the device is held constant. In this form of apparatus, the deflector has a circular cross-section and is inclined laterally at a selected fixed angle. When the deflector is moved in the fluid beam, it will traverse it in a uniform manner and the output will then be linearly proportional to P (the signal applied to the deflector actuator) only.

Some computations involving a large percentage of natural phenomena require extraction of the square root. By proper shaping of the deflector, the output of the device can be made equal to the square root of the deflector displacement along its axis. In the case where the input is displacement, the deflector can be driven directly. If the input were differential pressure, it would be converted to displacement by suitable combinations of diaphragms and/or pistons and springs.

By making the power jet supply pressure and the position of a linearized deflector proportional to the variable (x), the square of (x) can be generated.

Two independent variables can be multiplied by making the device as shown in FIG. 4, where one variable is converted to deflector displacement and the other variable is converted to fluidic element supply pressure. In FIG. 4 the fluidic amplifier is similar to that in the other forms but the deflector is a straight pin 35 mounted on a lever 36 pivoted, as at 37, to move the deflector laterally across the path of the fluid beam. Movement is imparted to the lever by a bellows 38 connected at its free end to the lever by a connecting rod 39. Input pressure P is supplied to the bellows while a different input pressure P,, is supplied to the inlet of the amplifier. The differential output pressure AP from the device will be equal to K(P, X P,,), K

being a constant depending on the element and deflector design.

It should be obvious that since the operation of the device depends, in part, upon the position of the deflector relative to the fluid beam, the manner in which the deflector is moved is not critical. In FIGS. 1 to 4, inclusive, the forms of the invention shown utilize fluid pressure to effect deflector movement. This element could equally well be moved, as shown in FIG. 5, mechanically, by a cam 40 or other motion transmitting member, engaging the deflector shaft and imparting movement directly thereto. In this form, one of the variable input factors will be that which causes the rotary movement of the cam.

We claim:

1. A fluidic computational device comprising:

a. a fluidic amplifier having a body forming a reaction chamber with ajet nozzle at one side communicating with an inlet for fluid under predetermined pressure and at least one output port leading from the reaction chamber at the side opposite said jet nozzle, fluid under said predetermined pressure supplied to said inlet being formed by said nozzle into a fluid beam directed toward said output port;

b. a deflector element projecting into the reaction chamber between said jet nozzle and said output port, said element being of elongated form with a circular cross section and nonlinearly shaped in a longitudinal, nonaxial direction to traverse the path of the fluid beam at a predetermined nonlinear rate relative to linear movement of the deflector element in an axial direction in said reaction chamber; and

c, means for linearly moving said deflector element in said axial direction in said reaction chamber, said means having an actuator responsive to a variable input pressure, the portion of the path of the fluid beam traversed by said deflector element and the resulting pressure in said output port bearing a predetermined nonlinear relation to said linear movement of the deflector element in said axial direction.

2. The fluidic computational device of claim 1 in which the deflectormoving means imparts axial reciprocatory movement to said deflector.

3. The fluidic computational device of claim 1 in which the deflector is shaped to progressively traverse the path of the fluid beam.

4. The fluidic computational device of claim 1 in which the deflector is shaped to cause the output pressure to be a linear function of the fluid pressure to which the deflector moving means is responsive.

5. The fluidic computational device of claim 1 in which the deflector moving means and amplifier nozzle inlet are supplied with the same fluid pressure.

6. The fluidic computational device of claim 1 in which two output ports with a beam splitter therebetween are provided.

7. The fluidic computational device of claim 1, wherein said deflector element is arranged to traverse the path of the fluid beam at said predetermined nonlinear rate in said longitudinal direction.

8. A fluidic computational device comprising:

a fluidic amplifier having a body forming a reaction chamber with ajet nozzle at one side communicating with an inlet for fluid under predetermined pressure and at least one output port leading from the reaction chamber at the side opposite said jet nozzle, fluid under said predetermined pressure supplied to said inlet being formed by said nozzle into a fluid beam directed toward said output port;

b. a deflector element projecting into the reaction chamber between said jet nozzle and said output port; and

0. means for linearly moving said deflector element in an axial direction in said reaction chamber, said deflector element being of axially elongated form with a circular cross section and being nonlinearly curved in a longitudinal nonaxial direction to traverse the path of the fluid beam and alter the pressure in said output port at a predetermined nonlinear rate in relation to said linear movement of the deflector element in said axial direction.

Claims

1. A fluidic computational device comprising: a. a fluidic amplifier having a body forming a reaction chamber with a jet nozzle at one side communicating with an inlet for fluid under predetermined pressure and at least one output port leading from the reaction chamber at the side opposite said jet nozzle, fluid under said predetermined pressure supplied to said inlet being formed by said nozzle into a fluid beam directed toward said output port; b. a deflector element projecting into the reaction chamber between said jet nozzle and said output port, said element being of elongated form with a circular cross section and nonlinearly shaped in a longitudinal, nonaxial direction to traverse the path of the fluid beam at a predetermined nonlinear rate relative to linear movement of the deflector element in an axial direction in said reaction chamber; and c. means for linearly moving said deflector element in said axial direction in said reaction chamber, said means having an actuator responsive to a variable input pressure, the portion of the path of the fluid beam traversed by said deflector element and the resulting pressure in said output port bearing a predetermined nonlinear relation to said linear movement of the deflector element in said axial direction.

2. The fluidic computational device of claim 1 in which the deflector moving means imparts axial reciprocatory movement to said deflector.

8. A fluidic computational device comprising: a fluidic amplifier having a body forming a reaction chamber with a jet nozzle at one side communicating with an inlet for fluid under predetermined pressure and at least one output port leading from the reaction chamber at the side opposite said jet nozzle, fluid under said predetermined pressure supplied to said inlet being formed by said nozzle into a fluid beam directed toward said output port; b. a deflector element projecting into the reaction chamber between said jet nozzle and said output port; and c. means for linearly moving said deflector element in an axial direction in said reaction chamber, said deflector element being of axially elongated form with a circular cross section and being nonlinearly curved in a longitudinal nonaxial direction to traverse the path of the fluid beam and alter the pressure in said output port at a predetermined nonlinear rate in relation to said linear movement of the deflector element in said axial direction.