US3421324A

US3421324A - Fluid flow control apparatus

Info

Publication number: US3421324A
Authority: US
Inventors: William R Bains
Original assignee: Philco Ford Corp
Current assignee: Space Systems Loral LLC
Priority date: 1966-05-03
Filing date: 1966-05-03
Publication date: 1969-01-14
Anticipated expiration: 1986-01-14

Description

Jan. 14, 1969 w, BAlNs 3,421,324

FLUID FLOW CONTROL APPARATUS Filed May 3, 1966 I N VEN TOR. W/Zl lAM R. BAH/VI AGfA/f United States Patent 3,421,324 FLUID FLOW CONTROL APPARATUS William R. Bains, Tustin, Califi, assignor to Phiico-Ford Corporation, a corporation of Delaware Filed May 3, 1966, Ser. No. 547,306 US. Cl. 60-231 Int. Cl. F021: 1/14; F152 ]/08; 1305b 7/08 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to apparatus for controlling fluid flow, and more particularly to improved apparatus for controlling the direction of flow of a stream of gas as it is discharged from the nozzle of a reaction motor. While of broader applicability, the invention has particular utility in the field of guidance systems for missiles or rockets.

One known system for propelling a missile by use of a gas stream issuing from a nozzle utilizes an auxiliary gas stream to control the direction of thrust of the propelling stream, whereby to steer the missile. In such apparatus, the issuing gas stream may be deflected from one position to the other by means of jets as gas released from a suitable auxiliary source and directed transversely of the main gas stream in the throat section of the reaction motor. The auxiliary source, in a typical prior arrangement, may comprise a container of gas under pressure. Gas is released from the container through electromechanical valves, as directed by the missiles guidance control system, thereby to deflect the path of the issuing gas stream and steer the missile.

It is a general objective of the present invention to provide improved auxiliary gas supply means of the abovementioned type for controlling deflection of the propelling stream, which means overcomes the need for maintaining a supply of control gas under pressure.

It is a further objective of the invention to provide improved auxiliary gas supply means that is both positive acting and rapid in achieving control of a main gas stream.

It is a still further objective of the invention to provide improved guidance control means which minimizes the use of moving parts and is highly reliable in operation.

To these general ends the invention contemplates, in a preferred embodiment thereof, the use of at least a pair of oppositely disposed control ports extending transversely of and into gas flow communication with the constricted neck portion of the missile nozzle, means defining at least a pair of chambers each in gas flow communication with a corresponding one of the control ports, and a plurality of combustible, gas generating charges disposed within each of the chambers. Means is provided for igniting the charges in accordance with a desired sequence required to guide the missile, ignition of a charge establishing instantaneous flow of a jet of gas through a corresponding one of the control ports. The jet is operable to deflect the stream of propellant gas flowing through the nozzle, and the vehicle is steered accordingly.

Advantageously, the invention overcomes the need for storing control gas under pressure, as well as the electromechanical valves usually associated with means for storlng gas.

The manner in which the foregoing as well as other objectives and advantages of the invention may best be achieved will be understood from a consideration of the following description, taken in light of the accompanying drawing in which:

FIGURE 1 is an elevational showing, partly in section, of apparatus embodying a preferred form of the invention, with some parts broken away and other parts shown diagrammatically;

FIGURE 2 is a sectional view taken along the line indicated by arrows 22 applied to FIGURE 1, and illustratingd additional constructional features of the invention; an

FIGURE 3 is a sectional view taken along the line indicated by arrows 3-3 applied to FIGURE 1.

With more particular reference to the drawing, and first to FIGURE 1, a missile or rocket 5 is constructed and arranged to be propelled by a stream of gas caused to flow through a convergent-divergent nozzle 10 having symmetry about a central axis common to both the nozzle and the missile. Preferably the nozzle 10 includes a generally conical flow divider 11, and divergent Walls 12 cooperably disposed with respect to flow divider 11 to form an annular outflow port, as is best seen in FIGURE 3. Flow divider 11 conveniently is supported by brackets 18 so dimensioned and spaced as not appreciably to obstruct the annular outflow port.

With reference also to FIGURE 2, first and second pairs of

control ports

13 and 14 interconnect pairs of

chambers

15 and 16, respectively, with opposite sides of a restrictive portion 17 of the nozzle 10. Chambers 15 and 16 include respective

tapered portions

15a and 16a leading up to

ports

13 and 14. These tapered portions serve to enhance flow of control gas through the control ports, as will be appreciated from further consideration of apparatus embodying the invention.

Supply of a main propellant gas stream to nozzle 10 is provided by known means, such as a propellant gas generator designated generally by the numeral 6, and connected to a nozzle inlet port 19 communicating with convergent nozzle portion 21 disposed upstream with respect to restrictive portion 17.

In particular accordance with the invention, arrays or groups of combustible, gas generating charges, such for example as squibs 22, are disposed in each of

chambers

15 and 16, preferably on side walls of the chambers opposite the

ports

13 and 14 communicating with narrow neck portion 17 of nozzle 10. Apparatus for igniting squibs 22 comprises individual control circuits 23 that extend through walls of

chambers

15 and 16 and are connected, through cable portions thereof, to guidance control means associated with the missile and designated generally by the numeral 24. A sufficient number of squibs 22 is provided so that control may take place for the duration of energization of the gas generator 6 with which the nozzle is associated.

Each of squibs 22 comprises a self-contained gas generator energizable by propellant of suitable composition, a number of which are known in the art. Ignition of the propellant also may be accomplished by suitable known bridge wire circuit means associated with control circuits 23. It of course will 'be understood that selection of the squib propellant will be such as to ensure compatibility of gases generated by a squib 22 and by the generator 6. Moreover, the construction and disposition of the squibs is such that firing of a squib in a chamber 15 will not adversely affect any other squib in that chamber.

Objectives and advantages of the invention will be more fully understood from a consideration of operation of the apparatus thus far described. Assuming first that energization of the gas generator 6 will cause a stream of propellant gas to issue from nozzle 10 in substantially equal quantities about flow divider 11, the missile will be steered on a substantially straight course. To effect a change of course, a signal is generated by control 24 igniting a squib 22 in chamber to create a gas pressure wave that moves with substantial force. The art provides a number of ways in which the control signal may be generated. However these will not be described herein since the invention is directed essentially to the novel squib and control port combination for controlling gas flow through a nozzle, as set forth in the appended claims. If detailed description of suitable means is desired, reference may be had, by Way of example, to the copending application of Louis G. Walters et al., bearing Ser. No. 371,715 and assigned to the assignee of the present invention.

The pressure wave created by the burning squib is transformed into a control jet of relatively hot gas as it moves from chamber 15, through tapered portion 15a, and through the port 13 communicating with the restrictive section 17 of nozzle 10. The control jet in moving from port 13 will impinge upon the issuing gas flow stream and deflect it, e.g. to the right, causing the stream to flow to the right of flow divider 11 as shown in FIGURE 1. The course of the missile is changed accordingly.

Once the force of the control jet has been dissipated, the main gas flow stream 25 will remain in the described deflected position due to the so-called Coanda effect, as is characteristic of apparatus of the type disclosed. In general, the Coanda effect is the tendency of a stream of fluid flowing close to a surface to be deflected toward the surface, and, under proper conditions, to flow tangentially to the surface and attach thereto.

As viewed in the two-dimensional showing of FIGURE 1, the flow of gas through nozzle 10 is stable in at least two states, and is therefore termed bistable. Since stability is achieved in at least two states, the issuing gas stream can be switched from the right side of the nozzle to the left side by igniting a squib to induce flow of a control jet through the control port that is nearer the displaced portion of the gas stream flowing through the restrictive nozzle portion 17. Since the issuing stream is maintained stable in its displaced position because of the Coanda effect, the control gas jet need only flow until deflection is achieved. Flow of a control jet from another direction, i.e. from one of the other control ports illustrated, must be initiated to switch the issuing stream to another position.

While operation of apparatus embodying the invention has been described in terms of a two-dimensional, bistable device, it will be understood that the illustrated apparatus is three-dimensional in construction, affording control in a plane perpendicular to the plane of FIGURE 1. This constructional feature is fully illustrated in FIGURE 2, where both such planes of control are illustrated.

It will be appreciated that steering is achieved in the disclosed nozzle 10 by alternate ignition of appropriately positioned squibs 22 under the control of means 24, and that a suflicient number of squibs will be provided in each chamber to achieve control for the duration of gas flow through the nozzle.

From the foregoing description it will be appreciated that the invention affords improved auxiliary gas supply means for controlling deflection of a gas stream issuing from a nozzle, which means overcomes the need for maintaining a supply of control gas under pressure. Moreover, the disclosed gas supply means is both positive acting and rapid in achieving control of the main gas stream. These characteristics adapt the apparatus of the invention to particular use in the guidance control means for a missile propelled by a reaction motor.

I claim:

1. Fluid flow control means comprising: nozzle means having a constricted throat section and a divergent exhaust portion through which a stream of gas may flow; at least a pair of spaced control ports positioned to direct jets of gas transversely of the stream of gas caused to flow through said nozzle means; means defining a pair of separate chambers, each chamber communicating with one of said ports; at least a pair of groups of individual, selectively energizable gas generating charges, the group of each said pair being disposed within a corresponding one of said chambers; and means for energizing said charges individually, in accordance with a desired sequence characterized by the energization of one charge of one group then one charge of the other group, the construction and arrangement being such that energization of a single charge is operable to create rapid flow of gas through a corresponding one of said control ports and to deflect the stream of gas flowing through said nozzle, such deflected stream thereafter flowing in adjacency to a surface of a divergent portion of said nozzle until another charge is fired and gas is caused to flow through the other control port.

2. Control means according to claim 1 and characterized in that ports of said pair are disposed opposite one another.

3. Fluid flow control means for guiding a vehicle propelled by a high velocity stream of gas flowing through nozzle means having a constricted neck portion and a wall portion divergent therefrom to form the exhaust for the flowing gas, said control means comprising: at least a pair of spaced control ports arranged to direct a jet of gas transversely of the recited stream of gas caused to flow through the constricted neck portion; a plurality of combustible, gas generating charges compris ing a pair of groups each disposed to effect the recited flow of gas through a corresponding control port; and means for igniting said charges in accordance with a vehicle guiding sequence characterized by ignition of charges of alternate groups, ignition of a single charge of one group being operable to establish the recited flow of a jet of gas through a corresponding one of said control ports and to deflect the stream of gas flowing through said nozzle to a position in which it is thereafter caused to flow adjacent a surface of the divergent Wall portion until a generating charge of another group is ignited to deflect the stream of gas for flow adjacent another surface of the divergent wall portion.

References Cited UNITED STATES PATENTS 2,956,401 10/1960 Kane 60-250 3,066,489 12/1962 Kirshner et al. 60-3947 X 3,143,853 8/1964 Sobey 60256 X 3,204,405 9/1965 Warren et al. 6023l 3,228,188 1/1966 Sargent et al. 60231 3,273,801 9/1966 Wilhite 60-231 X 3,279,185 10/1966 Lewis et al 60-231 3,285,262 11/1966 Ernst et al. 60231 X 3,300,978 1/1967 Pennington 60-231 CARLTON R. CROYLE, Primary Examiner.

US. Cl. X.R.