US3302888A

US3302888A - Secondary-injection thrust vector control valve

Info

Publication number: US3302888A
Authority: US
Inventors: Allen B Holmes; John E Foxwell
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-05-25
Filing date: 1965-05-25
Publication date: 1967-02-07
Anticipated expiration: 1984-02-07

Description

Feb. 7, 1957 A. B. HOLMES ETAL 3,302,888

SECONDARY-INJECTION THRUST VECTOR CONTROL VALVE Filed May 25, 1965 INVENTOES,

7 ALLEN 5. HOLMES Jam/5. fioxwsu.

A 1 TOIYNE 7s United States Patent O Filed May 25, 1965, Ser. No. 459,981 2 Claims. (Cl. 239-26513) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to us of any royalty thereon.

This invention relates generally to supersonic, threedimensional fluid amplifiers, and more particularly to a fluid amplifier thrust vector control system for reaction jet engines.

One way to steer or control jet-propelled vehicles is thrust vector control. Basically, thrust vector control means control by deflection of the main propulsion jet. One way to do this is by secondary fluid injection; that is, an auxiliary fluid is injected into the main reaction jet nozzle, causing the main propulsion jet to deflect. A few examples of systems of this type may be found in the patents to Wetherbee, Patent No. 2,943,821; Walker, Patent No. 2,916,873; and Kadosch et al., Patent No. 2,812,636.

To get good control of reaction jet engines by means of secondary injection thrust vectoring, it is necessary to have available at each secondary injection nozzle about six percent of the main reaction trust jet. This amount of fluid is necessary to give quick response under full control conditions. Very often, in prior systems, the secondary injection fluid is an auxiliary fluid, carried separately, specially for control purposes. While in many applications this system is satisfactory, there is a sacrifice in overall efliciency because of the increased nonthrust-producing weight. An inherently more attractive system is to bleed the reaction products from the combustion chamber of the engine for use as secondary injection fluid. With this system, no auxiliary control fluid is needed, and overall efliciency and performance are enhanced. Bleed system proposals, however, have been around for a number of years, and yet, as far as the applicants are aware, no really satisfactory system is available. The problem lies in controlling the hot-gas, high-velocity, reaction prod ucts from the combustion chamber with the precision required for the thrust vector control.

In another co-pending application Serial No. 352,695, filed March 17, 1964, in which the applicants of the present invention are co-inventors with another and which is assigned to the assignee of the present application, there is disclosed a novel one-leg fluid amplifier control system. This system includes a supersonic jet-forming nozzle with its flow axis unobstructed so that the full reaction thrust of the nodzle may be developed. Displaced from one side of the main jet flow axis is a splitter and fiuid catcher channel. On the same side of jet axis is means to proportionately control the amount of entrainment of the jet formed by the supersonic nozzle. The proportionate control means has no moving parts in the hot-gas stream, but,- by controlling the amount of entrainment, it is effective to control the amount of fluid which impinges on the splitter and is directed into the catcher channel.

3,3i2,888 Patented Feb. 7, 1967 The particular proportionate control means is an atmospheric bleed valve. While this sytsem has functioned Well it has become evident that the usefulness of the sys tem falls oif with increasing altitude because of the lack of atmospheric air to provide a pressure gradient for switching.

It is therefore an object of this invention to provide a three-dimensional, supersonic proportional control fluid amplifier capable of controlling react-ion jet engines at high altitudes.

It is another object of the instant invention to provide a combustion chamber bleed, secondary injection, thrust vector control system for reaction jet engines which has no moving parts in the hot-gas stream and which is capable of operation both within and without the earths atmosphere. 7

It is a further object of this invention to provide a reaction chamber bleed, t-hrust vector control system which provides continuous proportionate control of the injection gas from full-on t'o full-off independent of altitude.

According to the present invention, these and other objects are accomplished by providing within the control system disclosed in the aforementioned application Serial No. 352,695 a pressure supplied cont-r01 nozzle placed so as to be diametrically opposed to the atmospheric bleed control port.

The specific nature of the invention, as well as other objects, aspects, uses and advantages thereof, will clearly appear from the following description and from the accompanying drawing, in which:

FIG. 1 is a perspective view of a one-leg, three-dimensional, supersonic fluid amplifier according to this invention;

FIG. 2 is a sectional schematic view of a one-leg, fluid amplifier according to this invention; and

FIG. 3 is a sectional schematic view of a thrust vector control system according to this. invention.

Referring now to the drawing in which like reference numerals designate similar or identical parts throughout, and more particularly to FIGS. 1 and 2, which show a one-leg, fluid amplifier which includes a convergingdiverging nozzle 12 and having a mounting flange 13 for attachment to a reaction chamber bleed port. The nozzle 12 has an orifice 15 with a principal jet thrust axis along the line 14. Located downstream from the nozzle orifice 15 is a splitter 18. The splitter 18 is located far enough to one side of the principal thrust axis 14 that virtually none of the jet stream issuing from nozzle 12 impinges upon the splitter in the absence of a control signal. On the same side of the principal thrust axis 14 as the splitter 18 is a fixed system 19 for proportionately controlling the amount of fluid jet stream directed into a conduit or channel 17. The fixed system 19 includes a channel 21 extending out from the diverging portion of the nozzle 12. As is shown, there is a control port 24 in the channel 21 closely adjacent the nozzle 12. Separated from the port 24 by a channel 25 is an entrainment control valve 23 which is in communication with atmosphere via the chamber surrounding it (as seen in FIG. 3). By limiting the amount of air flow through the valve 23, the jet stream will be deflected from the axis 14 toward the splitter 18; that is, as the valve 23 is gradually closed, limiting the amount of air supplied to port 24, the jet stream issuing from nozzle 12 is proportionately directed toward the "3 J splitter 18. With the valve 23 closed, substantially the entirejet stream is directed into channel 17.

The mechanism of operation of the fluid amplifier shown in FIGS. 1 and 2 is due to the Coanda eflect. In his Patent No. 2,052,869, Henri Coanda points out that when a fluid jet issues through a suitable nozzle into another fluid, such as air, it will carry along with it a portion of the surrounding fluid if its velocity is sufficient. In other words, the jet will create a suction effect on the surrounding fluid at the point of discharge from the nozzle. It, at the outlet of the nozzle, there is set up an unbalancing effect on the flow of surrounding air induced by the jet, the jet will move towards the side on which the flow of the surrounding fluid has been made more difficult.

The fluid amplifier described in FIGS. 1 and 2 applies the principles of the Coanda effect in three dimensions. Channel 21 is rigidly attached to nozzle 12, and the side walls of channel 21 are of suflicient height to prevent entrainment in the lateral direction. With the valve 23 closed, or partially closed, there will be a greater pressure on the jet issuing from the nozzle 12 on the side away from splitter 18 due to the lower pressure at port 24 caused by the restricted entrainment. This unbalance in pressure deflects the jet forward splitter 18. The jet issuing from nozzle 12 will have a supersonic velocity when the pressure ratio across nozzle 12 is greater than 2. This pressure ratio will, of course, be present when the fluid is supplied from the combustion chamber of a reaction jet engine. A supersonic jet will induce a large amount of entrainment of the surrounding air, and this high entrainment characteristic gives a high degree of control to valve 23.

The fluid amplifier thus far disclosed is that disclosed in the aforementioned application Serial No. 352,695. This invention provides an additional fluid control nozzle 27 located diametrically opposite port 24. The nozzle 27 is supplied with a fluid under pressure from an auxiliary fluid source (not shown) by way of a conduit or channel 28. Fluid issuing from nozzle 27 interacts with the jet issuing from nozzle 12 causing the jet to deflect toward channel 21. Assuming the fluid issuing from nozzle 27 is under a constant pressure, the angle of deflection of the jet is dependent on the quantity or mass of the fluid issuing from nozzle 27. The quantity of fluid supplied to nozzle 27 by way of channel 28 may be controlled by any well known valving mechanism.

The addition of nozzle 27 eliminates the inherent altitude limitations of the control system disclosed in application Serial No. 352,695 and allows the system to function etficiently at very high altitudes. Thus, as the effectiveness of the valve 23 decreases with increasing altitude, deflection of the jet issuing from nozzle 12 may be gradually and increasingly produced by fluid caused to issue from control nozzle 27. Since only a small amount of fluid issuing from control nozzle 27 is required to deflect the jet issuing from nozzle 12, and since control of the jet issuing from nozzle 12 by means of fluid issuing from nozzle 27 is required only in high altitude operation, the source of auxiliary fluid under pressure is minimal.

The offset of the splitter 18 from the thrust axis 14 and its distance from the nozzle 12 are primarily determined by the characteristics of the jet issuing from nozzle 12, which in turn is determined by the nozzle design and the supply fluid characteristics. That is, the oflset should be suflicient that no fluid impinges on the splitter 18 when valve 23 is opened, yet the splitter 18 should be close enough to nozzle 12 that the jet stream is still moving at supersonic volocity when it enters the channel 17.

FIGURE 3 shows the control system of this invention to control a reaction jet engine. The reaction jet engine has a combustion chamber 31, with a converging-diverging power nozzle 32. The principal thrust axis of the engine is along the axis 33. To control the jet engine and the vehicle which it powers there are thrust

vector control systems

35 and 36. While only two systems are shown, it will be obvious to those skilled in the art that an actual system would ordinarily employ four units-one unit for each directionin order to achieve three-dimensional control. The broad function of the

control systems

35 and 36, which are identical, is to bleed a proportion of the reaction products from the combustion chamber 31 through ports 37 and inject a controlled amount on demand into main reaction nozzle 32 through thrust vectoring nozzles 38. In order to achieve good control it is usually necessary that about six percent of the main rocket thrust in pounds be available at each control nozzle. This requires that each control system such as 35 or 36 be capable of channeling a significant amount of fluid to the secondary control nozzles under full control conditions.

In order that the thrust

vector control system

35 and 36 be efficient, the auxiliary control nozzles 12 have their principal thrust axis substantially parallel to the main rocket thrust axis 33. In FIGURE 3, the axes 14 are actually inclined slightly with respect to the axis 33 in order that the control system thrust axis 14 pass through the center of gravity of the engine so that the control system does not create a turning moment on the engine. This is not absolutely necessary, since as is apparent, if the

units

35 and 36 are balanced even though the thrust axis 14 is parallel to axis 33, the turning moments will cancel.

With no control, substantially the full forward thrust of the engine is developed in the main jet nozzle 32 and the auxiliary control nozzles 12. When it is desired to deflect the principal thrust jet issuing from nozzle 32, one of the valves 23, for example of system 36, is closed an amount proportional to the distance the main jet is to be directed away from its axis 33. With the valve 23 partially closed, part of the jet stream from nozzle 12 is directed to the channel 17 and issues from thrust control nozzle 38, while the remainder of the jet stream is directed substantially along the main axis 33 providing propulsion power. At higher altitudes, fluid from the control nozzle 27 is caused to issue against the jet issuing from nozzle 12. The amount of the fluid issuing from control nozzle 27 is made to be proportional to the distance the main jet is to be deflected away from its axis 33, as before.

As will be apparent to those skilled in the art, the applicants have provided an efficient thrust vector control system which can provide continuous proportionate control of. the main thrust jet either within or without the earths atmosphere. This control system does not require moving parts in any hot-gas path. In terms of the present state of the art, this in combination with the high thrust recovery of the system in the absence of a control signal makes this system a very practical and operative one. The gain of the applicants fluid amplifier system can most significantly be measured in terms of flow; that is, the ratio of control flow and change in pressure through valve 23, or fluid flow through control port 27, to the change of fluid jet flow in pressure through conduit 17. Gains on the order of 10,000 have been realized with systems of the type described.

It will be apparent that the embodiment shown is only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention as defined in the appended claims.

We claim as our invention:

1. A secondary injection, thrust vector system for use with a reaction jet engine which has a combustion chamber and a main reaction jet nozzle with a thrust axis, comprising:

(a) a bleed connected to said combustion chamber,

(b) an auxiliary control nozzle connected to said bleed and having an unobstructed principal thrust axis along which an auxiliary control jet issues,

(c) a semi-cylindrical section connected to said control nozzle and extending therefrom to form an open channel and being located on one side of said principal thrust axis,

(d) a splitter located Wholly on the same side of said principal thrust axis as said open channel,

(e) first control means for controlling the direction of said auxiliary control jet including a passage connected to atmosphere and having a port leading into said open channel,

(f) a fluid conduit connected to said main reaction jet nozzle, said splitter adapted to direct a portion of said auxiliary jet impinging thereon to said conduit, and

(g) auxiliary control means for controlling the direction of said auxiliary jet including a pressure fluid supplied nozzle opposite the principal axis of said auxiliary nozzle from said first control means and effective to progressively control said auxiliary jet when said first control means is ineffective because of high altitudes.

2. A device according to claim 1 wherein valve means are located in said first control means passage to progressively control the movement of said auxiliary jet.

References Cited by the Examiner OTHER REFERENCES Fluid Oscillator, by A. E. Mitchell, I.B.M. Technical Disclosure Bulletin, vol. 5, No. 6, November 1962, page 25.

Fluid Control Device by Stanley W. Angrist, Scientific American, December 1964, pages 82, 83 and 86.

CARLTON R. CROYLE, Primary Examiner.

SAMUEL FEINBERG, Examiner.

Claims

1. A SECONDARY INJECTION, THRUST VECTOR SYSTEM FOR USE WITH A REACTION JET ENGINE WHICH HAS A COMBUSTION CHAMBER AND A MAIN REACTION JET NOZZLE WITH A THRUST AXIS, COMPRISING: (A) A BLEED CONNECTED TO SAID COMBUSTION CHAMBER, (B) AN AUXILIARY CONTROL NOZZLE CONNECTED TO SAID BLEED AND HAVING AN UNOBSTRUCTED PRINCIPAL THRUST AXIS ALONG WHICH AN AUXILIARY CONTROL JET ISSUES, (C) A SEMI-CYLINDRICAL SECTION CONNECTED TO SAID CONTROL NOZZLE AND EXTENDING THEREFROM TO FORM AN OPEN CHANNEL AND BEING LOCATED ON ONE SIDE OF SAID PRINCIPAL THRUST AXIS, (D) A SPLITTER LOCATED WHOLLY ON THE SAME SIDE OF SAID PRINCIPAL THRUST AXIS AS SAID OPEN CHANNEL, (E) FIRST CONTROL MEANS FOR CONTROLLING THE DIRECTION OF SAID AUXILIARY CONTROL JET INCLUDING A PASSAGE CON-