US3387787A

US3387787A - Arrangement for controlling the deflection of a jet stream emitted by a nozzle

Info

Publication number: US3387787A
Application number: US567619A
Authority: US
Inventors: Colonbani Don Pierre Loui Jean; Ernst Adolphe Otton Gontier
Original assignee: SNECMA SAS
Current assignee: Safran Aircraft Engines SAS
Priority date: 1965-08-02
Filing date: 1966-07-25
Publication date: 1968-06-11
Anticipated expiration: 1985-06-11
Also published as: DE1481656A1; GB1142401A; FR1453404A

Description

June 1968 D. P. L. J. COLONBANI ETAL 3,387,787

ARRANGEMENT FOR CONTROLLING THE DEFLECTION OF A JET STREAM EMITTED BY A NOZZLE 2 Sheets-Sheet 2 Filed July 25, 1966 United States Patent 6,953 6 Claims. (Cl. 239-26517) The invention relates to nozzles, more especially for jet engines, in particular to a method of and arrangement for effecting deflection of the jet stream emitted by a nozzle.

I Several deflection methods are known, among themthe transverse injection of an auxiliary liquid jet into the jet stream. This injection into a noule provides a deflection of the jet stream which is proportional to the injection pressure and to the auxiliary fluid flow rate (in a certain area of employment).

If it is desired to obtain a linear variation in the deflection, between zero and maximum deflection, as a function of an input signal, the injection pressure may, for instance, be kept constant and the flow rate may be made to vary linearly. Complications in putting this into effect are then met with, however. A flow rate valve system upstream of the injection simultaneously creates a variation in injection pressure.

An object of the present invention is therefore to provide a nozzle providing jet stream deflection by the transverse injection of liquid in an improved manner. The method herein described is based on the known method of injection via a manifold and using an upstream valve system in a cool location. A different solution for the control of the auxiliary injection is, however, adopted.

The essential characteristic of this invention rests in the fact that injection is effected through manifolds which include holes of the same general dimensions but the numbers of which are arranged according to the successive powers of two, each manifold being controlled by an on-off type valve. The known valve system for continuous regulation of the auxiliary injection is thereby replaced by a combination of discrete modes, which makes it possible to render the deflection control linear by appropriate selection of the number of injection holes which are open.

The following description with reference to the accompanying drawings, and given by way of non-limitative example, will bring out the various features of the invention and the art of putting them into effect, any arrangement arising from the text or from the drawings naturally falling within the scope of the present invention, as defined by the appended claims.

In the accompanying drawings,

FIGURES 1a and lb show by way of example one arrangement of holes for assemblies of three and four manifolds respectively;

FIGURE 2 is a diagram on which is illustrated the stepped variations in flow rate obtained by a combination of three and of four manifolds;

FIGURE 3 shows a view in axial section of a slidevalve distribution means which may replace an assembly of three on-otf type valves;

FIGURE 4 shows how the different positions of the distributor make possible a numerical combination of fractional flow rates in the form of steps, here from 0 to 7;

FIGURE illustrates the straight line relative to distribution to which an approximation may be effected if "ice compensation be made for the loss of pressure associated with the intermediate positions of the distributor.

The transverse injection of liquid into a nozzle brings about a deflection of the jet stream at the nozzle exit. This deflection is proportional to the pressure of the injection liquid and to the flow rate of the said liquid. Hence, if it is desired to bring about a linear variation in the deflection of the nozzle jet stream between zero and the maximum angular value, one of the two possible methods consists in maintaining the pressure of the injection liquid constant and in causing its flow rate to vary linearly.

Hence, the proposed solution consists in deflecting the jet stream leaving a nozzle, for intsance a rocket-motor nozzle 20, by the action of an injection of auxiliary liquid originating in a tank 24. This injection is made up of a set of elementary jets injected through manifolds, each manifold being controlled by an on-0E type valve.

These injection manifolds include holes having the same section, but in numbers according to the successive powers of two. Thus, for example, considering the case of an arrangement with three manifolds having 1, 2 and 4 holes respectively (or, for example, the

multiples

2, 4, 8 holes) the injection flow rate will be capable of being varied according to eight successive levels corresponding to the various total numbers of holes being supplied: 0, 1, 2, 1+2, 4, 1+4, 2+4, 1+2+4. If a fourth manifold were to be provided which would then have 8 holes, sixteen injection levels would be available: the eight preceding ones to which there would be added levels with these number of holes: 8, 1+8, 2+8, 1+2+8, 4+8, 1+4+8, 2+4+8, 1+2+4+8. In this way is obtained a sequence of (n+1) manifolds the last one of which has 2 holes, this for 12:0, 1, 2. Thus, by actuating the on-off type control valves, there may be transversely injected into the nozzle any given number of elementary jets of liquid, this number being obtained by combining different powers of two. It is obvious that this method makes it possible to obtain the linear variation desired, which depends directly on the flow rate of the liquid injected, this by the on-off type manipulation of a certain number of valves rather than by the progressive opening of a general valve, as has been the ease hitherto.

It can be arranged, as is shown in the FIGURES 1a, lb and 2, that the manifold 1 is set up for the single unit flow rate or basic flow rate with corresponding injection holes which provide maximum injection speed. The following manifold 2 is planned for double this flow rate, with the orifices being consequently doubled. The third manifold 3 is planned for four times the basic flow rate, to obtain the same injection velocity. Hence, the fourth manifold 4 will provide for eight times the basic flow rate. This arrangement may be continued, each time doubling the flow rate in a general way. By combining the manifolds, a variation in injection flow rate is ob tained and, consequently, a stepped deflection according to, for example, eight successive levels (-with three manifolds) or sixteen levels (with four manifolds). It is thus possible, by adequately controlling the auxiliary flow rate, to bring about a stepped control of the deflection of the jet stream issuing through the rocket nozzle. The reference number 23 (FIGURE 1a) indicates a device for maintaining at a constant value the pressure of the liquid to be injected.

The device exercising control through on-off type valves may be replaced, with advantage, by a suitable slide-valve distribution means. The embodiment illustrated in FIG- URE 3 corresponds to a set of three manifold-s. It includes a cylinder 5, a control shaft 6, an inlet 7 for the deflecting liquid, three

injection outlets

8, 9 and 10 to three

manifolds

1, 2, 3 corresponding to single, double and quadruple flow rates, and a slide-valve carrying seven pistons 11 17 of decreasing thickness. The totality of distinct positions for the distributor makes possible a numerical combination of fractional flow rates in the form of steps from to 7 (FIGURE 4). Every unit combination of flow rate is possible. Variation in the flow rate corresponding to these distinct positions is discrete; it is a stepped function.

In intermediate positions, that is, in those which are not distinct, the distributor provides a linear variation in section as a function of the displacement, if the outlet orifices of the distributor are considered to be in the proportions of one to two to four. The orifices of the distributor and the outlet sections corresponding to these positions are not adjsuted, thus creating a supplementary loss of pressure. The result of this is that in the intermediate positions the flow rate is not linear. The variation in flow rate or the variation in deflection therefore follows a jagged curve the points of which fall in separate positions on the straight line relating to distribution (FIGURE 5). If the method of pilotage requires a precise straight line, in the intermediate positions the pressure upstream of the valve can be reduced to compensate for the loss of pressure. Thus, for an injection set having two or three manifolds, with the distributor described above, there may be put into effect a means of deflection through a variable flow rate, this at a constant injection velocity so as to have linearity in control.

Control of the operation, hence control of the distributor, can be effected by an electronic device 21, the input signal 22 being in binary form.

It is obvious that the invention is not limited to the embodiments explicitly described but that it likewise covers those embodiments which may be obtained by the employment of equivalent technical means and by such other variations as are within the scope of the appended claims.

What is claimed is:

1. In combination with a main nozzle for ejecting a fiuid jet stream, a device for deflecting the said jet stream by the transverse injection of pressurized liquid, such device including:

a source of pressurized liquid,

a plurality of manifold means,

means connecting said manifold means in parallel and to said source,

an on-off type valve means in the connecting means between each of said manifold means and the said source,

and nozzle means arranged on said manifold means and having port in the said main nozzle in a direction which is transverse in relation to the axis of this main nozzle, these nozzle means being distributed over the said manifold means in such a manner that the sections of injection of the respective manifold means are arranged according to successive powers of two.

2. A device according to claim 1, including means for effecting the numerical combination of the fractional flow rates of liquid supplied by the respective manifold means, whereby to modify in a discrete manner the overall flow rate of liquid formed by the sum of the said fractional flow rates.

3. A device according to claim 2 in which the means for effecting the numerical combination and the on'off type valve means includes slide-valve distribution means having an inlet opening adapted for connection to the liquid source, a plurality of outlet openings each adapted for connetcion to a manifold means, and a slide valve adapted to occupy a series of discrete positions, the said slide valve having a plurality of lands adapted to cooperate with the said outlet openings in order to open and close the said openings, whereby they define a numerical combination determined for each discrete position of the slide valve.

4. A device according to claim 2, in which the numerical combination device is controlled by a device sensitive to a binary input signal.

5. A device according to claim 1, in which the nozzle means all have the same dimensions, their number varying from one manifold means to the next according to a geometric progression with the common ratio of two.

6. A device according to claim 1, having means for maintaining the pressure of the liquid constant.

References Cited UNITED STATES PATENTS 3,128,602 4/1964 Salemka 239265.l7

3,229,460 ll/1966 Jones 239-26523 EVERETT W. KIRBY, Primary Examiner.

Claims

1. IN COMBINATION WITH A MAIN NOZZLE FOR EJECTING A FLUID JET STREAM, A DEVICE FOR DEFLECTING THE SAID JET STREAM BY THE TRANSVERSE INJECTION OF PRESSURIZED LIQUID, SUCH DEVICE INCLUDING: A SOURCE OF PRESSURIZED LIQUID, A PLURALITY OF MANIFOLD MEANS, MEANS CONNECTING SAID MANIFOLD MEANS IN PARALLEL AND TO SAID SOURCE, AN "ON-OFF" TYPE VALVE MEANS IN THE CONNECTING MEANS BETWEEN EACH OF SAID MANIFOLD MEANS AND THE SAID SOURCE, AND NOZZLE MEANS ARRANGED ON SAID MANIFOLD MEANS AND HAVING PORT IN THE SAID MAIN NOZZLE IN A DIRECTION WHICH IS TRANSVERSE IN RELATION TO THE AXIS OF THIS MAIN NOZZLE, THESE NOZZLE MEANS BEING DISTRIBUTED OVER THE SAID MANIFOLD MEANS IN SUCH A MANNER THAT THE SECTIONS OF INJECTION OF THE RESPECTIVE MANIFOLD MEANS ARE ARRANGED ACCORDING TO SUCCESSIVE POWERS OF TWO.