US2569996A

US2569996A - Self-adjusting reaction nozzle

Info

Publication number: US2569996A
Application number: US611631A
Authority: US
Inventors: Kollsman Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-08-20
Filing date: 1945-08-20
Publication date: 1951-10-02
Anticipated expiration: 1968-10-02

Description

Oct. 2, 1951 P. KOLLSMAN 2,559,996

SELF-ADJUSTING REACTION NOZZLE Filed Aug. 20, 1945 5 Sheets-Sheet 1 INVENTOR. p404 fleas/14A jrrae/vsy Oct. 2, 1951 P. KOLLSMAN 2,569,996

SELF-ADJUSTING REACTION NOZZLE INVENTOR. 404 /f04. SMA/V,

Maize: fig 4W 4M Oct. 2, 1951 p, KOLLSMAN 2,569,996

SELF-ADJUSTING REACTION NOZZLE -Fi1ed Aug. 20, 1945 3 Sheets-Sheet 5 FULL) CONTRACTED Jim 17.

.2 2 [5, p INVENTOR. 44/4 flous/nm/v 1125.14

Patented Oct. 2, 1951 UNITED STATES PATENT OFFICE SELF-ADJUSTING REACTION NOZZLE Paul Kollsman, New York, N. Y.

Application August 20, 1945, Serial No. 611,631

7 Claims. I

This invention relates to nozzles for converting pressure energy of a gas into kinetic energy, and is particularly applicable to nozzles or rockets and jet engines, nozzles for turbines operated by steam of variable pressure, and other uses Where jets of a compressible fluid are discharged into a space within which the pressure varies, it being understood that the uses must be compatible with the physical characteristics of the structural materials of a nozzle, particularly the resistance of heat.

One object of the invention is a provision of a nozzle for converting pressureenergy of a gas into kinetic energy in which the nozzle walls automatically assume a position providing the substantially maximum delivery of kinetic energy.

Another object of the invention is a provision of a nozzle for converting the pressure energy of a gas into kinetic energy in which the walls of the nozzle are automatically movable substantially to balanc the internal and external pressures thereon to secure substantially the maximum delivered kinetic energy in the discharged gas.

Another object of the invention is a provision of a nozzle in accordance with the preceding objects in which the maximum divergence of the nozzle walls is controlled.

Another object of the invention is the provision of a nozzle in accordance with the preceding objects in which a provision is made for streamlining the variable nozzle exit to facilitate its movement through a gas.

Other objects and features of the invention will be readily apparent to those skilled in the art from the specification and appended drawing i1- lustrating certain preferred embodiments in which:

Figure 1 is a sectional view through a nozzle according to th present invention.

Figure 2 is an end view of the nozzle of Figure 1.

Figure 3 is a sectional view of .a modified form of a nozzle.

Figure 4 is an end view of the nozzle of Figure 3.

Figure 5 is a sectional view of a further modified form of nozzle.

Figure 6 is a View of the nozzle of Figure 5 showing the shape of the .nozzzle with gas passing therethrough.

Figure 7 is a sectional view on the line VII-VII of Figure 6.

Figure 8 is an enlarged detail sectional view through the wall of. the nozzle of Figures .5 and 6.

Figure 9 is a detail showing the contracted and expanded positions of an interior element limiting the divergence of the nozzle wall.

Figure 10 is a modified partial View of a divergence limiter.

Figure 11 is a view partly in section and partly n elevation of a modified form of nozzle includng streamlining of the variable outlet opening.

Figure 12 is a sectional view of a modified form of nozzle wall element particularly adapted for use in curved surface nozzles according to present invention.

Figure 13 is an enlarged transverse sectional detail of the wall of Figure 12.

Figure 14 is a sectional view of a'further modified form of nozzle.

Figure 15 is an end view of the nozzle of Figure 14.

In the form of the invention illustrated in Figures 1 and 2, there is provided a rigid nozzle portion I into which gas flowing from the tube 2 is discharged to efiect conversion of the pressure energy of the gas into kinetic energy. If the pressure differential between the nozzle inlet and outlet for a given gas condition is too great, the energy conversion is not effected throughout the entire length of the nozzle but is incomplete and at the outer portion of the nozzle the gas simply expands to lower its remaining velocity and kinetic energy. After the pressure energy of the gas has been converted into kinetic energy it is desired that there be no further divergence of the nozzle chamber walls so that the gas will continue its movement through a passage of constant width. To effect this change in the surface of the walls defining the nozzle opening there is provided Within the rigid nozzle'portion I a resilient member 3 which is readily flexible in a transverse direction but with its longitudinal length maintained substantially'constant. The walls of the interior member 3 will assume a position where the interior gas pressure is not less than the exterior pressure. As indicated in full lines in Figure 1, the pressure differential between the inlet and outlet of the nozzle is such as to effect the conversion of thepressure energy of the gas into kinetic energy along the tapered nozzle wall only to the plane 4, At this point the interior gas pressure is substantially equal to the exterior pressure assuming the tendencyofthe member 3 to expand. or contract by itself is nonexistent or negligible and the walls of the member 3 beyond plane4 form a cylinder of substantially constant diameter with substantially maximum delivery of kinetic energy of. thegas. The

rigidnozzle portion l determines the angle of divergence of the walls of the member 3 in operation regardless of the pressure difference between the interior and exterior of the nozzle to insure contact of the gas with the nozzle surfaces.

In broken lines in Figure 1 have been illustrated other conditions of operation of the nozzle. Assuming that the inlet and outlet pressure differential is lowered from the full line condition, conversion of energy will be efiected only to the plane 5, and thereafter the member 3 assumes a cylindrical shape to the nozzle outlet. Similarly, should the pressure differential increase, the member 3 will conform to the surface of the rigid portion I to the plane 6, with its final exit portion cylindrical.

In the form of the invention of Figures 3 and 4.

there is provided a rectangular nozzle having its cross-sectional variation produced by flexible metal wall portions. While shown as rectangular, the invention is not limited thereto as other metal wall shapes could obviously be used. As specifically shown in Figures 3 and 4, there is shown a discharge tube 5 formed into a'rectangular shape at the portion 8. walls beyond the portion 8 are discontinued but the parallel side wall portions 9 and H are continued with substantially increasing height toward the outlet. The edges of the side walls 9 and H are inwardly directed at 12 to provide stops. Intermediate of theside walls 9 and H the tube 7 carries ribs 53 and I4 whose inner surfaces diverge and which again form stops. Connecting to the top and bottom walls of the por tion 8 of the tube 7 are flexible metallic walls 15 and I6 forming the top and bottom surfaces of the discharge nozzle. The operation of the nozzle of Figures 3 and 4 is similar to that described for Figures land 2. The flexible walls l5 and it are acted upon by the inside and the outside pressure. In the area within which the inside pressure is greater than the outside pressure the walls rest against the stops l2, l3 and My At the point of equal pressures and beyond this point the walls l5'and l6 continue substantially parallel thus providing a duct of substantially constant cross section. Energy conversionis thus being eifected efficiently within the tapered portion and thereafter further expansion of the gas is avoided by maintaining the internal pressure substantially The divergence of In the form of the nozzle illustrated in Figures 5, 6 and 7, the nozzle is shown as circular in cross-' section and comprised of a pair of concentric resilient tubes formed of a material such as rubber, indicated at I! and 18. These tubes are joined together to form a plurality of circumferentia-lly spaced pockets IS in which are disposed contracted wires or cords 2| of progressively'increasing expanded length from the inlet toward the outlet of the nozzle. The resilient material of the, tubes l'! and 18 is prevented from expanding lengthwiseby longitudinally extending wires 22 shown particularly in Figures 7 and 8.

Figure 9 illustrates the expanded and contracted positions of one of the circumferential elements 2 I.

Figure 10 illustrates a modified form of circumferential element formed of a wire 23 which slides through a hub 24 with a limiting stop 25.

The top and bottom The nozzle asshown in Figure 5 is in its normal position without gas flow therethrough. Figure 6 illustrates the position of the nozzle walls under certain operating conditions in which the gas pressure has been converted to kinetic energy and the internal and external pressures substantially equalized at the plane 26 assuming that the tendency of the nozzle to contract is negligible in relation to the internal pressure. The portion of the nozzle beyond the plane 2% is again cylindrical, as shown in full lines. The divergent angle between the inlet of the nozzle and the plane 26 is determined by the varying overall length of the expanding elements 2| and 23 in the chambers I 9. The position of the nozzle of Figure 6 for full conversion through the entire nozzle length is indicated by the broken plane lines and again this maximum divergence is determined by the progressively increasing length of the expansible elements 2i and 23 from the inlet toward the outlet of the nozzle. v

In the form of the invention illustrated in Figure 11, there is provided a nozzle adapted for movement through a gas in which there is provision for streamlining the variable nozzle outlet. As specifically shown, this form comprises a rigid nozzle portion 27 similar to the nozzle portion lof Figure 1 and within the nozzle there' is disposed the resilient member 28 similar to the resilient member 3 of Figure l but of greater length, extending beyond the outer edge of the rigid portion 21. Exteriorly of the nozzle portion 27 there is provided a second flexible member 29 whose outer edge is adapted to contact member 28 adjacent to its end. v

In the nozzle of Figure 11, the flexible portion 28 will again assume a position providing for the maximum gas kinetic energy. As specifically shown, the internal and external gas pressures are substantially equal at the plane 3| and beyond this plane member 28 assumes a substantially cylindrical form with a constant diameter it being understood that the elastic resistance of the

members

28 and 29 to expansion is negligibly small in relation to the force exerted by the gas on the member 28 producingits deformation t0 the illustrated shape. The surface 29, whose outer edge follows the movement of the member 28, streamlines the ineffective nozzle portion to the flow of gas outside the nozzle. In the absence of the member 29, the ineffective portion of the nozzle between the member 28 and the edge of the rigid member 27 would cause a considerably greater gas drag to nozzle movement. 1

Figures 12 and 13 illustrate a form of metallic wall which may be substituted for the

flexible members

3, 28, and 29 of Figures 1 and 11. This wall 29' is formed of a thin resilient metal, corrugated as indicated more particularly in Figure 13. The particular shape selected by wayof example for the illustration of Figure 12, is that of the member 29 whose outer edge rests freely on the wall of the member 23 without being connected thereto. i I Air is permitted to enter and escape from the space between the

members

28 and 29 by appropriate vents, as are provided, for example, by

= the corrugations with which the member 29rests on the member 28.

In the form of nozzle illustrated in Figures 14 and 15, there is again provided streamlined surfaces for the variable nozzle outlet but in a form utilizing resilient metal walls. There is here shown the gas discharge duct 3i terminating in a diverging rigid nozzle portion 32. The nozzle is illustrated asrectangular but it is understood that other structuralshapes permitting the movement of the'walls may be utilized. The top and bottom interior walls of the nozzle are ,formed by flexible walls-33 and 3,4, "WhlClflwflS illustrated, conform to the interior surface of the rigid portion to the plane 35, at which point the internal and-externalpressures'are substantially equal. The side Walls of the nozzle are shownaaii and,3l. Exteriorly of the discharge ductiand nozzle there is shown a streamlined 'surface38 which may be a structural wall of a :d'evicepin which the nozzleis located, for example. the-surface of an airplane. The streamlining'df the nozzle outlet is efiected between flexible strips 39 and 4| whose outer edges follow-the movement of the resilient walls 33 and (to provide streamline surfaces to eliminate the drag of the ineffective portion of the nozzle out- -let.

While certain preferred embodiments of the invention havebeen speeiflca'lly disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims:

What is claimed is:

1. In a nozzle for converting gas pressure energy into kinetic energy, the improvement which comprises, a flexible wall forming part of the gas passage through the nozzle, said wall being acted upon by the gas pressure on the interior side tending to flex the wall in a direction to increase the cross sectional area of the nozzle if the gas pressure on the interior side is greater than the pressure on the exterior side of the wall, and stop means for limiting the extent to which the wall may be flexed to a predetermined maximum angle of divergence of the nozzle passage towards the discharge end of the nozzle under predominant gas pressure on said interior side, the said wall due to its flexibility being capable of having its end portion, adjacent the discharge end of the nozzle, flexed into a position of substantially constant cross sectional nozzle area under condition of substantial equality of pressure on either side of the wall in which case said end portion, in longitudinal section, extends at an angle with respect to the divergent portion and is spaced from said stop means.

2. An automatically adjustable nozzle for converting gas pressure energy into kinetic energy, the nozzle including an outer rigid housing, and a flexible wall within said housing forming at least a part of the gas passage through the nozzle within which the energy conversion takes place, said flexible wall being acted upon on the interior side by an internal pressure exerted by the gas flowing through the nozzle and on the exterior side by an external pressure, said flexible wall being free under condition of equal pressure on either side to assume a rest position in which the cross sectional area of the nozzle passage portion of which said Wall forms a part is substantially constant, the wall being flexible in a direction to increase the cross sectional area of the nozzle passage towards the nozzle exit under condition of predominant internal gas pressure, said housing including a rigid wall for limiting the extent to which said wall may be flexed to a predetermined maximum angle of divergence of the passage towards the discharge end of the nozzle under action of predominant internal pressure, the flexible wall being sufliciently limp to have its end portion adjacent the discharge end of the nozzle flexed into a position of substantially 6 cons'tantcro'ss sectionalinozzle area und'er-Jthe influence "of :substaritiallyequal internal andjthe external pressure, said last named position being intermediate said rest position and the position of restraint by said rigid wall and-lying at an angle, in longitudinal section, with respect to the position 'of restraint. Y

An automatic adjustable nozzle-for convertin'g gas pressure energy into ll'iinetie energy by ipassage through a divergent passage, the nozzle including a flexible'deformable wall portion lead-- "in to the nozzle discharge end, said wall portion r nal-1y providing a nozzle passage of substanti' "1y constan t cross sectional area, the wall porbei'ng deformable into a position in which ides a divergent nozzle passage portion 0f essively increasing cross sectional area of the passage towards the nozzle discharge end; provision for varying the length of the divergent passage portion'in dependence on'the difierence in-pressure between points inside the nozzle passage and the pressure outside the nozzle passage, the wall portion being capable due to its deformability to assume a position of substantially constant cross sectional passage area adjacent the nozzle discharge end under the compelling influence of the inside and outside pressure acting on the wall; and stop means for restraining said wall portion to a predetermined maximum angle of divergence of the passage portion under predominant interior pressure.

4. An automatically adjustable nozzle for converting gas pressure energy into kinetic energy comprising, an expansible tube; and a constraining outer rigid housing for said tube, the housing having an internal cavity of progressively increasing cross sectional area towards the nozzle exit, the tube being secured to said housing at an area of smaller cross section than that 01' the exit, the tube being expansible against the wall of the cavity under predominating pressure of a gas flowing through the nozzle.

5. An automatically adjustable nozzle for converting gas pressure energy into kinetic energy comprising an expansible tube of substantially cylindrical shape in non-expanded condition; and a constraining outer rigid housing for said tube, the housing having an internal cone-shaped cavity of progressively increasing diameter towards the nozzle exit, the tube being secured to said housing at the entrance portion of the housing, the tube being expansible against the conical wall of the cavity under predominating pressure of a gas flowing through the nozzle.

6. An adjustable nozzle comprising a rigid outer nozzle housing having a small diameter entrance portion and a large diameter body portion, a deformable member inside said nozzle housing secured to said housing with one end at the entrance portion, the said member providing, with its other end a nozzle discharge port of adjustable size depending on its state of deformation; and a deformable cover element secured with one end to said housing at said large diameter body portion and extending with its other end to said member adjacent the discharge port to provide an adiustable tapering wall from said body portion to said discharge port, said cover element having an inherent tension causing its other end to follow said deformable member towards a position of small nozzle size.

i passage through the nozzle, said wall being acted 7 upon by the gas pressure on one side tending to flex the wall in a direction to increase the cross sectional area of the nozzle if the gas pressure on said one side is greater than the pressure on the other side of the Wall; stop means for limiting the freedom of adjustment of the said wall to a predetermined rate of divergence of the nozzle passage towards the nozzle exit provided by said wall in deflected position under predominant gas pressure on said one side, the said Wall having 1 freedom to adjust itself to a position of substantially constant cross sectional nozzle area under condition of substantial equality of pressure on either side of the wall; and a movable cover element secured with one end to said stop means and extending with its other end to said flexible wall adjacent the nozzle exit to provide a tapering surface from said stop means to said flexible wall adapted to reduce drag on the nozzle by an exterior flow of gas'past the nozzle.

PAUL KOLLSMAN.

8 REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS Number Name Date 157,527 Leggett Dec. 8, 1874 301,228 Gillespie July 1, 1884 351,968 Derrick Nov. 2, 1886 384,306 Bourdil June 12, 1888 591,067 Wallace Oct. 5, 1897 1,225,242 Guerin May 8,1917

2,303,992 Frazer et a1. Dec. 1, 1942 2,413,488 Draeger Dec. 31, 1946 2,467,150 Nordell Apr. 12, 1949 2,472,949 Jackson June 14, 1949 2,486,967 Morrison Nov. 1, 1949 FOREIGN PATENTS Number Country Date 612,783 France Aug. 7, 1926