US3542291A - Streaming - Google Patents

Description

United States Patent lnventor Nathaniel Hughes Beverly Hills, California Appl. No. Filed Patented Assignee Nov Ene 734,089 June 3, 1968 24, 1970 rgy Sciences, Inc.

El Segundo, California a corporation of California STREAMING 4 Claims, 3 Drawing Figs.

U.S. Cl

Int. Cl

1llllllll 50 Field olSearch 239/411, 102; 116/133; 181/.5

[56] References Cited UNITED STATES PATENTS 3,337,135 8/1967 Blakely etal. 239/102 3,240,253 3/1966 Hughes 239/102X Primary Exan1ir1erM. Henson Wood, .lr. Assistant ExaminerGer1e A. Church Att0rney-William W. Rymer, Jr.

ABSTRACT: Streaming to supersonic speeds with small nozzles using boundary layers to define effective nozzle surfaces and inlet end implosion of gas at greater than environmental pressure to intensify shock power at the nozzle outlet.

STREAMING This invention relates to streaming at supersonic speeds using small nozzles in which effective nozzle surfaces are defined by boundary layer effects, and represents an improvement on the subject matter of the pending application of Nathaniel Hughes, Ser. No. 718,447, filed Apr. 3, 1968, now US. Pat. No. 3,531,048, Supersonic Streaming", the contents of which are hereby incorporated by reference herein.

An object of the invention is to increase the intensity of the shock process at the outlet of nozzles embodying the invention of said Hughes application and to provide more effective sculpturing of the effective nozzle surfaces. Other objects include increasing the volume of flow in the boundary layer, and the operating pressure range of the nozzle.

In general, the invention features implosion at the nozzle inlet of gas of greater than environmental pressure into a zone intermediate the main flow stream and the inner surface of the nozzle. In preferred embodiments there is featured introduction of both a liquid and a gas upstream of nozzle inlet hole and of implosion passageways adjacent thereto, as well as of injection through throat plane stabilization holes of gas and liquid moving through said passageways.

Other objects, features, and advantages will appear from the following description of a preferred embodiment of the invention, taken in conjunction with the drawings, in which:

FIG. 1 is a perspective view, partially in section, from a first point of view, of said preferred embodiment;

FIG. 2 is a perspective sectional view, taken at 2-2 of FIG. 1, from a second point of view of said embodiment; and

FIG. 3 is a sectional view, taken at 3-3 ofFlG. 1.

Referring now to the drawings, there is shown in FIG. I a nozzle unit indicated generally at 10, and including a housing 12 and a body 14.

Both housing 12 and'body 14 are formed of free-machining brass, and the interrupted cylindrical outer surface of the latter press-fittedly engages the cylindrical inner surface of the former.

The housing 12 bears threads 16 for use in connecting the device in line with a source of air pressure and opposed parallel flat surfaces 18 to facilitate application of a wrench to the device.

Body 14 includes inlet portion 20 including, coaxial with said body, nozzle feed hole 22 and inlet hold 24, the downstream end of the latter lying in the nozzle inlet plane. Downstream of said plane, the body 14 includes boundary layer confining wall 26. The outer surface of body 14 is circumferentially relieved over most of said confining wall 26, but not at the downstream extremity thereof, which is left unrelieved to form circumferential housing engaging ring 28. Four holes 30 with centerlines spaced 90 and all lying in the same plane perpendicular to the body 14 axis extend through confining wall 26.

The wall 26 defines with the inner surface of housing 12 and with the ring 28 a manifold 32 fed through the zones defined between flats 34 of the inlet portion 20 and the housing 12 inner surface.

Two symmetrical circle segments, defined by flats 34 of inlet portion 20 and the inner surface of wall 26, lie in the plane (perpendicular to the body 14 axis) at the upstream end of wall 26.

Wall portion 26 terminates at its downstream inner surface in 45 countersink 38. I

The inner surface of wall 26 and inlet hole 24 are concentric to within 0.001 inch.

In operation, air at a low pressure is introduced into the housing 12 at its threaded upstream end. Part of the air then passes through nozzle feed hole 22 and nozzle inlet hole 24 into the nozzle proper, which is defined by boundary layer confining wall 26. Another part of the air moves through the two zones, segments of circles in transverse cross section, alongside the parallel and opposed flats 34, to be divided then by the wall 26. Part of the air passes through the two symmetrical circle segments 36 into the nozzle, to enhance boundary layer flow and energy and the work done by the outlet shocks.

The remainder moves outside wall 26 into manifold 32 and thence through holes 30 to stabilize the plane of the throat of the nozzle sculpted in boundary layer in the manner taught in the said patent application.

As the air moves downstream from the nozzle inlet plane, the boundary layer thickness rapidly increases, to effectively define the converging portion of a converging-diverging supersonic nozzle. The holes 30 are placed with their axes in the plane at which the effective nozzle diameter is smallest, the throat, at which air speed is transonic. Downstream of the throat the supersonic speeds cause steady boundary layer thickness decay, to define effectively the diverging portion of the supersonic nozzle. Countersink 38 at 45 facilitates jet entrance to the atmosphere.

Nozzle parameters are calculated in the manner set forth in said pending application.

The desired power (the product of nozzle inlet pressure P, and flow rate V, often expressed in cubic feet per minute 'C.F.M.) is first chosen by fixing P,- and V to give the desired P,-

V. The desired jet outlet pressure P, is then selected. Using standard thermodynamic One-Dimensional Isentropic Compressible Flow Functions tables, the matching ratio of effective nozzle outlet area (A,,) to effective throat area (A is selected. Nozzle length from inlet plane to holes 30 centerline L and overall length L downstream of the inlet plane are then selected to give the appropriate, owing to boundary layer growth and decay for the nozzle inside diameter D, chosen, effective throat diameter D and outlet diameter D,,.

In the preferred embodiment, the parameters are:

L*0.152 inches.

L0.255 inches.

D ,,0.103 inches.

D *0.067 inches.

D;0.260 inches.

Hole 30 diameter0.062 inches. Hole 24 diameter-0.076 inches. Hole 24 length-0.025 inches.

The resultant supersonic jet is useful for many purposes, e.g., atomization, as taught in said pending application.

Provision of forced subsonic implosion from the air source through the segment-in-cross section passages alongside flats 34 and at 36 greatly increases the energy of the boundary layer and the force of the supersonic implosion into the emerging supersonic jet.

A liquid may be separately added to the air or other gas upstream of threaded end 16, as by means of a simple tee, in a gas-liquid weight ratio of, say, 1 to 4 or 5. Mixing begins through a rotary action that begins even upstream of hole 22, and continues therein. Inlet hole 24, as ordinarily, triggers nozzle operation. Although the passageways alongside flats 34 are larger in cross-sectional area than inlet hole 24, flow rate per unit area is much less in the nozzle inlet plane than at said passageways than at hole 24, because of the differing respective effects of adjacency of the slower boundary layer and of the faster central nozzle portion. In the nozzle, within wall 26, the liquid portion moves, with the swirling motion, by centrifugal force into the boundary layer. More liquid enters the boundary layer, with gas, through holes 30. All this liquid entering the boundary layer helps to form it up with less gas use,

freeing more gas for work in the supersonic central portion of the nozzle. Furthermore, the liquid increases the momentum of the boundary layer molecules'emerging from the nozzle, and thus intensifies shock, increasing work done. Shock intensification is further dramatically increased by raising P by a factor of almost the square of the amount by which P, exceeds ambient or environmental pressure. Such great action results that chemical reactions, including burning, take place with great intensity suggesting even molecular breakdown owing to shock prior to reaction.

Furthermore, greatly increased self-regulating qualities inhere in the usage just described. With the gas supplied from a I claim:

1. A nozzle device comprising:

a generally cylindrical boundary layer confining wall with inlet and outlet ends;

an element defining a portion defining an inlet hole of lesser diameter than said wall generally alined with the inlet end of said wall and coaxial therewith, said inlet hole being separated radially from said wall by an implosion zone; and

a conduit connecting said zone to a source of greater than environmental pressure.

2. The nozzle device of claim 1 in which said inlet hole is connected to said source of pressure.

3. The nozzle device of claim 2 in which said wall includes a multiplicity of throat plane stabilization holes and said hole are connected to said source of pressure.

4. The method of treating a liquid with the device of claim 3 which comprises injecting it into gas from said source of pressure before said gas enters said inlet hole, said implosion zone, and said throat plane stabilization holes.

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