AU745411B2

AU745411B2 - Device for increasing the power of media flowing along a body at a high speed or a very fast moving body in a medium and use thereof as a high pressure nozzle

Info

Publication number: AU745411B2
Application number: AU32538/99A
Authority: AU
Inventors: Charles Loegel
Original assignee: MORITZ HELMUT
Current assignee: MORITZ HELMUT
Priority date: 1998-05-13
Filing date: 1999-02-23
Publication date: 2002-03-21
Anticipated expiration: 2019-02-23
Also published as: ATE239553T1; AU3253899A; EP1079935A1; CA2312425A1; DE59905470D1; DE19821449A1; KR20010032484A; EP1079935B1; WO1999058250A1; JP2002514500A

Abstract

In order to increase the power of fast flowing media, the wall surface (2) of a solid body (1) along which the medium flows, is provided with a plurality of recesses (3; F1, F2, F3) that extend by at least one length (1) in the direction of flow (SR) at a depth (t) that is substantially lower than the length thereof (1). At least parts of the recesses (3) have a depth (t) that diminishes in the direction of flow (SR) along said wall surface and the recesses form at least one interruption in the wall surface (2) in the direction of flow. The device can be used to particularly advantageous effect in high pressure nozzles in order to produce a high pressure liquid jet in pipelines, suction tubes for carburettors, exhaust gas tubes and in projectiles such as rockets which can move very quickly through a medium.

Description

DEVICE FOR INCREASING THE POWER OF MEDIA FLOWING ALONG A BODY AT A HIGH SPEED OR A VERY FAST MOVING BODY IN A MEDIUM AND USE THEREOF AS A HIGH PRESSURE NOZZLE The invention relates to a device for increasing the power of media flowing fast along the wall surfaces of a body or, conversely, bodies moving very fast in a medium as well as uses of the device.

Such devices have already been known for high pressure nozzles in order to produce a high pressure liquid jet (US 1,703,029, EP-A-O 121 951 and DE-A-3 443 263). It is often desirable not to spread the so-called "jet angle" of the medium jet exiting from the nozzle too far, but to keep it as narrow as possible.

In narrow high pressure jets, the energy content per surface unit of the jet area is, as a rule, higher than in a very far spread or, respectively, an atomizing jet. The efficiency of the fast flowing gas or liquid is improved by channels extending axially along the nozzle opening in the lateral area or, respectively, the inner wall surface of the nozzle bore.

It is the object underlying the invention to further improve the power or, respectively, efficiency. It is not only the improvement of the "energetic", efficiency of the jet impinging on an object which is considered, but other efficiencies of media flowing fast in tubes and hoses, for instance, or of bodies oving very fast in media are to be improved as well; this it possible to improve the energy expenditure for the 2 transport of the flowing medium or a rocket, for instance, or to increase the velocity thereof, respectively.

According to a first aspect of the present invention there is provided a device for increasing the power of media flowing along the wall surfaces of a solid body and, more particularly, media being under high pressure and/or solid bodies moving very fast in a medium, wherein at least one wall surface of the a solid body limits the relative flow between the medium and the solid body on at least one side and guides it in a specific direction, while forming a certain flow resistance, and wherein the wall surface comprises a plurality of recesses extending at least over a length in the direction of flow, whose depth is substantially smaller than their length characterised in that at least part of the recesses have a depth diminishing in the direction of flow along the wall surface and that the recesses form at least one interruption of the wall surface in the direction of flow.

020 According to a second aspect of the present invention there is provided a high pressure nozzle for producing a high pressure liquid jet having an insert of a hard material, in particular, whose passage opening determines the jet of the exiting liquid, and an attachment sleeve or bushing through the flow channel of which the liquid being under high pressure may be supplied to the passage opening of the insert, wherein the flow channel comprises an average cross-section diminshing in the direction of flow with an opening angle against the direction of flow, characterised in that the flow channel comprises axial grooves in the inner lateral area which extend in the direction of flow and terminate at an interruption of the H:\HelenF\Keep\speci\32538.99Speci.doc 18/01/02 2a wall surface in the direction of flow, in the form of a retaining shoulder of the insert, and whose depth diminishes in the direction of flow.

Preferred configurations of the invention are explained in detail upon reference to the following specification and the drawings.

The invention makes it possible to improve the power of the medium flowing along the wall surface at high speed or the efficiency of a body moving very fast through a medium in a surprising manner: although the wall surface in the direction of flow is not smooth, but definitely uneven *(since recesses are disposed therein), the power is improved.

According to the general principle of the present invention, at least one wall surface of a solid body, laterally limiting the fast flowing medium and guiding it 20 in a specific direction, is provided with a plurality of recesses extending at least over a length or, respectively, distance in the direction of flow, whose depth is substantially smaller than their length. The depth of the recesses is preferably 0.01 to 2 mm, more particularly 0.1 0.8 mm. Such recesses are preferably formed as groove-shaped recesses in the manner of axial grooves which do, however, not extend over the whole length of the wall surface in the direction of flow, but whose length is substantially smaller than the length of the respective wall surface so that several such recesses are spaced apart from each other "one behind the other".

The depth of part of the recesses, at least, diminishes in the direction of flow. The recesses may lead to a H:\Helen\Keep\speci\32538.99Specidoc 18/01/02 2b retaining site in the flow channel or may form certain "retaining sites" themselves so that the flow resistance of the medium changes in the direction of flow and, more particularly, alternates several times between different values.

If the wall surface of the solid body is formed as the inner lateral area of a tube, it is recommended to form the recesses into the lateral tube area such that they constitute marked e S H:\Helen\Keep\speci\32538.99Speci doc 18/01/02 i~ JI-- ll ~i.LII:_21. guiding edges substantially in the direction of flow and are distributed as uniformly as possible over the periphery of the flow channel. It has been shown that at least four, better five or six such axial grooves should be disposed in the flow chan- -nel for high pressure water jet nozzles having a small passage cross-section whereas even more, e.g. twelve axial grooves should be provided for fire extinguishing lances having higher passage cross-sections.

It has been shown that the sum of the surface portions on the -respective wall surface, which are constituted by recesses, should be higher than 1 in proportion to the sum of the wall surface portions which do not correspond to recesses. The proportion of the surfaces associated with the recesses is preferably 0.7, more particularly 0.8 and 0.9 with respect to the overall surface, whereby the "roughness" of the wall surface becomes very strong.

Moreover, it is recommended to make the flow area of the flow channel diminish in the direction of flow so that there results an opening angle a between 10 and 130, more particularly between 2.80 and 3.80 against the direction of flow of the medium.

A substantially greater improvement may be achieved if an additional abrupt flow resistance is generated at the end of the flow channel by a small retaining or impact shoulder before the medium flowing from said flow channel enters a passage opening, having a substantially smaller cross-section, of a nozzle insert of a hard material, in particular, through which the jet then exits from the nozzle.

An arrangement of the axial grooves having a star-shaped crosssection leads to favourable results.

~Thus, it has been shown that the power of a narrow high preso6-sure water jet produced according to the invention could be im- <proved, completely surprisingly, by approximately 350 %over a water jet produced with conventional high pressure nozzles at the same water pressure of 1200 bar. For instance, if a slot is provided in rock formations with a conventional high pressure nozzle having a cylindrical inner cross-section of the flow channel under the above-mentioned pressure and with a flow rate of 10 1/mmn water, a "cutting power" of 2 m 2 /h is achieved at a specific slot depth. If this known nozzle is replaced with a nozzle formed according to the invention, there not only results a higher flow rate between 11 and 11.5 1/mmn water at the same pressure, but also a cutting power of 7 m 2 /h is achieved for the same rock and under the otherwise same conditions. In comparison with the conveying rate of 2 m 2 /h in the case mentioned first, thi~s means a multiplication by However, the invention may also be applied to other fields, e.g. for pipeline tubes and turbines whose inner jacket is provided, around the periphery, with such flat recesses extending in the axial direction and being spaced apart from each other in said direction. The invention is also applicable to turbine blades and guide blades of other turbo-machines.

There also result considerable improvements when the inner surfaces of suction tubes and manifolds of car or other carburettors are provided with corresponding recesses which are not too deep. The invention is also applicable to exhaust gas tubes and exhaust elbows so that there surprisingly result improvements of several percent in view of reduced fuel consumption with better output power in the field of internal combustion engines of motor vehicles, in particular. This result is completely surprising since one had hitherto considered that the wall and baffle surfaces exposed to the flowing medium should be configured to be as even as possible.

The reason for the surprising results has not been analysed sufficiently yet in theory nor science. It is assumed that :!1-re occur boundary layer effects, i.e. that the invention inuences the boundary layer between the f lowing medium in the lion )ionnear the lateral area, on the one hand, and in regions more remote f rom the lateral area on the other hand such that there occurs a more efficient distribution between the laminar and turbulent flows and that less energy is withdrawn from the medium f lowing along the lateral area or, respectively, the baffle and flow surface although one had to assume prima facie that such "interruptions" of the wall surfaces or, respectively, the lateral areas achieve the opposite. Surprisingly, less kinetic energy, for instance, is withdrawn from the f lowing medium in the invention. It is assumed that the so-called transition line may be displaced far downstream by the invention, which helps in promoting the discontinuity surface in potential flows. Turbulent effects are reduced.

It is correspondingly recommended to use the invention for flow surfaces of aircraft and, above all, very fast flying missiles like rockets wherein the medium surrounding these bodies certainly need not flow fast itself, but may stand still. However, since the fast moving body has a high velocity, there also results a corresponding effect at the boundary layer between the medium liquid or gas, on the one hand, and the body on the other hand.

Embodiments of the invention will be explained in detail upon reference to the drawing; therein: Fig. 1 is a schematic part-longitudinal section through a high pressure water jet nozzle in the longitudinal direction and fig. la shows part of a cross-section through the nozzle in respectively enlarged representation; Fig. 2 is a schematic aspect of an inner lateral tube area serving as a wall surface and comprising a system of lozenge-like flat recesses in the wall surface; Fig. 3 is a longitudinal section through a high pressure nozzle; Viq 4 is a cross-section according to A-A of fig. 3 and Fig. 4a is an enlarged part-section thereof; Fig. 5 is an enlarged detail of the transition between an attachment bushing and a following hard material insert of the HP nozzle under flow conditions; Fig. 6 is another cross-section of the flow channel of the attachment bushing; Fig. 7 is a schematic cross-section through a pipeline tube and a partial aspect of its inner lateral area; and Fig. 8 is a schematic cross-sectional drawing of an aircraft wing.

Fig. 1 shows the longitudinal section through a part of a solid body 1 configured as a nozzle tube, which may consist of hard steel, for instance. The inner lateral area of tube 1 having the diameter D constitutes the wall surface 2 for the medium, e.g. water, flowing very fast through the tube cross-section.

In contrast to the conventional configuration of the wall surface 2 which is smooth or merely interrupted by axial longitudinal grooves, the wall surface 2 according to the invention is interrupted by numerous recesses 3 spaced one behind the other in the direction of flow which have, in this example, an approximately lens-shaped cross-section and extend into the material of tube 2 with a maximum depth t 0.3 mm, namely not over the whole axial length of tube i, but merely over a length being about five to fifty times the depth t. According to fig.

la, these recesses 3 may be configured in the form of a notch having an approximately triangular cross-section with a notch angle 0 of between 80 and 1000, in particular. The base or, respectively, the bottom of notch-like recesses 3 extends, as bottom line 4, substantially in the axial direction or, respecvely, the flow direction SR of tube 1 and adopts, in the lonudinal section, the lens-shaped form shown in fig. 1, ereby respectively part of the respective recess comprises a I ,--Ths ?AA.A,.AA. depth t diminishing in the direction of flow SR along wall surface 2. Therefore such recesses 3 are disposed to be spaced apart in the direction of flow on wall surface 2, one behind the other. Also, such recesses 3 are distributed over the periphery of the inner lateral area or, respectively, wall surface 2; these recesses are indicated merely symbolically in fig. 1 by recess lines 3'.

According to fig. 2, the inner lateral tube area 2 is constituted by a net-like system of webs 2' which, in an aspect seen from the tube interior, keep lozenge-like recesses 3 spaced apart from each other, which in their turn comprise bottom lines 4 substantially extending in the direction of flow SR; these bottom lines 4 respectively connect those lozenge corners of each lozenge which are spaced farthest apart. In this configuration of the invention, the greater part of the wall surfaces is occupied by recesses 3 whereas the sum of webs 2*, which constitute the actual wall surface 2, is substantially smaller in comparison. Since very narrow webs 2' are used, the sum of the recesses 3 projected onto the wall surfaces becomes substantially larger, with about 80 to 95 of the overall inner lateral tube area, than the remaining wall surface 2 constituted by webs 2'.

According to fig. 3, high pressure water nozzle D comprises a screw insert 10 made of INOX, i.e. stainless steel, for instance, into which an annular insert 5 of a hard material like sapphire, in particular, is glued, whose passage opening 6 comprises a diameter d of about 1 mm. In the direction of flow, an attachment bushing 7 is disposed before insert 5, which is to be considered a body 1 whose wall surface 2 diverts the flow of the liquid, water in the present case, led through it under high pressure. The diameter D of flow channel 8 is substantially larger, i.e. 1.5 mm, than diameter d in the region of the transition towards the cylindrical passage opening 6 of insert 5 so that a retaining or, respectively, impact shoulder 9 >s s formed at that transition, which prima facie further in- "reases the flow resistance.

Furthermore, f low channel 8 comprises an opening angle a against the direction of f low SR. This opening angle should be between 2 and 130; an especially preferred opening angle is 3- Moreover, the flow channel 8 is configured to have a hexagonal cross-section according to fig. 4, meaning that it comprises six axial grooves (Fl, F2, F3 having relative sharp guide edges 4 which extend in the axial direction or, respectively, the direction of flow SR. According to the length 1 of flow channel 8, the depth t of these axial grooves is about 0. 1 to 0.8 mm at the entrance end of flow channel 8 so that the abovementioned opening angle is respected, and diminishes to zero towards retaining shoulder 9 at insert Fig. 4a represents a schematic cross-section of the upper half of attachment bushing 7 shown in f ig. 4 in order to illustrate that axial grooves Fl, F2 etc. are formed due to the hexagonal cross-sectional structure of the inner lateral areas, which are generated in the region of recesses 3 between the even portions of the inner lateral tube area and the imaginary semicircle which would be generated in the known cylindrical or, respectively, conical cross-sections of the flow channel 8 of such attachment bushings 7. This semicircle does not exist in the invention because recesses 3 are pressed or milled into body 1 of bushing 7 or carved out therefrom in any other manner.

Therefore the depth t of recesses 3 is measured from this semicircle to the "groove base" which is constituted by edge 4 of the respective notch-shaped axial groove Fl, F2, which extends in the longitudinal direction. The surfaces of axial grooves F1, F2, F3 preferably also comprise recesses 3 of the type shown in fig. 1 or 2, which is not shown in fig. 3, but indicated in fig. 4a.

ig. 5 indicates the expected course of the flow pattern of the ~owing medium which leaves the nozzle or, respectively, insert tt"as a jet S. It is assumed that a thin "boundary layer" is disposed about the "core" of jet S, which opposes a certain resistance to the widening of the "core" transversely with respect to the jet direction SR and thereby "holds" the energy of the liquid jet "together" in a small region with the abovementioned effect of an improved efficiency and higher kinetic energy density.

According to fig. 6, the cross-section of flow channel 8 is not hexagonal, but star-shaped. The axial grooves or, respectively, recesses 3 have an approximately triangular cross-section; they protrude from the approximately conical clearance zone of flow channel 8 into the material of body i, i.e. attachment bushing 7.

The cross-section of flow channel 8 selected according to the invention is for instance produced in that a polygonal tool is pressed or, respectively, driven into a bushing or sleeve 7 having a conical flow cross-section so far that there result the cross-sectional shapes of figs. 4 to 6 with the recesses 3 or, respectively, axial grooves Fl, F2, F3 formed thereby.

Pocket-like recesses 3, which extend in a planar manner over a length 1 far in the axial direction or, respectively, flow direction SR of the tubular body 1 of fig. 7, constitute concave recesses, for instance, whose width b should be less than the length i, but noticeably larger than their depth t.

Fig. 8 indicates that it is expedient to dispose the abovementioned recesses 3 at least on that wall surface 2 of the body 1 serving as an aircraft wing where the air flow is diverted in the direction of flow SR. Surprisingly, the flow about wall surface 2 on the respective part of the upper side of the wing is promoted such that, on the whole, a more efficient flow about the wing may be achieved in order to obtain a low-separation and, therefore, also a more eddy-free course of he air flow as it flows about the profile. The optimum depth, osition, dimension and number of recesses may be determined by .ome tests in dependence upon the shape of the wing profile and 10 the velocity at which the aircraft flies or, respectively, at which the air flowing about the wing moves.

in this specification, except where the context requires otherwise, the words "comprise", "comprises", and '"comprising- mean "include", "includes", and "including", respectively. That is, when the invention is described or defined as comprising specified features, various emibodiments of the same invention may also include additional features.

a a. a a a a.

p a a a a. a a.

a H:\HelenF\Keep\speci\32538.99Specidoc 18/01/02

Claims

1. A device for increasing the power of media flowing along the wall surfaces of a solid body and, more particularly, media being under high pressure and/or solid bodies moving very fast in a medium, wherein at least one wall surface of the a solid body limits the relative flow between the medium and the solid body on at least one side and guides it in a specific direction, while forming a certain flow resistance, and wherein the wall surface comprises a plurality of recesses extending at least over a length in the direction of flow, whose depth is substantially smaller than their length characterised in that at least part of the recesses have a depth 15 diminishing in the direction of flow along the wall .*surface and that the recesses form at least one *.:interruption of the wall surface in the direction of flow.

2. A device according to claim 1, characterised in that the length of the recesses in the direction of flow along the wall surface is substantially smaller than the overall length of the respective wall surface limiting the flow. A device according to claim 1 or 2, characterised in 25 that the body is formed as a tube and the recesses are formed as notches in the inner lateral tube area constituting the wall surface.

4. A device according to any one of the preceding claims, characterised in that the recesses comprise guiding edges extending in the direction of flow. A device according to claim 4, characterised in that ZI-1--7 R'H:\Helenl'\Keep\speci\32538 .99Speci .doc 18/01/02 12 the recesses are disposed in a star shape in the cross- section of the tube.

6. A device according to any one of claims 1 to characterised in that the depth of the recesses is between 0.01 and 2 mm.

7. A device according to claim 6, characterised in that the depth of the recesses is between o.1 and 0.8 mm.

8. A device according to any one of the preceding claims, characterised in that the opening angle of a wall surface conically tapered in the direction of flow is •between 2.8 and 3.80. 1 9. A device according to any one of the preceding claims, characterised in that the sum of the surface proportions occupied by recesses is larger than the sum of o. surface proportions not occupied by recesses on the wall 20 surfaces.

10. A device according to claim 9, characterised in that the sum ratio between the sum of the surface proportions occupied by recesses and the sum of surface proportions not occupied by recesses on the wall surfaces is higher than 0.7.

11. A device according to claim 10, characterised in that the sum ratio is between 0.8 and 0.95 and the recesses on the wall surface are substantially separated by small webs only.

12. A device according to any one of the preceding R-4 RAe, H:\HelenF\Keep\speci\32538.99Speci.doc 18/01/02 13 claims, characterised in that the wall surface is interrupted by a system of recesses being offset with respect to each other and being lozenge-shaped in the surface layout on the wall surface.

13. A device according to any one of the preceding claims, characterised in that the recesses are formed to have a triangular cross-section with a notch angle between and 1000.

14. A high pressure nozzle for producing a high pressure liquid jet having an insert of a hard material, in particular, whose passage opening determines the jet of :4 the exiting liquid, and an attachment sleeve or bushing 15 through the flow channel of which the liquid being under high pressure may be supplied to the passage opening of the insert, wherein the flow channel comprises an average 4 cross-section diminshing in the direction of flow with an :opening angle against the direction of flow, characterised 0000 20 in that the flow channel comprises axial grooves in the 00*0 inner lateral area which extend in the direction of flow and terminate at an interruption of the wall surface in the direction of flow, in the form of a retaining shoulder

44.: of the insert, and whose depth diminishes in the direction of flow. A nozzle according to claim 14, characterised in that the opening angle of the flow channel of the attachment bushing is between 2 and 4'. 16. A nozzle according to claim 14 or 15, characterised in that, in order to form the retaining shoulder, the diameter of the passage opening of the insert is ~,cj RA~,H:\HelenF\Keep\speci\32538.99Specidoc 18/01/02 7 14 S 0 *0 0 0 0* *5 S 0 S 00 S substantially smaller than the average cross-section of the flow channel at the transition to the insert. 17. Use of the device according to any one of claims 1 to 13 for pipeline tubes. 18. Use of the device according to any one of claims 1 to 13 for carburettors for internal combustion engines in the suction pipe or suction manifold. 19. Use of the device according to any one of claims 1 to 13 for internal combustion engines in the exhaust gas tube or in exhaust manifolds. 20. Use of the device according to any one of claims 1 to 13 for aircraft, on flow surfaces thereof, or for missiles like rockets. 21. Use of the device according to any one of claims 1 to 20 13 for turbines. 22. A device for increasing the power of media flowing along the wall surfaces of a body substantially as hereinbefore described with reference to the accompanying figures. H:\HelenP\Keep\speci\32538.99Speci.doc 18/01/02 is 23. A high pressure nozzle for producing a high pressure liquiid jet substantially as hereinbefore described with reference to the accompanying figures. Dated this 18th day of January 2002 HELMUT MORITZ and CHARLES LOEGEL By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia 00 000 0 0O 0 0 00000 000 00@0 0 0 00 00 0 000 0 000 00 0 00 00 0 00 00 0 0 0 0 00 0 6O 00 0 0000 0 0 0000 0 @00000 0 0000 0 0 0000 0 000000 0 00 0 00 00 0 H:\HelenF\Keep\speci\32538.99Speci doc 18/01/02