US3644055A

US3644055A - Fluid-motion apparatus

Info

Publication number: US3644055A
Application number: US863205A
Authority: US
Inventors: Raymond C Davis
Original assignee: Ingersoll Rand Co
Current assignee: Ingersoll Rand Co
Priority date: 1969-10-02
Filing date: 1969-10-02
Publication date: 1972-02-22
Anticipated expiration: 1989-02-22

Abstract

Fluid compressor, pump, or like fluid-motion apparatus having rotor with blades interposed in a housing chamber intermediate the fluid inlet and discharge ports. The blades have relieved areas formed in the lateral edges thereof which interface a wall of the chamber to communicate a high-fluid pressure zone on the one side of said blades with a low-fluid pressure zone at the other side of said blade, thereby to control the fluid boundary layer. Further included is a diffuser with similarly relieved areas in the vanes thereof to communicate the disparate pressure zones to either sides of the vanes.

Description

Unite States Patent Davis Feb. 22, 1972 [54] FLUID-MOTION APPARATUS 211 Appl.No.: 863,205

[52] 0.8. CI. AIS/211, 415/D1G. l [51] Int. Cl ..F04d l/00, F04d 17/08 [58] FieIdofSearch ..4l5/211,119,18l,182,213, 415/212, DIG. l

[56] References Cited UNITED STATES PATENTS 1,622,930 3/1927 Karman et al ..415/D1G. 1 2,819,838 1/1958 Warner ...415/DIG 1 2,847,941 8/1958 Jackson 415/DIG. 1 3,068,799 12/1962 Lock ..415/72 1,924,621 8/1933 Mueller 415/212 1,350,927 8/1920 Gomborow... 415/119 2,819,838 1/1958 Wamer..... 415/211 2,847,941 8/1958 Jackson ....415/l82 2,967,013 1/1961 Dallenbach et a1. ..415/l81 3,433,403 3/1969 Gerlitz ..4l5/ l 82 FOREIGN PATENTS OR APPLICATIONS 152,689 10/1920 Great Britain ..4 1 5/211 579,770 8/1946 Great Britain... .....4l5/2ll 583,664 12/1946 Great Britain... .....4l5/119 636,290 4/ 1950 Great Britain ..4 1 5/21 1 Murphy [57] ABSTRACT Fluid compressor, pump, or like fluid-motion apparatus having rotor with blades interposed in a housing chamber intermediate the fluid inlet and discharge ports. The blades have relieved areas formed in the lateral edges thereof which interface a wall of the chamber to communicate a high-fluid pressure zone on the one side of said blades with a low-fluid pressure zone at the other side of said blade, thereby to control the fluid boundary layer. Further included is a diffuser with similarly relieved areas in the vanes thereof to communicate the disparate pressure zones to either sides of the vanes.

9 Claims, 3 Drawing Figures PAIENTEDFEB 22 I972 Pas 3o 1'- FIG.

HIGH PRESSURE SIDE LOW PRESSURE SIDE INVENTOR RA YMO/VD 6. 0A W3 fizz FLUID-MOTION APPARATUS This invention relates to fluid-motion apparatus, such as compressors, pumps and the like, and in particular to such apparatus having bladed rotors and vaned diffusers and means for controlling the fluid boundary layer of the blades and vanes, and further and individually to such rotors and diffusers for use in fluid-motion apparatus.

Conventional fluid-motion devices comprise a bladed rotor rotatably mounted with a shaft, the blades turning in a casing or housing in a given walled chamber which chamber communicates a fluid inlet with a fluid discharge port.

In addition, where the apparatus employs a diffuser, such a diffuser normally comprises a vaned annular, structure disposed about the rotor, interposed in another chamber interposed between the discharge port and the rotor.

The operating range of such conventional compressors and pumps is limited because the entering direction of the flow relative to the blades of the rotor, and the vanes of diffuser, changes with flow rate. That is, the flow entering direction, relative to the blades and vanes, is a function derived from the flow rate or velocity and the rotor velocity. The flow direction is the vectored angle resulting from these two velocities. A change in the relative direction of the flow from the designed blade and vane angles, i.e., the optimum blade and vane angles, is accompanied by a loss in fluid pressure due to the thickening or buildup of the boundary layer upon the highprcssure side of the blades and vanes, In the case of a compressor, the minimum flow limits occur when the boundary layer separates from the blade surface and causes stalling of the blade and vane airfoils, and results in a surging compressor output. In the case of pumps, the thickening of the boundary layer reduces the slope of the pressure flow characteristic.

It is an object of the present invention, therefore, to teach a fluid-motion apparatus having means for increasing the operating range thereof by controlling the boundary layer which builds upon the surfaces of the blades ofa rotor and the vanes of a diffuser comprised thereby.

Another object of this invention is to provide an apparatus of the type noted having a bladed rotor, and comprising means for communicating a high-pressure-fluid side of each rotor blade with the low-pressure-fluid side thereof.

Another object of this invention is to provide an apparatus of the type noted having a vaned diffuser, andcomprising means for communicating a high-pressure-fluid side of each diffuser vane with the low-pressure-fluid side thereof.

Yet another object of this invention is to teach the provisioning of individual rotors and diffusers, for use with fluid compressors, pumps, and like fluid-motion apparatus, which have means for communicating between otherwise distinctly separate high-pressure-fluid and low-pressure-fluid sides of the blades and vanes, respectively, thereof which, in cooperation with walled chambers in which they are disposed, define, therebetween, substantially separate fluid pressure zones with longitudinally extending fluid passages,

A feature of the present invention comprises the provisioning of the rotor blades and the diffuser vanes with relieved areas in lateral edges thereof which are provisioned for an interface with the sidewalls of a fluid-motion apparatus housing.

Further objects and features of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying figures in which:

FIG. 1 is a partial, longitudinal cross-sectional view in elevation of a compressor, having a diffuser, embodying the teaching ofthe invention;

FIG. 2 is a front elevation view of the diffuser vanes and a portion of the rotor blades, the view taken along section 2-2 of FIG. 1; and

FIG. 3 is a fragmentary, perspective view of a rotor blade and the walled chamber from the inlet end.

As shown in FIGS. 1, 2, and 3 a compressor comprises a housing 12 in which a rotor 14 is rotatively mounted. The rotor 14 has a plurality of blades 16 radially disposed thereon. The blades 16 rotate within an annular, walled chamber 18,

and cooperate with the chamber walls to define, therebetween, substantially separate fluid pressure zones which comprise longitudinally extending fluid passages. The chamber communicates at either ends thereof with a fluid inlet 20 and a outlet 22. A diffuser 24 is disposed within the housing 12 and has a plurality of vanes 26 radially disposed about rotor 14.

Blades 16 are formed with a relieved area 28 in the entrance or inlet end thereof where the blades interface with the wall 30 of the housing 12. The relieved area 28 cooperates with the wall 30 to present a gap 32 between the blade and the wall in chamber 18.

The diffuser 24 also has plurality of gaps formed by the vanes thereof by the provisioning of relieved areas 34 to either sides of each vane 26, again at the entrance or inlet end thereof. Here too, relieved areas 34 cooperate with

wall surfaces

30 and 38 to define gaps 40, at the entrance end of a second, annular, walled chamber 2 defined by walls 36 and 38.

In the embodiments shown in FIGS. 1, 2, and 3, my invention teaches the use of plurality of gaps 40 for each diffuser vane 26 and a single gap 32 for each of the rotor blades 16. However, this is done only by way of example, for it has been shown by experiment that the use of a single gap for each diffuser vane will function substantially as effectively, in accordance with the teaching of my invention; more, a single gap 40 is more easily fabricated.

The purpose of the

gaps

32 and 40 is to equalize the pressure difference across the blades 16 and vanes 26, which is excessive at large angles of attack. It also provides circulation of the fluid from the high-pressure side to the low-pressure side of the blades and vanes which, in turn, energizes the fluid boundary layer. The boundary layer would otherwise tend to build up on the high-pressure side of the vanes 26 and blades 16.

Laboratory tests of a diffuser with these gaps 40, circulating gaps (so-called to denote the facility with which they circulate the disparate fluid pressure to either sides thereof), reduced the flow rate at diffuser stall to 55 percent of the stall flow of the standard diffuser (i.e., a diffuser without circulating gaps). At this lower flow, the pressure rise was 25 percent higher than in a standard diffuser.

Through my disclosure, those skilled in this art will find it possible to practice my invention through other embodiments thereof. For instance, rather than providing

relieved areas

28 and 34 in the lateral edges of the blades 16 and vanes 26, respectively, the circulating

gaps

32 and 40 can be otherwise provisioned. For instance, a portion of wall 30 can be undercut, to define an annular-relieved surface thereat adjacent the entrance ends of blades 16, and the same can be done with respect to walls 36 and 38 at the entrance end of the diffuser 24.

Accordingly, while I have described my invention in connection with specific embodiments thereof it is to be clearly understood that this is done only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof.

Iclaim:

1. A fluid-motion apparatus, such as a fluid compressor, pump, or the like, comprising:

a housing;

a rotor rotatably mounted in said housing;

means for admitting fluid to said housing;

means for discharging fluid from said housing;

first walled chamber means communicating said admitting and discharging means;

said rotor having a plurality of primary elements carried radially thereabout, interposed between said admitting and discharging means, for working engagement thereof with said fluid, said primary elements being cooperative with one wall of said chamber means to define, therebetween, substantially separate, longitudinally extending fluid passages;

said primary elements each further defining given high-pressure and low-pressure fluid zones to either sides thereof;

pump, or the like, comprising:

said elements having first outer radial edge surfaces which form an interface with second surfaces of said one wall of said chamber means; and

at least one of said first and second surfaces has a materialremoved area, with surfacing which diverges away from said interface, which defines a recess which opens on both said high-pressure and low-pressure zones effective for communicating said highand low-pressure fluid zones to control the fluid boundary layer which forms on said elements; and wherein said recess is formed at only one given location in said one surface for effecting said communication of said zones intermediate the ends of said passages.

2. A fluid-motion apparatus, such as a fluid compressor,

pump, or the like, comprising:

a housing;

a rotor rotatably mounted in said housing;

means for admitting fluid to said housing;

means for discharging fluid from said housing;

first walled chamber means communicating said admitting and discharging means;

said primary elements each further defining given high-pressure and low-pressure fluid zones to either sides thereof on the rotation thereof;

at least one of said first and second surfaces has a recess formed therein effective for communicating said highand low-pressure fluid zones to control the fluid boundary layer which forms on said elements; and wherein said elements comprise blades,

said blades each having a configuration in general conformity with that of said first chamber, and

said recess comprises a material-relieved area formed in at least one radial edge of said blades, said area having surfacing which diverges away from said one wall of said chamber means and which cooperates with said one wall of said chamber means to define a gap therebetween which opens on both said high-pressure and said lowpressure zones.

3. A fluid-motion apparatus, according to claim 2, wherein:

said blades each have a given length; and

said relieved area extends for a limited distance along said length to define said gap intermediate the ends of said blade.

4. A fluid-motion apparatus, according to claim 2, wherein:

said relieved area extends into the terminal face of said blade which is disposed adjacent to said fluid admitting means.

5. A fluid-motion apparatus, such as a fluid compressor,

a housing;

a rotor rotatably mounted in said housing;

means for admitting fluid to said housing;

means for discharging fluid from said housing;

first walled chambermeans communicating said admitting and discharging means; 1

said rotor having a plurality of primary elements carried radially thereabout, interposed between said admitting and discharging means, for working engagement thereof with said fluid, said primary elements being cooperative with walls of said chamber means to define, therebetween, substantially separate, longitudinally extending fluid passages;

said primary elements each further defining given high-pressure and low-pressure fluid zones to either sides thereof; said elements having first surfaces ad acent to said fluid-admitting means which interface with second surface of said first chamber means; and

at least one of said first and second surfaces has a recess formed therein for communicating said highand lowpressure fluid zones to control the fluid boundary layer which forms on said elements wherein;

said recess is formed at a given location in said one surface for effecting said communication of said zones intermediate the ends of said passages; and further including diffuser means disposed between said rotor and discharging means, in second walled chamber means formed in said housing;

said diffuser means comprising a plurality of secondary elements radially disposed relative to said rotor, for working engagement thereof with said fluid,

said secondary elements each comprises means defining other high-pressure and low-pressure fluid zones to either sides thereof;

said secondary elements having third surfaces adjacent to said fluid-admitting means which interface with fourth surfaces of said second chamber means; and

at least one of said third and fourth surfaces comprise other means for communicating said other highand low-pressure fluid zones to control the fluid boundary layer which forms on said secondary elements.

6. A fluid-motion apparatus, according to claim 5, wherein:

said secondary elements each have a given length, and

said other means comprise means for effecting said communicating of said other zones intermediate said length.

7. A fluid-motion apparatus, according to claim 5, wherein:

said secondary elements comprise vanes,

said vanes each having a configuration in general conformity with that of said second chamber, and

said other means comprises a relieved area formed in at least one lateral edge of said vanes, said vane-edge area cooperating with said one wall of said second chamber to define a gap therebetween.

8. A fluid-motion apparatus, according to claim 7, wherein:

said vanes each have a given length; and

said vane-edge area extends for a given distance along said length to define said gap intermediate the ends of said vane.

9. A fluid-motion apparatus, according to claim 7, wherein:

said vane-edge area extends into the terminal face of said vane which is disposed adjacent to said fluid discharging means.

Claims

1. A fluid-motion apparatus, such as a fluid compressor, pump, or the like, comprising: a housing; a rotor rotatably mounted in said housing; means for admitting fluid to said housing; means for discharging fluid from said housing; first walled chamber means communicating said admitting and discharging means; said rotor having a plurality of primary elements carried radially thereabout, interposed between said admitting and discharging means, for working engagement thereof with said fluid, said primary elements being cooperative with one wall of said chamber means to define, therebetween, substantially separate, longitudinally extending fluid passages; said primary elements each further defining given high-pressure and low-pressure fluid zones to either sides thereof; said elements having first outer radial edge surfaces which form an interface with second surfaces of said one wall of said chamber means; and at least one of said first and second surfaces has a materialremoved area, with surfacing which diverges away from said interface, which defines a recess which opens on both said high-pressure and low-pressure zones effective for communicating said high- and low-pressure fluid zones to control the fluid boundary layer which forms on said elements; and wherein said recess is formed at only one given location in said one surface for effecting said communication of said zones intermediate the ends of said passages.

2. A fluid-motion apparatus, such as a fluid compressor, pump, or the like, comprising: a housing; a rotor rotatably mounted in said housing; means for admitting fluid to said housing; means for discharging fluid from said housing; first walled chamber means communicating said admitting and discharging means; said rotor having a plurality of primary elements carried radially thereabout, interposed between said admitting and discharging means, for working engagement thereof with said fluid, said primary elements being cooperative with one wall of said chamber means to define, therebetween, substantially separate, longitudinally extending fluid passages; said primary elements each further defining given high-pressure and low-pressure fluid zones to either sides thereof on the rotation thereof; said elements having first outer radial edge surfaces which form an interface with second surfaces of said one wall of said chamber means; and at least one of said first and second surfaces has a recess formed therein effective for communicating said high- and low-pressure fluid zones to control the fluid boundary layer which forms on said elements; and wherein said elements comprise blades, said blades each having a configuration in general conformity with that of said first chamber, and said recess comprises a material-relieved area formed in at least one radial edge of said blades, said area having surfacing which diverges away from said one wall of said chamber means and which cooperates with said one wall of said chamber means to define a gap therebetween which opens on both said high-pressure and said low-pressure zones.

3. A fluid-motion apparatus, according to claim 2, wherein: said blades each have a given length; and said relieved area extends for a limited distance along said length to define said gap intermediate the ends of said blade.

4. A fluid-motion apparatus, according to claim 2, wherein: said relieved area extends into the terminal face of said blade which is disposed adjacent to said fluid admitting means.

5. A fluid-motion apparatus, such as a fluid compressor, pump, or the like, comprising: a housing; a rotor rotatably mounted in said housing; means for admitting fluid to said housing; means for discharging fluid from said housing; first walled chamber means communicating said admitting and discharging means; said rotor having a plurality of primary elements carried radially thereabout, interposed between said admitting and discharging means, for working engagement thereof with said fluid, said primary elements being cooperative with walls of said chamber means to define, therebetween, substantially separate, longitudinally extending fluid passages; said primary elements each further defining given high-pressure and low-pressure fluid zones to either sides thereof; said elements having first surfaces adjacent to said fluid-admitting means which interface with second surface of said first chamber means; and at least one of said first and second surfaces has a recess formed therein for communicating said high- and low-pressure fluid zones to control the fluid boundary layer which forms on said elements wherein; said recess is formed at a given location in said one surface for effecting said communication of said zones intermediate the ends of said passages; and further including diffuser means disposed between said rotor and discharging means, in second walled chamber means formed in said housing; said diffuser means comprising a plurality of secondary elements radially disposed relative to said rotor, for working engagement thereof with said fluid, said secondary elements each comprises means defining other high-pressure and low-pressure fluid zones to either sides thereof; said secondary elements having third surfaces adjacent to said fluid-admitting means which interface with fourth surfaces of said second chamber means; and at least one of said third and fourth surfaces comprise other means for communicating said other high- and low-pressure fluid zones to control the fluid boundary layer which forms on said secondary elements.

6. A fluid-motion apparatus, according to claim 5, wherein: said secondary elements each have a given length, and said other means comprise means for effecting said communicating of said other zones intermediate said length.

7. A fluid-motion apparatus, according to claim 5, wherein: said secondary elements comprise vanes, said vanes each having a configuration in general conformity with that of said second chamber, and said other means comprises a relieved area formed in at least one lateral edge of said vanes, said vane-edge area cooperating with said one wall of said second chamber to define a gap therebetween.

8. A fluid-motion apparatus, according to claim 7, wherein: said vanes each have a given length; and said vane-edge area extends for a given distance along said length to define said gap intermediate the ends of said vane.

9. A fluid-motion apparatus, according to claim 7, wherein: said vane-edge area extends into the terminal face of said vane which is disposed adjacent to said fluid discharging means.