Rotary machine having spacers for control of fluid dynamics   

Abstract: A system includes a rotary machine with a fluid flow path extending along an axis of the rotary machine, a plurality of airfoils disposed about the axis, and a plurality of spacers disposed about the axis. Each spacer of the plurality of spacers is disposed circumferentially between adjacent airfoils of the plurality of airfoils to define a circumferential spacing of the airfoils about the axis.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to rotary machines and, more particularly, turbines and compressors susceptible to resonant behavior in a fluid flow.

Turbines and compressors exchange energy between a fluid and a rotor. For example, a turbine generates energy in response to a fluid flow acting on a plurality of blades, whereas a compressor uses energy to drive a plurality of blades to compress a gas. Unfortunately, the rotation of the blades can create wake and bow waves, which can excite other rotating and stationary structures upstream and downstream from the blades. For example, the wake and bow waves may cause vibration, premature wear, and damage of vanes, blades, nozzles, airfoils, rotors, and other structures in the fluid flow.

Certain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below.

In a first embodiment, a system includes a rotary machine with a fluid flow path extending along an axis of the rotary machine, a plurality of airfoils disposed about the axis, and a plurality of spacers disposed about the axis. Each spacer of the plurality of spacers may be disposed circumferentially between adjacent airfoils of the plurality of airfoils to define a circumferential spacing of the airfoils about the axis.

In a second embodiment, a system includes a rotary machine with a fluid flow path and a plurality of segments disposed in an annular arrangement along the fluid flow path. The plurality of segments include spacer segments and flow control segments. The flow control segments protrude into the fluid flow path. Each spacer segment is disposed circumferentially between adjacent flow control segments to define a circumferential spacing of the flow control segments.

In a third embodiment, a method includes mounting a plurality of airfoil segments in a rotary machine along a fluid flow path, and spacing the plurality of airfoil segments in a circumferential spacing with a plurality of spacer segments.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 is a sectional view of an embodiment of a gas turbine engine sectioned through a longitudinal axis;

FIG. 2 is a front view of an embodiment of a rotor with a non-uniform spacing of blades;

FIG. 3 is a front view of an embodiment of a rotor with a non-uniform spacing of blades;

FIG. 4 is a front view of an embodiment of a rotor with a non-uniform spacing of blades;

FIG. 5 is a perspective view of an embodiment of three rotors, wherein each rotor has a different non-uniform spacing of blades;

FIG. 6 is a partial front view of an embodiment of a rotor with differently sized spacers between blades;

FIG. 7 is a top view of an embodiment of a rotor with differently sized spacers between blades;

FIG. 8 is a top view of an embodiment of a rotor with differently sized spacers between blades;

FIG. 9 is a front view of an embodiment of a blade having a T-shaped geometry;

FIG. 10 is a partial front view of an embodiment of a rotor with blades having differently sized bases;

FIG. 11 is a top view of an embodiment of a rotor with blades having differently sized bases;

FIG. 12 is a top view of an embodiment of a rotor with blades having differently sized bases;

FIG. 13 is a partial front view of an embodiment of a stator with differently sized spacers between vanes;

FIG. 14 is a partial front view of an embodiment of a stator with vanes having differently sized bases;

FIG. 15 is a partial front view of an embodiment of a rotor with uniform large spacers between blades;

FIG. 16 is a partial front view of an embodiment of a rotor with uniform medium spacers between blades;

FIG. 17 is a partial front view of an embodiment of a rotor with uniform small spacers between blades;

FIG. 18 is a graph illustrating resonant frequency of stators and rotors with differently sized spacers with respect to the rotational speed of the engine;

FIG. 19 is a partial front view of an embodiment of a stator with uniform large sized spacers between vanes;

FIG. 20 is a partial front view of an embodiment of a stator with uniform medium spacers between vanes; and

FIG. 21 is a partial front view of an embodiment of a stator with uniform small spacers between vanes.

DETAILED DESCRIPTION

One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers\' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

The disclosed embodiments are directed toward tuning of fluid dynamics in rotary machines, such as a turbine or a compressor, via an adjustment of the spacing between rotating blades or stationary vanes and/or an adjustment of the count of rotating blades or stationary vanes. In particular, the disclosed embodiments adjust the spacing and/or count of blades or vanes to control the frequency of wake and bow waves formed by the rotating blades, stationary vanes, or other structures in the fluid flow. For example, a non-uniform spacing or modified count of rotating blades or stationary vanes may reduce the possibility of resonant behavior, vibration, and undesirable fluid dynamics in the turbine or compressor. In other words, the non-uniform spacing or modified count of rotating blades or stationary vanes may reduce or eliminate the ability of the wake and bow waves to cause resonance in structures along the fluid flow path. Instead, the non-uniform spacing or modified count of rotating blades or stationary vanes may dampen and reduce the response of structures in the fluid flow path by changing the frequency of the wake and bow waves. The non-uniform spacing or modified count may be achieved with spacers, modified mounting structures, mounting adapters, modified stators, modified rotors, or some combination thereof.

For example, the non-uniform spacing of the blades or vanes may be achieved with differently sized spacers between adjacent blades or vanes, differently sized bases of adjacent blades or vanes, or any combination thereof. The non-uniform spacing of the blades or vanes may include both non-uniform spacing of the blades about a circumference of a particular stage (e.g., turbine or compressor stage), non-uniform spacing of the blades from one stage to another, or a combination thereof. The non-uniform spacing effectively reduces and dampens the wake and bow waves generated by the rotating blades, thereby reducing the possibility of vibration, premature wear, and damage caused by such wake and bow waves on stationary and rotating structures.

By further example, the modified count of blades or vanes may be achieved by uniformly spacing a greater or smaller count of blades or vanes via spacers, modified mounting bases, or a combination thereof. In certain embodiments employing spacers, a first set of spacers (e.g., large spacers) may be used to provide a first uniform spacing of blades or vanes, a second set of spacers (e.g., medium spacers) may be used to provide a second uniform spacing of blades or vanes, a third set of spacers (e.g., small spacers) may be used to provide a third uniform spacing of blades or vanes, and so forth. Similarly, in certain embodiments employing modified bases, a first set of blades or vanes with a first mounting base size (e.g., large mounting base) may be used to provide a first uniform spacing of blades or vanes, a second set of blades or vanes with a second mounting base size (e.g., medium mounting base) may be used to provide a second uniform spacing of blades or vanes, a third set of blades or vanes with a third mounting base size (e.g., small mounting base) may be used to provide a third uniform spacing of blades or vanes, and so forth. In each embodiment, the blade or vane count may be increased or decreased to change the frequency of wake and bow waves at specific rotational speeds of the rotary machine. Thus, the modified count is configured to change the frequency of the wake and bow waves to avoid the resonant frequency of the structures in the fluid flow path at specific rotational speeds.

The disclosed embodiments of non-uniform spacing or modified count of rotating blades or stationary vanes may be utilized in any suitable rotary machine, such as turbines, compressors, and rotary pumps. However, for purposes of discussion, the disclosed embodiments are presented in context of a gas turbine engine. FIG. 1 is a cross-sectional side view of an embodiment of a gas turbine engine 150. As described further below, a non-uniform spacing or modified count of rotating blades or stationary vanes may be employed within the gas turbine engine 150 to reduce and/or dampen periodic oscillations, vibration, and/or harmonic behavior of wake and bow waves in the fluid flow. For example, a non-uniform spacing or modified count of rotating blades or stationary vanes may be used in a compressor 152 and a turbine 154 of the gas turbine engine 150. Furthermore, the non-uniform spacing or modified count of rotating blades or stationary vanes may be used in a single stage or multiple stages of the compressor 152 and the turbine 154, and may vary from one stage to another.

In the illustrated embodiment, the gas turbine engine 150 includes an air intake section 156, the compressor 152, one or more combustors 158, the turbine 154, and an exhaust section 160. The compressor 152 includes a plurality of compressor stages 162 (e.g., 1 to 20 stages), each having a plurality of rotating compressor blades 164 and stationary compressor vanes 166. The compressor 152 is configured to intake air from the air intake section 156 and progressively increase the air pressure in the stages 162. Eventually, the gas turbine engine 150 directs the compressed air from the compressor 152 to the one or more combustors 158. Each combustor 158 is configured to mix the compressed air with fuel, combust the fuel air mixture, and direct hot combustion gases toward the turbine 154. Accordingly, each combustor 158 includes one or more fuel nozzles 168 and a transition piece 170 leading toward the turbine 154. The turbine 154 includes a plurality of turbine stages 172 (e.g., 1 to 20 stages), such as stages 174, 176, and 178, each having a plurality of rotating turbine blades 180 and stationary nozzle assemblies or turbine vanes 182. In turn, the turbine blades 180 are coupled to respective turbine wheels 184, which are coupled to a rotating shaft 186. The turbine 154 is configured to intake the hot combustion gases from the combustors 158, and progressively extract energy from the hot combustion gases to drive the blades 180 in the turbine stages 172. As the hot combustion gases cause rotation of the turbine blades 180, the shaft 186 rotates to drive the compressor 152 and any other suitable load, such as an electrical generator. Eventually, the gas turbine engine 150 diffuses and exhausts the combustion gases through the exhaust section 160.

As discussed in detail below, a variety of embodiments of non-uniform spacing or modified count of rotating blades or stationary vanes may be used in the compressor 152 and the turbine 154 to tune the fluid dynamics in a manner that reduces undesirable behavior, such as resonance and vibration. For example, as discussed with reference to FIGS. 2-14, a non-uniform spacing of the compressor blades 164, the compressor vanes 166, the turbine blades 180, and/or the turbine vanes 182 may be selected to reduce, dampen, or frequency shift the wake and bow waves created in the gas turbine engine 150. Similarly, as discussed with reference to FIGS. 15-21, a modified count (e.g., modified uniform spacing) of the compressor blades 164, the compressor vanes 166, the turbine blades 180, and/or the turbine vanes 182 may be selected to reduce, dampen, or frequency shift the wake and bow waves created in the gas turbine engine 150. In these various embodiments, the non-uniform spacing or modified count of rotating blades or stationary vanes is specifically selected to reduce the possibility of resonance and vibration, thereby improving the performance and increasing the longevity of the gas turbine engine 150.

FIG. 2 is a front view of an embodiment of a rotor 200 with non-uniformly spaced blades. In certain embodiments, the rotor 200 may be disposed in a turbine, a compressor, or another rotary machine. For example, the rotor 200 may be disposed in a gas turbine, a steam turbine, a water turbine, or any combination thereof. Furthermore, the rotor 200 may be used in multiple stages of a rotary machine, each have the same or different arrangement of the non-uniformly spaced blades.

The illustrated rotor 200 has non-uniformly spaced blades 208, which may be described by dividing the rotor 200 into two equal sections 202 and 204 (e.g., 180 degrees each) via an intermediate line 206. In certain embodiments, each section 202 and 204 may have a different number of blades 208, thereby creating non-uniform blade spacing. For example, the illustrated upper section 202 has three blades 208, while the illustrated lower section 204 has six blades 208. Thus, the upper section 202 has half as many blades 208 as the lower section 204. In other embodiments, the upper and lower sections 202 and 204 may differ in the number of blades 208 by approximately 1 to 1.005, 1 to 1.01, 1 to 1.02, 1 to 1.05, or 1 to 3. For example, the percentage of blades 208 of the upper section 202 relative to the lower section 204 may range between approximately 50 to 99.99 percent, 75 to 99.99 percent, 95 to 99.99, or 97-99.99 percent. However, any difference in the number of blades 208 between the upper and lower sections 202 and 204 may be employed to reduce and dampen wake and bow waves associated with rotation of the blades 208 on stationary airfoils or structures.

In addition, the blades 208 may be evenly or unevenly spaced within each section 202 and 204. For example, in the illustrated embodiment, the blades 208 in the upper section 202 are evenly spaced from one another by a first circumferential spacing 210 (e.g., arc lengths), while the blades 208 in the lower section 204 are evenly spaced from one another by a second circumferential spacing 212 (e.g., arc lengths). Although each section 202 and 204 has equal spacing, the circumferential spacing 210 is different from the circumferential spacing 212. In other embodiments, the circumferential spacing 210 may vary from one blade 208 to another in the upper section 202 and/or the circumferential spacing 212 may vary from one blade 208 to another in the lower section 204. In each of these embodiments, the non-uniform blade spacing is configured to reduce the possibility of resonance on stationary airfoils and structures due to periodic generation of wake and bow waves by rotating airfoils or structures. The non-uniform blade spacing may effectively dampen and reduce the wake and bow waves due to their non-periodic generation by the non-uniform rotating airfoils or structures. In this manner, the non-uniform blade spacing is able to lessen the impact of wake and bow waves on various downstream components, e.g., vanes, nozzles, stators, airfoils, etc.

FIG. 3 is a front view of an embodiment of a rotor 220 with non-uniformly spaced blades. In certain embodiments, the rotor 220 may be disposed in a turbine, a compressor, or another rotary machine. For example, the rotor 220 may be disposed in a gas turbine, a steam turbine, a water turbine, or any combination thereof. Furthermore, the rotor 220 may be used in multiple stages of a rotary machine, each have the same or different arrangement of the non-uniformly spaced blades.

The illustrated rotor 220 has non-uniformly spaced blades 234, which may be described by dividing the rotor 220 into four equal sections 222, 224, 226, and 228 (e.g., 90 degrees each) via intermediate lines 230 and 232. In certain embodiments, at least one or more of the sections 222, 224, 226, and 228 may have a different number of blades 234 relative to the other sections, thereby creating non-uniform blade spacing. For example, the sections 222, 224, 226, and 228 may have 1, 2, 3, or 4 different numbers of blades 234 in the respective sections. In the illustrated embodiment, each section 222, 224, 226, and 228 has a different number of blades 234. Section 222 has 3 blades equally spaced from one another by a circumferential distance 236, section 224 has 6 blades equally spaced from one another by a circumferential distance 238, section 226 has 2 blades equally spaced from one another by a circumferential distance 240, and section 228 has 5 blades equally spaced from one another by a circumferential distance 242. In this embodiment, sections 224 and 226 have an even yet different number of blades 234, while sections 222 and 228 have an odd yet different number of blades 234. In other embodiments, the sections 222, 224, 226, and 228 may have any configuration of even and odd numbers of blades 234, provided that at least one section has a different number of blades 234 relative to the remaining sections. For example, the sections 222, 224, 226, and 228 may vary in the number of blades 234 with respect to each other by approximately 1 to 1.005, 1 to 1.01, 1 to 1.02, 1 to 1.05, or 1 to 3.

In addition, the blades 234 may be evenly or unevenly spaced within each section 222, 224, 226, and 228. For example, in the illustrated embodiment, the blades 234 in the section 222 are evenly spaced from one another by the first circumferential spacing 236 (e.g., arc lengths), the blades 234 in the section 224 are evenly spaced from one another by the second circumferential spacing 238 (e.g., arc lengths), the blades 234 in the section 226 are evenly spaced from one another by the third circumferential spacing 240 (e.g., arc lengths), and the blades 234 in the section 228 are evenly spaced from one another by the fourth circumferential spacing 242 (e.g., arc lengths). Although each section 222, 224, 226, and 228 has equal spacing, the circumferential spacing 236, 238, 240, and 242 varies from one section to another. In other embodiments, the circumferential spacing may vary within each individual section. In each of these embodiments, the non-uniform blade spacing is configured to reduce the possibility of resonance due to periodic generation of wake and bow waves. Furthermore, the non-uniform blade spacing may effectively dampen and reduce the response of stationary airfoils or structures by the rotating airfoils or structure\'s wake and bow waves due to their non-periodic generation by the blades 234. In this manner, the non-uniform blade spacing is able to lessen the impact of wake and bow waves on various downstream components, e.g., vanes, nozzles, stators, airfoils, etc.

FIG. 4 is a front view of an embodiment of a rotor 250 with non-uniformly spaced blades. In certain embodiments, the rotor 250 may be disposed in a turbine, a compressor, or another rotary machine. For example, the rotor 250 may be disposed in a gas turbine, a steam turbine, a water turbine, or any combination thereof. Furthermore, the rotor 250 may be used in multiple stages of a rotary machine, each have the same or different arrangement of the non-uniformly spaced blades.

The illustrated rotor 250 has non-uniformly spaced blades 264, which may be described by dividing the rotor 250 into three equal sections 252, 254, and 256 (e.g., 120 degrees each) via intermediate lines 258, 260, and 262. In certain embodiments, at least one or more of the sections 252, 254, and 256 may have a different number of blades 264 relative to the other sections, thereby creating non-uniform blade spacing. For example, the sections 252, 254, and 256 may have 2 or 3 different numbers of blades 264 in the respective sections. In the illustrated embodiment, each section 252, 254, and 256 has a different number of blades 264. Section 252 has 3 blades equally spaced from one another by a circumferential distance 266, section 254 has 6 blades equally spaced from one another by a circumferential distance 268, and section 256 has 5 blades equally spaced from one another by a circumferential distance 270. In this embodiment, sections 252 and 256 have an odd yet different number of blades 264, while section 254 has an even number of blades 264. In other embodiments, the sections 252, 254, and 256 may have any configuration of even and odd numbers of blades 264, provided that at least one section has a different number of blades 264 relative to the remaining sections. For example, the sections 252, 254, and 256 may vary in the number of blades 264 with respect to each other by approximately 1 to 1.005, 1 to 1.01, 1 to 1.02, 1 to 1.05, or 1 to 3.

In addition, the blades 264 may be evenly or unevenly spaced within each section 252, 254, and 256. For example, in the illustrated embodiment, the blades 264 in the section 252 are evenly spaced from one another by the first circumferential spacing 266 (e.g., arc lengths), the blades 264 in the section 254 are evenly spaced from one another by the second circumferential spacing 268 (e.g., arc lengths), and the blades 264 in the section 256 are evenly spaced from one another by the third circumferential spacing 270 (e.g., arc lengths). Although each section 252, 254, and 256 has equal spacing, the circumferential spacing 266, 268, and 270 varies from one section to another. In other embodiments, the circumferential spacing may vary within each individual section. In each of these embodiments, the non-uniform blade spacing is configured to reduce the possibility of resonance due to periodic generation of wake and bow waves. Furthermore, the non-uniform blade spacing may effectively dampen and reduce the response of stationary airfoils or structures by the rotating airfoils or structure\'s wake and bow waves due to their non-periodic generation by the blades 264. In this manner, the non-uniform blade spacing is able to lessen the impact of wake and bow waves on various downstream components, e.g., vanes, nozzles, stators, airfoils, etc.

FIG. 5 is a perspective view of an embodiment of three rotors 280, 282, and 284, wherein each rotor has a different non-uniform spacing of blades 286. For example, the illustrated rotors 280, 282, and 284 may correspond to three stages of the compressor 152 or the turbine 154 as illustrated in FIG. 1. As illustrated, each of the rotors 280, 282, and 284 has non-uniform spacing of blades 286 between respective upper sections 288, 290, and 292 and respective lower sections 294, 296, and 298. For example, the rotor 280 includes three blades 286 in the upper section 288 and five blades 286 in the lower section 294, the rotor 282 includes four blades 286 in the upper section 290 and six blades 286 in the lower section 296, and the rotor 284 includes five blades 286 in the upper section 292 and seven blades 286 in the lower section 298. Thus, the upper sections 280, 282, and 284 have a greater number of blades 286 relative to the lower sections 294, 296, and 298 in each respective rotor 280, 282, and 284. In the illustrated embodiment, the number of blades 286 increases by one blade 286 from one upper section to another, while also increasing by one blade 286 from one lower section to another. In other embodiments, the upper and lower sections may differ in the number of blades 286 by approximately 1 to 1.005, 1 to 1.01, 1 to 1.02, 1 to 1.05, or 1 to 3 within each individual rotor and/or from one rotor to another. In addition, the blades 286 may be evenly or unevenly spaced within each section 288, 290, 292, 294, 296, and 298.

In each of these embodiments, the non-uniform blade spacing is configured to reduce the possibility of resonance due to periodic generation of wake and bow waves. Furthermore, the non-uniform blade spacing may effectively dampen and reduce the response of stationary airfoils or structures by the rotating airfoils or structure\'s wake and bow waves due to their non-periodic generation by the blades 286. In this manner, the non-uniform blade spacing is able to lessen the impact of wake and bow waves on various downstream components, e.g., vanes, nozzles, stators, airfoils, etc. In the embodiment of FIG. 5, the non-uniform blade spacing is provided both within each individual rotor 280, 282, and 284, and also from one rotor to another (e.g., one stage to another). Thus, the non-uniformity from one rotor to another may further reduce the possibility of resonance caused by periodic generation of wake and bow waves in a rotary machine.

FIG. 6 is a section of a front view of an embodiment of a rotor 310 with differently sized spacers 312 between bases 314 of blades 316. In particular, the differently sized spacers 312 enable implementation of a variety of non-uniform blade spacing configurations with equally sized bases 314 and/or blades 316, thereby reducing manufacturing costs of the blades 316. Although any number and size of spacers 312 may be used to provide the non-uniform blade spacing, the illustrated embodiment includes three differently sized spacers 312 for purposes of discussion. The illustrated spacers 312 include a small spacer labeled as “S”, a medium spacer labeled as “M”, and a large spacer labeled as “L.” The size of the spacers 312 may vary in a circumferential direction, as indicated by dimension 318 for the small spacer, dimension 320 for the medium spacer, and dimension 322 for the large spacer. In certain embodiments, a plurality of spacers 312 may be disposed between adjacent bases 314, wherein the spacers 312 are either of equal or different sizes. In other words, the differently sized spacers 312 may be either a one-piece construction or a multi-piece construction using a plurality of smaller spacers to generate a greater spacing. In either embodiment, the dimensions 318, 320, and 322 may progressively increase by a percentage of approximately 1 to 1000 percent, 5 to 500 percent, or 10 to 100 percent. In other embodiments, the rotor 310 may include more or fewer differently sized spacers 312, e.g., 2 to 100, 2 to 50, 2 to 25, or 2 to 10. The differently sized spacers 312 (e.g., S, M, and L) also may be arranged in a variety of repeating patterns, or they may be arranged in a random order.

FIG. 7 is a top view of an embodiment of a rotor 322 with differently sized spacers 324 between bases 326 of blades 328. Similar to the embodiment of FIG. 6, the differently sized spacers 324 enable implementation of a variety of non-uniform blade spacing configurations with equally sized bases 326 and/or blades 328, thereby reducing manufacturing costs of the blades 328. Although any number and size of spacers 324 may be used to provide the non-uniform blade spacing, the illustrated embodiment includes three differently sized spacers 324 for purposes of discussion. The illustrated spacers 324 include a small spacer labeled as “S”, a medium spacer labeled as “M”, and a large spacer labeled as “L.” The size of the spacers 324 may vary in a circumferential direction, as discussed above with reference to FIG. 5. The differently sized spacers 324 (e.g., S, M, and L) also may be arranged in a variety of repeating patterns, or they may be arranged in a random order.

In the illustrated embodiment, the spacers 324 interface with the bases 326 of the blades 328 at an angled interface 330. For example, the angled interface 330 is oriented at an angle 332 relative to a rotational axis of the rotor 322, as indicated by line 334. The angle 332 may range between approximately 0 to 60 degrees, 5 to 45 degrees, or 10 to 30 degrees. The illustrated angled interface 330 is a straight edge or flat surface. However, other embodiments of the interface 330 may have non-straight geometries.

FIG. 8 is a top view of an embodiment of a rotor 340 with differently sized spacers 342 between bases 344 of blades 346. Similar to the embodiment of FIGS. 6 and 8, the differently sized spacers 342 enable implementation of a variety of non-uniform blade spacing configurations with equally sized bases 344 and/or blades 346, thereby reducing manufacturing costs of the blades 346. Although any number and size of spacers 342 may be used to provide the non-uniform blade spacing, the illustrated embodiment includes three differently sized spacers 342 for purposes of discussion. The illustrated spacers 342 include a small spacer labeled as “S”, a medium spacer labeled as “M”, and a large spacer labeled as “L.” The size of the spacers 342 may vary in a circumferential direction, as discussed above with reference to FIG. 6. The differently sized spacers 342 (e.g., S, M, and L) also may be arranged in a variety of repeating patterns, or they may be arranged in a random order.

In the illustrated embodiment, the spacers 342 interface with the bases 344 of the blades 346 at a non-straight interface 350. For example, the interface 350 may include a first curved portion 352 and a second curved portion 354, which may be the same or different from one another. However, the interface 350 also may have other non-straight geometries, such as multiple straight segments of different angles, one or more protrusions, one or more recesses, or a combination thereof. As illustrated, the first and second curved portions 352 and 354 curve in opposite directions from one another. However, the curved portions 352 and 354 may define any other curved geometry.

FIG. 9 is a front view of an embodiment of a blade 360 having a T-shaped geometry 361, which may be arranged in a non-uniform blade spacing in accordance with the disclosed embodiments. The illustrated blade 360 includes a base portion 362 and a blade portion 364, which may be integral with one another (e.g., one-piece). The base portion 362 includes a first flange 366, a second flange 368 offset from the first flange 366, a neck 370 extending between the flanges 366 and 368, and opposite slots 372 and 374 disposed between the flanges 366 and 368. During assembly, the flanges 366 and 368 and slots 372 and 374 are configured to interlock with a circumferential rail structure about the rotor. In other words, the flanges 366 and 368 and slots 372 and 374 are configured to slide circumferentially into place along the rotor, thereby securing the blade 360 in the axial and radial directions. In the embodiments of FIGS. 6-8, these blades 360 may be spaced apart in the circumferential direction by a plurality of differently sized spacers having a similar base portion, thereby providing a non-uniform blade spacing of the blades 360.

FIG. 10 is a section of a front view of an embodiment of a rotor 384 with differently sized bases 386 of blades 388. In particular, the differently sized bases 386 enable implementation of a variety of non-uniform blade spacing configurations with or without spacers. If spacers are used with the differently sized bases 386, the spacers may be equally sized or differently sized to provide more flexibility in the non-uniform blade spacing. Although any number of differently sized bases 386 may be used to provide the non-uniform blade spacing, the illustrated embodiment includes three differently sized bases 386 for purposes of discussion. The illustrated bases 386 include a small base labeled as “S”, a medium base labeled as “M”, and a large base labeled as “L.” The size of the bases 386 may vary in a circumferential direction, as indicated by dimension 390 for the small base, dimension 392 for the medium base, and dimension 394 for the large base. For example, these dimensions 390, 392, and 394 may progressively increase by a percentage of approximately 1 to 1000 percent, 5 to 500 percent, or 10 to 100 percent. In other embodiments, the rotor 384 may include more of fewer differently sized bases 386, e.g., 2 to 100, 2 to 50, 2 to 25, or 2 to 10. The differently sized bases 386 (e.g., S, M, and L) also may be arranged in a variety of repeating patterns, or they may be arranged in a random order.

FIG. 11 is a top view of an embodiment of a rotor 400 with differently sized blade bases 402 supporting blades 404. Similar to the embodiment of FIG. 10, the differently sized bases 402 enable implementation of a variety of non-uniform blade spacing configurations with or without spacers. Although any number and size of bases 402 may be used to provide the non-uniform blade spacing, the illustrated embodiment includes three differently sized bases 402 for purposes of discussion. The illustrated bases 402 include a small base labeled as “S”, a medium base labeled as “M”, and a large base labeled as “L.” The size of the bases 402 may vary in a circumferential direction, as discussed above with reference to FIG. 10. The differently sized bases 402 (e.g., S, M, and L) also may be arranged in a variety of repeating patterns, or they may be arranged in a random order.

In the illustrated embodiment, the bases 402 interface with one another at an angled interface 406. For example, the angled interface 406 is oriented at an angle 408 relative to a rotational axis of the rotor 400, as indicated by line 409. The angle 408 may range between approximately 0 to 60 degrees, 5 to 45 degrees, or 10 to 30 degrees. The illustrated angled interface 406 is a straight edge or flat surface. However, other embodiments of the interface 406 may have non-straight geometries.

FIG. 12 is a top view of an embodiment of a rotor 410 with differently sized blade bases 412 supporting blades 414. Similar to the embodiment of FIGS. 10 and 12, the differently sized bases 412 enable implementation of a variety of non-uniform blade spacing configurations with or without spacers. Although any number and size of bases 412 may be used to provide the non-uniform blade spacing, the illustrated embodiment includes three differently sized bases 412 for purposes of discussion. The illustrated bases 412 include a small base labeled as “S”, a medium base labeled as “M”, and a large base labeled as “L.” The size of the bases 412 may vary in a circumferential direction, as discussed above with reference to FIG. 10. The differently sized bases 412 (e.g., S, M, and L) also may be arranged in a variety of repeating patterns, or they may be arranged in a random order.

In the illustrated embodiment, the bases 412 interface with one another at a non-straight interface 416. For example, the interface 416 may include a first curved portion 418 and a second curved portion 420, which may be the same or different from one another. However, the interface 416 also may have other non-straight geometries, such as multiple straight segments of different angles, one or more protrusions, one or more recesses, or a combination thereof. As illustrated, the first and second curved portions 418 and 420 curve in opposite directions from one another. However, the curved portions 418 and 420 may define any other curved geometry.

FIG. 13 is a section of a front view of an embodiment of a stator 440 with differently sized spacers 442 between bases 444 of vanes 446. In particular, the differently sized spacers 442 enable implementation of a variety of non-uniform vane spacing configurations with equally sized bases 444 and/or vanes 446, thereby reducing manufacturing costs of the vanes 446. Although any number and size of spacers 442 may be used to provide the non-uniform vane spacing, the illustrated embodiment includes three differently sized spacers 442 for purposes of discussion. The illustrated spacers 442 include a small spacer labeled as “S”, a medium spacer labeled as “M”, and a large spacer labeled as “L.” The size of the spacers 442 may vary in a circumferential direction, as indicated by dimension 448 for the small spacer, dimension 450 for the medium spacer, and dimension 452 for the large spacer. In certain embodiments, a plurality of spacers 442 may be disposed between adjacent bases 444, wherein the spacers 442 are either of equal or different sizes. In other words, the differently sized spacers 442 may be either a one-piece construction or a multi-piece construction using a plurality of smaller spacers to generate a greater spacing. In either embodiment, the dimensions 448, 450, and 452 may progressively increase by a percentage of approximately 1 to 1000 percent, 5 to 500 percent, or 10 to 100 percent. In other embodiments, the stator 440 may include more or fewer differently sized spacers 442, e.g., 2 to 100, 2 to 50, 2 to 25, or 2 to 10. The differently sized spacers 442 (e.g., S, M, and L) also may be arranged in a variety of repeating patterns, or they may be arranged in a random order.

FIG. 14 is a section of a front view of an embodiment of a stator 460 with differently sized bases 462 of vanes 464. In particular, the differently sized bases 462 enable implementation of a variety of non-uniform vane spacing configurations with or without spacers. If spacers are used with the differently sized bases 462, the spacers may be equally sized or differently sized to provide more flexibility in the non-uniform vane spacing. Although any number of differently sized bases 462 may be used to provide the non-uniform vane spacing, the illustrated embodiment includes three differently sized bases 462 for purposes of discussion. The illustrated bases 462 include a small base labeled as “S”, a medium base labeled as “M”, and a large base labeled as “L.” The size of the bases 462 may vary in a circumferential direction, as indicated by dimension 466 for the small base, dimension 468 for the medium base, and dimension 470 for the large base. For example, these dimensions 466, 468, and 470 may progressively increase by a percentage of approximately 1 to 1000 percent, 5 to 500 percent, or 10 to 100 percent. In other embodiments, the stator 460 may include more of fewer differently sized bases 462, e.g., 2 to 100, 2 to 50, 2 to 25, or 2 to 10. The differently sized bases 462 (e.g., S, M, and L) also may be arranged in a variety of repeating patterns, or they may be arranged in a random order.

As discussed above, the present embodiments may tune the fluid dynamics in a rotary machine, such as a compressor or turbine, via an adjustment of the spacing between rotating blades or stationary vanes and/or an adjustment of the count of rotating blades or stationary vanes. This tuning may substantially reduce or eliminate the possibility of resonance behavior in the rotary machine, e.g., resonant behavior due to wakes and bow waves. The embodiments of FIGS. 2-14 provide a non-uniform spacing of rotating blades or stationary vanes, which may also correspond with a change or no change in the count of the blades or vanes. The embodiments of FIGS. 15-21 specifically modify the count of the blades or vanes, while maintaining a uniform spacing of the blades or vanes. As discussed in further detail below, changing the number of blades or vanes on respective rotors and stators while maintaining uniform spacing changes the frequency of wake and bow waves at specific rotational speeds. For instance, altering the size of the spacers may increase or decrease the blade count by any suitable number, e.g., 1 to 5, 1 to 10, or 1 to 20. This frequency change may prevent a long-lasting resonant response in structures along the flow path (e.g., rotors, stators, etc.) at specific rotational speeds.

FIGS. 15, 16, and 17 illustrate the use of three differently sized spacers to provide a different uniform blade spacing and blade count, which may be selectively used to vary the frequency of wakes and bow waves in a rotary machine such as a turbine or a compressor. Although FIGS. 15, 16, and 17 illustrate only three sizes of spacers (i.e., large, medium, and small), certain embodiments may employ any number of spacer sizes (e.g., 2 to 100 different sizes) to modify the blade spacing and count. FIG. 15 is a section of a front view of an embodiment of a rotor 480 with large spacers 482 between blade bases 484 supporting blades 486. In the illustrated embodiment, the large spacers 482 have an equal size to separate adjacent blade bases 484 by an equal distance 488 around the rotor 480. The large spacers 482 also separate the blades 486 by an equal distance 490 around the rotor 480. Relative to the small and medium spacers as illustrated in FIGS. 16 and 17, the large spacers 482 decrease the number of blades 486 on the rotor 480, thereby decreasing the frequency of the bow and wake waves. The large spacers 482 may be used to shift the frequency of the bow and wake waves away from a resonant frequency, e.g., if the medium or small spacers result in a frequency too close to the resonant frequency.

FIG. 16 is a section of a front view of an embodiment of a rotor 500 with medium spacers 502 between blade bases 504 supporting blades 506. In the illustrated embodiment, the medium spacers 502 have an equal size to separate adjacent blade bases 504 by an equal distance 508 around the rotor 500. The medium spacers 502 also separate the blades 506 by an equal distance 510 around the rotor 500. Relative to the large spacers as illustrated in FIG. 15, the medium spacers 502 increase the number of blades 506 on the rotor 500, thereby increasing the frequency of the bow and wake waves. Relative to the small spacers as illustrated in FIG. 17, the medium spacers 502 decrease the number of blades 506 on the rotor 500, thereby decreasing the frequency of the bow and wake waves. The medium spacers 502 may be used to shift the frequency of the bow and wake waves away from a resonant frequency, e.g., if the large or small spacers result in a frequency too close to the resonant frequency.

FIG. 17 is a section of a front view of an embodiment of a rotor 520 with small spacers 522 between blade bases 524 supporting blades 526. In the illustrated embodiment, the small spacers 522 have an equal size to separate adjacent blade bases 524 by an equal distance 528 around the rotor 520. The small spacers 522 also separate the blades 526 by an equal distance 530 around the rotor 520. Relative to the large and medium spacers as illustrated in FIGS. 15 and 16, the small spacers 522 increase the number of blades 526 on the rotor 520, thereby increasing the frequency of the bow and wake waves. The small spacers 522 may be used to shift the frequency of the bow and wake waves away from a resonant frequency, e.g., if the large and medium spacers result in a frequency too close to the resonant frequency.

FIG. 18 is a graph 530 illustrating a fluid oscillation frequency or vibration frequency versus rotational speed of a rotary machine, such as a turbine or a compressor. As illustrated in FIG. 18, the x-axis 532 represents the rotational speed of the rotary machine, while the y-axis 534 represents the fluid oscillation frequency or vibration frequency of a structure in the fluid flow. The dashed vertical line 536 represents a normal rotational speed of the rotary machine, e.g., a design speed of a turbine engine. A curve 538 represents a resonant frequency of a structure in the fluid flow. For example, the curve 538 may correspond to a resonant frequency of vibration of a stationary structure (e.g., vane) upstream or downstream from a rotating blade that produces wake and bow waves. Lines 540, 542, and 544 represent the frequency of oscillations of the fluid flow (e.g., wake or bow waves) driven by rotation of the blades, wherein each line 540, 542, and 544 represents a different count of equally spaced blades. In particular, the line 540 represents a large count of blades provided by a plurality of small spacers as represented by “S,” the line 542 represents a medium count of blades provided by a plurality of medium spacers as represented by “M,” and the line 544 represents a small count of blades provided by a plurality of large spacers as represented by “L.” Accordingly, the line 540 may correspond to the embodiment of FIG. 17, the line 542 may correspond to the embodiment of FIG. 16, and the line 544 may correspond to the embodiment of FIG. 15.

As illustrated in FIG. 18, an increase in the blade count corresponding to a decrease in the spacer size causes an increase in the frequency of oscillations (e.g., wake or bow waves) generated by the blades, whereas a decrease in the blade count corresponding to a increase in the spacer size causes an decrease in the frequency of oscillations (e.g., wake or bow waves) generated by the blades. Thus, the disclosed embodiments adjust the spacer size to alter the blade count, and thus alter the frequency of oscillations, to avoid the resonant frequency for a particular rotational speed. The intersections of the lines 540, 542, and 544 with the line 538 represent resonant points 546, 548, and 550 for the different blade counts. For example, the resonant point 546 represents a first resonant frequency 552 at a first rotational speed 554, wherein the frequency of oscillations (e.g., wake or bow waves) generated by rotation of the blades 526 of FIG. 17 (i.e., small spacers; large blade count) intersects with the resonant frequency of the structure (e.g., vane) upstream or downstream from the blades 526. By further example, the resonant point 548 represents a second resonant frequency 556 at a second rotational speed 558, wherein the frequency of oscillations (e.g., wake or bow waves) generated by rotation of the blades 506 of FIG. 16 (i.e., medium spacers; medium blade count) intersects with the resonant frequency of the structure (e.g., vane) upstream or downstream from the blades 506. By further example, the resonant point 550 represents a third resonant frequency 560 at a third rotational speed 562, wherein the frequency of oscillations (e.g., wake or bow waves) generated by rotation of the blades 486 of FIG. 15 (i.e., large spacers; small blade count) intersects with the resonant frequency of the structure (e.g., vane) upstream or downstream from the blades 486.

In the illustrated embodiment, the second rotational speed 558 is generally the same as the design rotational speed 536 of the rotary machine, and thus the line 542 corresponding to the medium count of blades (e.g., FIG. 16) would likely result in resonant behavior of the structure (e.g., vane) upstream or downstream from the rotating blades 506. Accordingly, the disclosed embodiments may employ either a greater or lesser count of blades to avoid this resonant behavior at the design rotational speed 536 of the rotary machine. For example, the disclosed embodiments may employ the greater count of blades provided by smaller spacers as depicted in FIG. 17, or the lesser count of blades provided by the larger spacers as depicted in FIG. 15. At the design rotational speed 536, the greater count of blades provided by smaller spacers as depicted in FIG. 17 would result in a frequency 564 of oscillations (e.g., wakes or bow waves) substantially greater than the resonant frequency 556, thereby substantially preventing any resonant behavior in the structure (e.g., vane) upstream or downstream from the blades. Similarly, at the design rotational speed 536, the lesser count of blades provided by larger spacers as depicted in FIG. 15 would result in a frequency 566 of oscillations (e.g., wakes or bow waves) substantially lesser than the resonant frequency 556, thereby substantially preventing any resonant behavior in the structure (e.g., vane) upstream or downstream from the blades. Although FIGS. 15-18 represent only three sizes of spacers (i.e., large 482, medium 502, and small 522), any number of differently sized spacers may be used to adjust the count of blades with a uniform blade spacing, thereby avoiding any resonant behavior in the rotary machine.

Similar to the modification of blade spacing of rotating blades as discussed above with reference to FIGS. 15-18, the disclosed embodiments also include modification of vane spacing of stationary vanes as discussed below with reference to FIGS. 19, 20, and 21. FIGS. 19, 20, and 21 illustrate the use of three differently sized spacers to provide a different uniform vane spacing and vane count, which may be selectively used to vary the frequency of wakes and bow waves in a rotary machine such as a turbine or a compressor. Although FIGS. 19, 20, and 21 illustrate only three sizes of spacers (i.e., large, medium, and small), certain embodiments may employ any number of spacer sizes (e.g., 2 to 100 different sizes) to modify the blade spacing and count. In each embodiment, the spacers may be selected to alter the vane count to control the frequency of oscillations (e.g., wakes or bow waves), thereby ensuring that the frequency of oscillations does not coincide with a resonant frequency.

FIG. 19 is a section of a front view of an embodiment of a stator 570 with large spacers 572 between vane bases 574 supporting vanes 576. In the illustrated embodiment, the large spacers 572 have an equal size to separate adjacent vane bases 574 by an equal distance 578 around the stator 570. The large spacers 572 also separate the vanes 576 by an equal distance 580 around the stator 570. Relative to the small and medium spacers as illustrated in FIGS. 20 and 21, the large spacers 572 decrease the number of vanes 576 on the stator 570, thereby decreasing the frequency of the bow and wake waves. The large spacers 572 may be used to shift the frequency of the bow and wake waves away from a resonant frequency, e.g., if the medium or small spacers result in a frequency too close to the resonant frequency.

FIG. 20 is a section of a front view of an embodiment of a stator 590 with medium spacers 592 between vane bases 594 supporting vanes 596. In the illustrated embodiment, the medium spacers 592 have an equal size to separate adjacent vane bases 594 by an equal distance 598 around the stator 590. The medium spacers 592 also separate the vanes 596 by an equal distance 600 around the stator 590. Relative to the large spacers as illustrated in FIG. 19, the medium spacers 592 increase the number of vanes 596 on the stator 590, thereby increasing the frequency of the bow and wake waves. Relative to the small spacers as illustrated in FIG. 21, the medium spacers 592 decrease the number of vanes 596 on the stator 590, thereby decreasing the frequency of the bow and wake waves. The medium spacers 592 may be used to shift the frequency of the bow and wake waves away from a resonant frequency, e.g., if the large or small spacers result in a frequency too close to the resonant frequency.

FIG. 21 is a section of a front view of an embodiment of a stator 610 with small spacers 612 between vane bases 614 supporting vanes 616. In the illustrated embodiment, the small spacers 612 have an equal size to separate adjacent vane bases 614 by an equal distance 618 around the stator 610. The small spacers 612 also separate the vanes 616 by an equal distance 620 around the stator 610. Relative to the large and medium spacers as illustrated in FIGS. 19 and 20, the small spacers 612 increase the number of vanes 616 on the stator 610, thereby increasing the frequency of the bow and wake waves. The small spacers 612 may be used to shift the frequency of the bow and wake waves away from a resonant frequency, e.g., if the large and medium spacers result in a frequency too close to the resonant frequency.

The embodiments discussed above are directed to changing the frequency of wake and bow waves generated by rotating blades or stationary vanes, such that the frequency does not intersect with a resonant frequency of various structures in the fluid flow. As appreciated, the non-uniform spacing or modified count of rotating blades or stationary vanes may be applied to a single stage of a rotary machine (e.g., a turbine or a compressor), or it may be applied to multiple stages in a similar or different configuration. For example, each stage in a compressor or turbine may change the non-uniform spacing or modified count of blades or vanes to address different fluid dynamics in each particular stage. In other words, each stage may exhibit different resonant behavior, frequencies of wake and bow waves, and other characteristics. Thus, the disclosed embodiments may employ a combination of non-uniform spacing and a modified count of blades and vanes to address the different fluid dynamics from one stage to another.

Technical effects of the disclosed embodiments include the ability to dampen fluid oscillations (e.g., wake or bow waves) and/or reduce resonant behavior caused by the fluid oscillations in a rotary machine. In particular, the disclosed embodiments adjust the spacing and/or count of blades or vanes to control the frequency of wake and bow waves formed by the rotating blades, stationary vanes, or other structures in the fluid flow. For example, a non-uniform spacing of rotating blades or stationary vanes may be achieved with differently sized spacers between adjacent blades or vanes, differently sized bases of the blades or vanes, or a combination thereof. By further example, a modified count of rotating blades or vanes may be achieved with different sets of spacers, each configured to provide a different uniform spacing of the blades or vanes. The non-uniform spacing or modified count of blades or vanes is able to reduce the possibility of resonant behavior in the rotary machine, thereby reducing the possibility of costly wear and damage of vanes, blades, and other structures in the fluid flow path.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.