[0001] This application claims priority to U .S. Utility Patent Application having Serial No. 1 4/457,580, which was filed August 12, 2014, and U.S. Provisional Patent Application having Serial No. 61 /876,304, which was filed September 1 1 , 2013. These priority applications are hereby incorporated by reference in their entirety into the present application to the extent consistent with the present application.

Background

[0002] Reliable and efficient compressors, such as centrifugal compressors, have been developed and are often utilized in a myriad of industrial processes (e.g., petroleum refineries, offshore oil production platforms, and subsea process control systems). In the centrifugal compressors, undesirably high levels of noise may be generated near regions of an impeller outlet and a diffuser inlet. For example, in the centrifugal compressor, process fluids may flow through the regions of the impeller outlet and the diffuser inlet at velocities sufficient to generate the high levels of noise. The noise generated may often have a frequency band in a frequency range that human ears may be sensitive to; and thus, may create an undesirable working environment for nearby operators. In addition to presenting a nuisance to the nearby operators, the noise may also result in unintended vibrations and structural damage of the compressors and/or components thereof.

[0003] In view of the foregoing, the compressors may often incorporate noise attenuators to reduce the high levels of noise. For example, external attenuators or devices, such as enclosures and wraps, may often be utilized to reduce the high levels of noise. Utilizing the external devices, however, often leads to increased overall cost as the external devices are often provided as an add-on for the already manufactured compressors. Further, the external devices reduce the high levels of noise by insulating structural components of the compressor, and not by reducing the generation and/or excitation of sound waves traversing along or through fluid passages of the compressors. Due to the limitations of the external devices, internal devices, such as acoustic liners or resonators, have been developed and are often disposed adjacent diffuser channels of the compressors to attenuate the noise generated by the process fluids. The acoustic liners may attenuate the high levels of noise by exploiting the Helmholtz resonance principle. For example, the sound waves generated by the process fluids may oscillate through perforations and/or cells formed in the acoustic liner fluidly coupled with the diffuser channels. The oscillation of the sound waves via the cells may dissipate the acoustic energy and thereby attenuate the noise. The acoustic liner may also attenuate the noise by providing a local impedance mismatch to reflect the acoustic energy upstream. While the acoustic liners may provide a viable option for attenuating the noise, current designs and/or methods for implementing or integrating the acoustic liners in the conventional compressors may be improved. For example, the acoustic liners are often integrated in the conventional compressors such that the cells of the acoustic liners present "dead volumes" to the process fluids flowing through the diffuser channels.

[0004] What is needed, then, is an improved system and method for integrating acoustic liners in a compressor, such that the acoustic liners exhibit increased or enhanced performance in reducing acoustic energy generated in the compressor by introducing a net or biasing flow through the acoustic liners.

Summary

[0005] Embodiments of the disclosure may provide a compressor including a housing that may define a fluid pathway and a shunt hole fluidly coupling the fluid pathway with another component of the compressor. The compressor may also include an impeller at least partially disposed in the fluid pathway and coupled with a rotary shaft. The impeller may be configured to rotate with the rotary shaft to direct a process fluid through the fluid pathway of the compressor. The compressor may further include a disk disposed between the fluid pathway and the shunt hole. The disk may define a plurality of openings fluidly coupling the fluid pathway with the shunt hole and configured to reduce acoustic energy generated in the compressor.

[0006] Embodiments of the disclosure may also provide a method for reducing acoustic energy generated in a compressor. The method may include fluidly coupling a fluid pathway formed in a housing of the compressor with another component of the compressor via a shunt hole. The method may also include rotating a rotary shaft and an impeller coupled with the rotary shaft to direct a process fluid through the fluid pathway to thereby generate the acoustic energy. The method may further include directing a portion of the process fluid from the fluid pathway to the shunt hole via a plurality of openings formed in a disk disposed between the fluid pathway and the shunt hole, such that the generated acoustic energy is reduced.

[0007] Embodiments of the disclosure may further provide another compressor including a housing that may define an impeller cavity and a diffuser channel fluidly coupled with and extending radially outward from the impeller cavity. An impeller may be disposed in the impeller cavity and coupled with a rotary shaft of the compressor. The impeller may be configured to rotate with the rotary shaft to direct a process fluid from the impeller cavity to and through the diffuser channel. The compressor may also include a disk disposed adjacent the diffuser channel and configured to reduce acoustic energy generated in the compressor. The disk may define an upstream opening fluidly coupled with an upstream portion of the diffuser channel, and a downstream opening fluidly coupled with a downstream portion of the diffuser channel. The disk may also define a passage fluidly coupling the upstream opening with the downstream opening.

[0008] Embodiments of the disclosure may also provide another method for reducing acoustic energy generated in a compressor. The method may include rotating a rotary shaft and an impeller coupled with the rotary shaft to direct a process fluid through a diffuser channel formed in a housing of the compressor. The method may also include directing a portion of the process fluid from a downstream portion of the diffuser channel to a downstream opening extending through a disk disposed adjacent the diffuser channel. The method may further include directing the portion of the process fluid from the downstream opening to an upstream opening extending through the disk via a passage formed in the disk to thereby reduce the acoustic energy generated in the compressor.

Brief Description of the Drawings

[0009] The present disclosure is best understood from the following detailed description when read with the accompanying Figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0010] Figure 1 illustrates a partial, cross-sectional view of a compressor including an acoustic liner, according to one or more embodiments disclosed.

[0011] Figure 2A illustrates a partial, cross-sectional view of the acoustic liner of Figure 1 , according to one or more embodiments disclosed.

[0012] Figure 2B illustrates a perspective view of a portion of the acoustic liner of Figure 1 , according to one or more embodiments disclosed.

[0013] Figure 3 illustrates another compressor including a plurality of acoustic liners, according to one or more embodiments disclosed.

[0014] Figure 4 illustrates a partial, cross-sectional view of another compressor including another acoustic liner, according to one or more embodiments disclosed.

[0015] Figure 5A illustrates a partial, cross-sectional view of the acoustic liner of Figure 4, according to one or more embodiments disclosed.

[0016] Figure 5B illustrates a perspective view of a portion of the acoustic liner of Figure 4, according to one or more embodiments disclosed.

[0017] Figure 6 illustrates a flowchart of a method for reducing acoustic energy generated in a compressor, according to one or more embodiments disclosed.

[0018] Figure 7 illustrates a flowchart of another method for reducing acoustic energy generated in a compressor, according to one or more embodiments disclosed.

Detailed Description

[0019] It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the exemplary embodiments presented below may be combined in any combination of ways, i.e. , any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.

[0020] Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Further, in the following discussion and in the claims, the terms "including" and "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to." All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. Furthermore, as it is used in the claims or specification, the term "or" is intended to encompass both exclusive and inclusive cases, i.e., "A or B" is intended to be synonymous with "at least one of A and B," unless otherwise expressly specified herein.

[0021] Figure 1 illustrates a partial, cross-sectional view of a compressor 100 including an acoustic liner 1 40, according to one or more embodiments. The compressor 1 00 may be a centrifugal compressor, an axial compressor, a back-to-back compressor, or the like. In at least one embodiment, the compressor 100 may include one or more compression stages 102. Although the acoustic liner 1 40 is shown in association with a final compression stage 102 in Figure 1 , one of ordinary skill in the art will appreciate that the acoustic liner 1 40 may be associated with other compression stages, including an intermediate compression stage or a first compression stage. The compression stage 1 02 may include an impeller 1 1 6 having an inlet, such as an impeller inlet 1 18, and an outlet, such as an impeller outlet 1 22.

[0022] In an exemplary embodiment, the compressor 100 may include a housing 1 1 2 at least partially defining an impeller cavity 1 1 4 configured to receive the impeller 1 1 6. The housing 1 1 2 may also at least partially define a diffuser channel 126 extending radially outward from and fluidly coupled with the impeller cavity 1 1 4. The impeller cavity 1 14 and the diffuser channel 1 26 fluidly coupled therewith may form at least a portion of a fluid pathway extending through the compressor 1 00 through which the process fluid may be flowed. In at least one embodiment, the impeller 1 1 6 may be at least partially disposed in the impeller cavity 1 1 4 and configured to rotate therein to compress or pressurize the process fluid. For example, the impeller 1 16 may be coupled with a rotary shaft 108 configured to rotate the impeller 1 1 6 at a speed sufficient to draw the process fluid into the impeller cavity 1 1 4 via the impeller inlet 1 18 and compress the process fluid.

[0023] In at least one embodiment, the impeller 1 16 may include a plurality of impeller blades (one is shown 124) disposed about and coupled with the rotary shaft 108. The impeller blades 124 may be configured to discharge or direct the process fluid from the impeller 1 16 to the diffuser channel 126 via the impeller outlet 122. The diffuser channel 1 26 may receive the process fluid from the impeller 1 1 6 and direct the process fluid downstream to a volute 138 formed in the housing 1 1 2. The process fluid directed to the volute 1 38 may be discharged via an outlet (not shown) of the compressor 100. The diffuser channel 1 26 may be configured to convert kinetic energy (e.g., flow velocity) of the process fluid from the impeller 1 1 6 to potential energy (e.g., static pressure) by reducing the flow velocity thereof. Accordingly, the process fluid contained in the diffuser channel 1 26 may have a relatively higher pressure than the process fluid in the impeller 1 16. Further, the process fluid at an upstream portion of the diffuser channel 1 26 may have a relatively lower pressure than the process fluid at a downstream portion of the diffuser channel 1 26. For example, the process fluid at the upstream portion of the diffuser channel 1 26 (e.g., near or proximal the impeller outlet 1 22 of the impeller 1 16) may have a relatively lower pressure than the process fluid at the downstream portion of the diffuser channel 1 26 (e.g., near or proximal the volute 1 38).

[0024] In at least one embodiment, the compressor 1 00 may include a balance piston 120 coupled with the rotary shaft 1 08 and configured to rotate with the rotary shaft 108. In at least one embodiment, the balance piston 1 20 may be positioned adjacent the compression stage 102. In another embodiment, the balance piston 1 20 may be positioned near or proximal a high-pressure side of the impeller 1 1 6. For example, the balance piston 120 may be positioned near or proximal the impeller outlet 1 22 of the impeller 1 16.

[0025] In at least one embodiment, the compressor 100 may include an annular division wall 1 29 coupled with or otherwise forming at least a portion of the housing 1 12. For example, as illustrated in Figure 1 , the division wall 1 29 may form an annular portion of the housing 1 1 2. The division wall 1 29 and/or the housing 1 12 may at least partially define the diffuser channel 1 26 extending radially outward from the impeller cavity 1 1 4. In at least one embodiment, the division wall 129 may be configured to separate a high- pressure portion or side of the compressor 100 from a low-pressure portion or side of the compressor 100. For example, as illustrated in Figure 1 , the division wall 1 29 may be configured to separate a first side, or a high-pressure side 1 28, of the compressor 100 from a second side, or a low-pressure side 130, of the compressor 100.

[0026] In at least one embodiment, the compressor 1 00 may include a sealing substrate 1 32 coupled with or otherwise forming at least a portion of the division wall 1 29. The sealing substrate 1 32 may be fabricated from an abradable material, such as an aluminum alloy, a copper alloy, a powder metal alloy, a graphite-containing ferrous alloy, a polymer, combinations thereof, or the like. In at least one embodiment, the sealing substrate 1 32 may include a seal surface 1 34 configured to reduce leakage of the process fluid from the high-pressure side 128 to the low-pressure side 1 30. As illustrated in Figure 1 , the seal surface 1 34 may define a plurality of teeth extending radially inward toward the balance piston 120 to provide a labyrinth seal. It may be appreciated that the seal surface 134 of the sealing substrate 132 may include or define any type of seal known in the art, including, but not limited to, a hole-pattern seal, an aerodynamic swirl break seal, or the like. [0027] In at least one embodiment, the housing 1 12 may define one or more gas conduits or shunt holes (one is shown 1 36) fluidly coupling the diffuser channel 1 26 or the fluid pathway extending through the compressor 1 00 with another one or more components of the compressor 100. For example, the shunt hole 1 36 may fluidly couple the diffuser channel 1 26 with one or more seals, bearings, carrier rings, balance pistons, rotary shafts, compression stages, or the like, or any combination thereof. In another example, as illustrated in Figure 1 , the shunt hole 136 may fluidly couple the diffuser channel 126 with the balance piston 120 coupled with the rotary shaft 1 08. In another embodiment, the shunt hole 1 36 may fluidly couple the diffuser channel 126 or the fluid pathway extending through the compressor 1 00 with one or more predetermined portions and/or cavities of the compressor 1 00. The predetermined portions and/or cavities of the compressor 100 may have a pressure that may be relatively greater than or relatively less than a pressure of the diffuser channel 1 26 or the fluid pathway extending through the compressor 100. As further described herein, the diffuser channel 1 26 may be in fluid communication with the shunt hole 1 36 via the acoustic liner 140. The shunt hole 136 may be configured to reduce or substantially prevent swirling of the process fluid by directing high-pressure process fluid from the high-pressure side 1 28 to the balance piston 120 and/or the rotary shaft 108. For example, as illustrated in Figure 1 , the shunt hole 1 36 may direct the high- pressure process fluid from the diffuser channel 1 26 to the balance piston 120 to reduce the swirling of the process fluid. Reducing the swirling of the process fluid may reduce aerodynamic cross-coupling effects and improve stability of the rotary shaft 1 08.

[0028] In at least one embodiment, one or more of the acoustic liners (one is shown 1 40) may be disposed in and/or coupled with the housing 1 1 2. For example, as illustrated in Figure 1 , the acoustic liner 140 may be disposed in a recess 141 formed in the division wall 1 29 of the housing 1 12. In at least one embodiment, the acoustic liner 140 may be fluidly coupled between the diffuser channel 126 and the shunt hole 1 36. The acoustic liner 1 40 may be configured to attenuate sound waves generated in the compressor 1 00, thereby reducing or substantially preventing noise associated with the sound waves. The acoustic liner 1 40 may be or include a disk, such as an annular ring or disk 142, disposed radially outward of the impeller 1 16 and coupled with the housing 1 1 2 between the diffuser channel 126 and the shunt hole 136. An upper portion of the annular ring 1 42 is illustrated in Figure 1 and further illustrated in detail in Figures 2A and 2B. [0029] As illustrated in Figures 2A, the annular ring 142 of the acoustic liner 140 may define a series of cells 202, or openings, at least partially extending from a first surface 204 of the annular ring 1 42 toward a second surface 206 of the annular ring 1 42. In at least one embodiment, the cells 202 may be randomly disposed along the first surface 204 of the annular ring 1 42. In another embodiment, the cells 202 may be arranged in an ordered pattern along the first surface 204 of the annular ring 142. For example, as illustrated in Figure 2B, the cells 202 may be arranged as one or more rows extending annularly along the first surface 204 of the annular ring 142. As further illustrated in Figure 2B, the cells 202 in one of the rows may be staggered or offset with respect to the cells 202 in an adjacent row.

[0030] As further illustrated in Figure 2A, the annular ring 142 of the acoustic liner 140 may define a series of holes 208, or openings, extending from an inner end surface 210 of each of the cells 202 to the second surface 206 of the annular ring 1 42. A plurality of the holes 208 may be associated with each of the cells 202. In at least one embodiment, the plurality of holes 208 may be randomly disposed along the inner end surface 21 0 of each of the cells 202. In another embodiment, the plurality of holes 208 may be disposed as an ordered pattern along the inner end surface 210 of each of the cells 202. While Figures 2A and 2B illustrate the cells 202 as having a circular or disc-like cross-section, and the holes 208 as bores, the shapes of the cells 202 and the holes 208 are merely exemplary. Accordingly, it may be appreciated that the shapes of the cells 202 and the holes 208 may vary without departing from the scope of the disclosure. In at least one embodiment, the first surface 204 may be parallel to the second surface 206 and/or the inner end surface 21 0 of the cells 202. In another embodiment, the first surface 204 may be angled or have an angular orientation relative to the second surface 206 and/or the inner end surface 21 0 of the cells 202.

[0031] In at least one embodiment, as illustrated in Figure 1 , the acoustic liner 140 may be coupled with the housing 1 12 such that the first surface 204 of the annular ring 1 42 abuts or is disposed adjacent the division wall 129, thereby providing direct fluid communication between the shunt hole 136 and at least one of the cells 202. While Figure 1 illustrates a single shunt hole 136, the compressor 100 may include a plurality of shunt holes 1 36 where a respective one of the plurality of shunt holes 1 36 may be fluidly coupled with a respective one of the cells 202. It may also be appreciated that a plurality of the cells 202 may be fluidly coupled with the single shunt hole 1 36. The acoustic liner 140 may also be coupled with the housing 1 12 such that the second surface 206 of the annular ring 142 abuts or is disposed adjacent the diffuser channel 1 26, thereby providing direct fluid communication between the diffuser channel 1 26 and the holes 208. Accordingly, the diffuser channel 126 may be fluidly coupled with the shunt hole 136 via the holes 208 and the cells 202 of the acoustic liner 140. In at least one embodiment, fluid communication between the diffuser channel 1 26 and the shunt hole 136 may provide a net or biasing flow of the process fluid from the diffuser channel 126 to the shunt hole 1 36 via the holes 208 and the cells 202, as indicated by arrow 1 44 in Figure 1 .

[0032] As previously discussed, the acoustic liner 1 40 may be configured to attenuate the sound waves generated in the compressor 1 00 to thereby reduce the noise associated with the sound waves. In at least one embodiment, the acoustic liner 140 may be optimized or tuned to attenuate the sound waves having a predetermined frequency or range of frequencies. For example, a volume and/or cross-sectional area of the cells 202 and/or the holes 208 may be varied (i.e., increased and/or decreased) to tune the acoustic liner 1 40 to the predetermined frequency or range of frequencies. In addition to varying the volume and/or the cross-sectional area of the cells 202 and/or the holes 208, the number and/or the length of the cells 202 and/or the holes 208 may be varied to tune the acoustic liner 1 40 to the predetermined frequency or range of frequencies.

[0033] In at least one embodiment, fluidly coupling the diffuser channel 126 with the shunt hole 1 36 via the acoustic liner 1 40 may increase the attenuation of the sound waves generated in the compressor 1 00. For example, without fluid communication through the acoustic liner 1 40, the cells 202 may function as "dead volumes." The biasing flow 144 from the diffuser channel 1 26 to the shunt hole 1 36 via the acoustic liner 1 40 may prevent the cells 202 from functioning as "dead volumes," and allow a flow (e.g. , the biasing flow 1 44) of the process fluid through the acoustic liner 1 40. The flow of the process fluid through the acoustic liner 140 may increase the attenuation of the sound waves and/or allow the acoustic liner 140 to attenuate the sound waves over a broader range of frequencies. [0034] In at least one embodiment, as illustrated in Figure 3, a compressor 300 may include a plurality of acoustic liners (two are shown 301 , 302). The compressor 300 may be similar in some respects to the compressor 1 00 described above and therefore may be best understood with reference to the description of Figure 1 where like numerals designate like components and will not be described again in detail. As illustrated in Figure 3, the compressor 300 may include a first acoustic liner 301 and a second acoustic liner 302 disposed adjacent and/or coupled with one another. The first and second acoustic liners 301 , 302 may be similar in some respects to the acoustic liner 1 40 describe above and therefore may be best understood with reference to the description of Figures 2A and 2B. For example, the first and second acoustic liners 301 , 302 may each include an annular ring 142 having a series of cells 202 partially extending from the first surface 204 of the annular ring 142 toward a second surface 206 of the annular ring 1 42, and a series of holes 208 extending from the second surface 206 to each of the cells 202.

[0035] As illustrated in Figure 3, the second acoustic liner 302 may be disposed adjacent the first acoustic liner 301 such that the second surface 206 of the second acoustic liner 302 abuts the first surface 204 of the first acoustic liner 301 . In at least one embodiment, the first acoustic liner 301 may be serially coupled with the second acoustic liner 302. For example, the first acoustic liner 301 may be coupled with the second acoustic liner 302 such that the cells 202 of the first acoustic liner 301 may be substantially aligned with the cells 202 of the second acoustic liner 302. In another example, the first acoustic liner 301 may be coupled with the second acoustic liner 302 such that the cells 202 of the first acoustic liner 301 may not be substantially aligned with the cells 202 of the second acoustic liner 302, but at least fluidly coupled with the cells 202 of the second acoustic liner 302. Accordingly, the diffuser channel 126 may be fluidly coupled with the shunt hole 1 36 via the first acoustic liner 301 and the second acoustic liner 302. For example, the diffuser channel 1 26 may be fluidly coupled with the shunt hole 136 via the respective holes 208 and cells 202 of the first and second acoustic liners 301 , 302. Serially coupling the first acoustic liner 301 with the second acoustic liner 302 may allow the first and second acoustic liners 301 , 302 to attenuate the sound waves over a broader range of frequencies as compared to the embodiment described with reference to Figure 1 having the single acoustic liner 140. [0036] Figure 4 illustrates another compressor 400 that may be similar in some respects to the compressor 100 described above and therefore may be best understood with reference to the description of Figure 1 where like numerals designate like components and will not be described again in detail. As illustrated in Figure 4, the compressor 400 may include one or more acoustic liners (two are shown 410) disposed in the recesses 1 41 formed in the housing 1 12 and adjacent the diffuser channel 126. A partial, cross- sectional view of the acoustic liner 41 0 is illustrated in Figure 4 and further illustrated in detail in Figures 5A and 5B. The acoustic liner 410 may be similar in some respects to the acoustic liner 140 described above and therefore may be best understood with reference to the description of Figures 2A and 2B where like numerals designate like components and will not be described again in detail.

[0037] As illustrated in Figures 5A and 5B, the acoustic liner 410 may include an inner annular portion 502 and an outer annular portion 504, which may be referred to as an upstream portion 502 and a downstream portion 504, respectively. In at least one embodiment, the annular ring 142 may define one or more channels or passages 506 (five are shown) configured to fluidly couple two or more of the cells 202 with one another. For example, the annular ring 1 42 may define the passages 506 along the first surface 204 of the acoustic liner 410 to fluidly couple the cells 202 with one another. In at least one embodiment, the passages 506 may fluidly couple any one of the cells 202 disposed in the upstream portion 502 (e.g., upstream cell) with any one of the cells 202 disposed in the downstream portion 504 (e.g. , downstream cell).

[0038] In at least one embodiment, as illustrated in Figure 4, the acoustic liner 410 may be coupled with the housing 1 12 such that the second surface 206 of the annular ring 142 abuts or is disposed adjacent the diffuser channel 1 26, thereby providing fluidly communication between the cells 202 and the diffuser channel 126 via the holes 208. The acoustic liner 410 may also be coupled with the housing 1 12 such that the upstream portion 502 may be disposed adjacent the upstream portion of the diffuser channel 126 (e.g., near or proximal the impeller outlet 122 of the impeller 1 1 6), and the downstream portion 504 may be disposed adjacent the downstream portion of the diffuser channel 126 (e.g., near or proximal the volute 138). [0039] As previously discussed, the process fluid at the upstream portion of the diffuser channel 1 26 may have a relatively lower pressure than the process fluid at the downstream portion of the diffuser channel 1 26. Accordingly, the cells 202 disposed in the downstream portion 504 of the acoustic liner 410 may exhibit a relatively higher pressure than cells 202 disposed in the upstream portion 502 of the acoustic liner 41 0, thereby resulting in a pressure differential therebetween. In at least one embodiment, the pressure differential between the upstream portion 502 and the downstream portion 504 may introduce a net or biasing flow of the process fluid from the cells 202 in the downstream portion 504 to the cells 202 in the upstream portion 502 via the passages 506, as indicated by arrow 41 2. The process fluid directed to the cells 202 in the upstream portion 502 may be directed back to the upstream portion of the diffuser channel 1 26 via the respective holes 208 in the upstream portion 502 of the acoustic liner 41 0.

[0040] In at least one embodiment, the biasing flow 41 2 through the passages 506 may increase the attenuation of the sound waves generated in the compressor 400. For example, the biasing flow 41 2 may prevent the cells 202 in the downstream portion 504 from functioning as "dead volumes." The biasing flow 412 of the process fluid from the cells 202 in the downstream portion 504 to the cells 202 in the upstream portion 502 via the passages 506 may allow the acoustic liner 410 to attenuate the sound waves over a broader range of frequencies.

[0041] Figure 6 illustrates a flowchart of a method 600 for reducing acoustic energy generated in a compressor, according to one or more embodiment. The method 600 may include fluidly coupling a fluid pathway formed in a housing of the compressor with another component of the compressor via a shunt hole, as shown at 602. The method 600 may also include rotating a rotary shaft and an impeller coupled with the rotary shaft to direct a process fluid through the fluid pathway, as shown at 604. Directing the process fluid through the fluid pathway may generate the acoustic energy. The method 600 may further include directing a portion of the process fluid from the fluid pathway to the shunt hole via a plurality of openings formed in a disk disposed between the fluid pathway and the shunt hole, as shown at 606.

[0042] Figure 7 illustrates a flowchart of another method 700 for reducing acoustic energy generated in a compressor, according to one or more embodiments. The method 700 may include rotating a rotary shaft and an impeller coupled with the rotary shaft to direct a process fluid through a diffuser channel formed in a housing of the compressor, as shown at 702. The method 700 may also include directing a portion of the process fluid from a downstream portion of the diffuser channel to a downstream opening extending through a disk disposed adjacent the diffuser channel, as shown at 704. The method 700 may further include directing the portion of the process fluid from the downstream opening to an upstream opening extending through the disk via a passage formed in the disk, as shown at 706.

[0043] The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.