U.S. patent application number 15/421845 was filed with the patent office on 2017-08-03 for fluid machine.
This patent application is currently assigned to Hanwha Techwin Co., Ltd.. The applicant listed for this patent is Hanwha Techwin Co., Ltd.. Invention is credited to Kil Young KIM.
Application Number | 20170218979 15/421845 |
Document ID | / |
Family ID | 59386471 |
Filed Date | 2017-08-03 |
United States Patent
Application |
20170218979 |
Kind Code |
A1 |
KIM; Kil Young |
August 3, 2017 |
FLUID MACHINE
Abstract
A fluid machine includes a rotatable hub; a plurality of blades
spaced apart from one another along a circumferential direction
with respect to a rotation center of the hub; and a shroud
extending along a circumferential direction with respect to the
rotation center of the hub and covering the plurality of blades.
The shroud includes: a flow passage, the flow passage formed to be
recessed with respect to an inner surface of the shroud facing the
blades; and a plurality of resonators provided in the flow
passage.
Inventors: |
KIM; Kil Young;
(Changwon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hanwha Techwin Co., Ltd. |
Changwon-si |
|
KR |
|
|
Assignee: |
Hanwha Techwin Co., Ltd.
Changwon-si
KR
|
Family ID: |
59386471 |
Appl. No.: |
15/421845 |
Filed: |
February 1, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/665 20130101;
F04D 29/526 20130101; Y10S 415/914 20130101; F04D 29/685 20130101;
F04D 17/10 20130101; F04D 29/284 20130101; F04D 29/4213
20130101 |
International
Class: |
F04D 29/66 20060101
F04D029/66; F04D 29/68 20060101 F04D029/68; F04D 29/28 20060101
F04D029/28; F04D 17/10 20060101 F04D017/10 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 2, 2016 |
KR |
10-2016-0012899 |
Claims
1. A fluid machine comprising: a rotatable hub; a plurality of
blades spaced apart from one another along a circumferential
direction with respect to a rotation center of the hub; and a
shroud extending along the circumferential direction with respect
to the rotation center of the hub and covering the plurality of
blades, the shroud comprising: a flow passage, the flow passage
formed to be recessed with respect to an inner surface of the
shroud facing the blades; and a plurality of resonators provided in
the flow passage.
2. The fluid machine of claim 1, wherein each of the plurality of
resonators comprises: an opening portion provided on a surface of
the flow passage facing the plurality of blades; and a space
portion connected to the opening and extending radially from the
opening portion, the space portion forming a hollow space in the
shroud.
3. The fluid machine of claim 1 further comprising a base arranged
around the hub, extending along a circumferential direction with
respect to the rotation center of the hub and supporting the
plurality of blades.
4. The fluid machine of claim 1, wherein the shroud comprises: an
inlet portion configured to guide an inflow of fluid toward the
plurality of blades; and an outlet portion configured to guide
discharge of the fluid that has passed through the plurality of
blades.
5. The fluid machine of claim 4, wherein the flow passage extends
from the inlet portion toward the outlet portion and is formed in
at least a partial section of the inner surface of the shroud.
6. The fluid machine of claim 4, wherein the plurality of
resonators are arranged in the flow passage with a uniform density
in an entire area of the flow passage from the inlet portion of the
shroud to the outlet portion.
7. The fluid machine of claim 4, wherein a density of the plurality
of resonators arranged in the flow passage increases from the inlet
portion of the shroud toward the outlet portion.
8. The fluid machine of claim 4, wherein the plurality of
resonators are arranged only in a partial area of an entire area of
the flow passage.
9. The fluid machine of claim 8, wherein the plurality of
resonators are arranged in an area of the flow passage located at a
distance from the inlet portion of the shroud determined by a
preset distance from the inlet portion of the shroud toward the
outlet.
10. The fluid machine of claim 2, wherein the shroud comprises: a
first plate arranged at a position contacting the plurality of
blades and comprising the flow passage and the opening portion of
each of the plurality of resonators; and a second plate provided on
the first plate and comprising the space portion of each of the
plurality of resonators at a position corresponding to the opening
portion of each of the plurality of resonators.
11. A fluid machine comprising: a rotatable hub; a base connected
to the hub and extending radially from the hub; a plurality of
blades provided on the base and spaced apart from one another along
a circumferential direction with respect to a rotation center of
the hub; and a shroud extending along the circumferential direction
with respect to the rotation center of the hub and covering the
plurality of blades, the shroud comprising: an inner surface facing
the base and contacting the plurality of blades; a flow passage
formed to be recessed with respect to the inner surface of the
shroud facing the base; and a plurality of resonators provided in
the flow passage.
12. The fluid machine of claim 11, wherein the shroud comprises: an
inlet portion configured to guide an inflow of fluid toward the
plurality of blades; and an outlet portion configured to guide
discharge of the fluid that has passed through the plurality of
blades.
13. The fluid machine of claim 11, wherein the flow passage
comprises: a first region in which the plurality of resonators are
arranged; and a second region in which none of the plurality of
resonators are provided in the flow passage.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Korean Patent
Application No. 10-2016-0012899, filed on Feb. 2, 2016, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein in its entirety by reference.
BACKGROUND
[0002] 1. Field
[0003] Apparatuses consistent with exemplary embodiments relate to
a fluid machine, and more particularly, to a fluid machine having
improved aerodynamics performance and reduced noise generation.
[0004] 2. Description of the Related Art
[0005] Compressors, expanders, or pumps, which compress or expand
fluid, have a fluid machine using a rotation element. A fluid
machine has an impeller as a rotation element. The impeller
transfers rotational dynamic energy to fluid thereby increasing the
pressure of fluid. The impeller includes a plurality of blades that
guide movement of fluid and transfer energy to the fluid.
[0006] A shroud is arranged outside the impeller, and the shroud
forms a passage for passing fluid together with the blades. In
order to design a fluid machine having superior performance,
aerodynamics performance in the passage formed by the impeller and
the shroud needs to be enhanced.
[0007] However, during an operation of the impeller, high pressure
is generated by the fluid such that loud noise is generated between
the impeller and the shroud. There have been many trials to reduce
noise from operation of the impeller. However, when a separate
apparatus is installed on the impeller or the shroud to reduce
noise, aerodynamic loss is generated in the fluid machine.
[0008] Accordingly, there is a demand for technology to be
developed for reducing noise and simultaneously maintaining
superior aerodynamics performance in the passage between the
impeller and the shroud for passing fluid in the design of a fluid
machine.
[0009] U.S. Pat. No. 5,256,031 discloses that a groove is formed on
a casing wall to reduce vibration. However, a groove-forming
technology such as this seriously increases aerodynamic loss.
[0010] Japanese Publication No. 2007-218147 discloses technology by
which a hole is formed in a shroud to reduce noise. As such, a
simple structure in which a hole is formed in a wall of the shroud
seriously increases aerodynamic loss.
[0011] Japanese Publication No. 2002-537184, Korean Publication No.
1998-0060499, and U.S. Pat. No. 4,540,335 disclose technologies
using a hole to improve noise or improve flow rate properties. In
these technologies, however, because a structure is used in which a
hole is formed at a position of a casing corresponding to a tip
(end portion) of a rotating blade, it is difficult to apply the
structure to improve aerodynamics performance and reduce noise in a
fluid machine using a shroud covering an upper surface of a
rotating blade.
SUMMARY
[0012] One or more exemplary embodiments provide a fluid machine
having reduced noise generation by arranging resonators on a
shroud.
[0013] One or more exemplary embodiments also provide a fluid
machine having resonators for reducing noise and simultaneously
having improved aerodynamics performance.
[0014] Additional aspects will be set forth in part in the
description which follows and, in part, will be apparent from the
description, or may be learned by practice of the presented
exemplary embodiments.
[0015] According to an aspect of an exemplary embodiment, a fluid
machine may include a rotatable hub, a plurality of blades arranged
around the hub and spaced apart from one another along a
circumferential direction with respect to a rotation center of the
hub, and a shroud extending along a circumferential direction with
respect to the rotation center of the hub and covering the blades,
the shroud including a flow passage, the flow passage formed to be
concave with respect to an inner surface facing the blades, and a
plurality of resonators arranged in the flow passage.
[0016] Each of the plurality of resonators may include an opening
opened in a surface of the flow passage facing the plurality of
blades and a space portion connected to the opening and extending
outwardly from the opening, forming a hollow space in the
shroud.
[0017] The fluid machine may further include a base arranged around
the hub, extending along a circumferential direction with respect
to the rotation center of the hub and supporting the plurality of
blades.
[0018] The shroud may include an inlet that guides an inflow of
fluid toward the plurality of blades and an outlet that guides
discharge of the fluid that has passed through the plurality of
blades.
[0019] The flow passage may extend from the inlet toward the outlet
and may be formed in at least a partial section of the inner
surface of the shroud.
[0020] The plurality of resonators may be arranged in the flow
passage with a uniform density in an entire area of the flow
passage from the inlet of the shroud to the outlet.
[0021] A density of the plurality of resonators arranged in the
flow passage may increase from the inlet of the shroud toward the
outlet.
[0022] The plurality of resonators may be arranged only in a
partial area of an entire area of the flow passage from the inlet
of the shroud toward the outlet.
[0023] The plurality of resonators may be arranged in an area of
the flow passage located at a distance from the inlet of the shroud
determined by a preset distance from the inlet of the shroud toward
the outlet.
[0024] The shroud may include a first plate arranged at a position
contacting the plurality of blades and including the flow passage
and the opening of each of the plurality of resonators, and a
second plate arranged above the first plate and including the space
portion of each of the plurality of resonators at a position
corresponding to the opening of each of the plurality of
resonators.
[0025] According to an aspect of another exemplary embodiment, a
fluid machine may include a rotatable hub; a plurality of blades
spaced apart from one another along a circumferential direction
with respect to a rotation center of the hub; and a shroud
extending along the circumferential direction with respect to the
rotation center of the hub and covering the plurality of blades,
the shroud may include: a flow passage, the flow passage formed to
be recessed with respect to an inner surface of the shroud facing
the blades; and a plurality of resonators provided in the flow
passage.
[0026] Each of the plurality of resonators may include: an opening
portion provided on a surface of the flow passage facing the
plurality of blades; and a space portion connected to the opening
and extending radially from the opening portion, the space portion
forming a hollow space in the shroud.
[0027] The fluid machine may further include a base arranged around
the hub, extending along a circumferential direction with respect
to the rotation center of the hub and supporting the plurality of
blades.
[0028] The shroud may include: an inlet portion configured to guide
an inflow of fluid toward the plurality of blades; and an outlet
portion configured to guide discharge of the fluid that has passed
through the plurality of blades.
[0029] The flow passage may extend from the inlet portion toward
the outlet portion and is formed in at least a partial section of
the inner surface of the shroud.
[0030] The plurality of resonators may be arranged in the flow
passage with a uniform density in an entire area of the flow
passage from the inlet portion of the shroud to the outlet
portion.
[0031] A density of the plurality of resonators arranged in the
flow passage may increase from the inlet portion of the shroud
toward the outlet portion.
[0032] The plurality of resonators may be arranged only in a
partial area of an entire area of the flow passage.
[0033] The plurality of resonators may be arranged in an area of
the flow passage located at a distance from the inlet portion of
the shroud determined by a preset distance from the inlet portion
of the shroud toward the outlet.
[0034] The shroud may include: a first plate arranged at a position
contacting the plurality of blades and including the flow passage
and the opening portion of each of the plurality of resonators; and
a second plate provided on the first plate and including the space
portion of each of the plurality of resonators at a position
corresponding to the opening portion of each of the plurality of
resonators.
[0035] According to an aspect of another exemplary embodiment, a
fluid machine may include: a rotatable hub; a base connected to the
hub and extending radially from the hub; a plurality of blades
provided on the base and spaced apart from one another along a
circumferential direction with respect to a rotation center of the
hub; and a shroud extending along the circumferential direction
with respect to the rotation center of the hub and covering the
plurality of blades, the shroud including: an inner surface facing
the base and contacting the plurality of blades; a flow passage
formed to be recessed with respect to the inner surface of the
shroud facing the base; and a plurality of resonators provided in
the flow passage.
[0036] The shroud may include: an inlet portion configured to guide
an inflow of fluid toward the plurality of blades; and an outlet
portion configured to guide discharge of the fluid that has passed
through the plurality of blades.
[0037] The flow passage may include: a first region in which the
plurality of resonators are arranged; and a second region in which
none of the plurality of resonators are provided in the flow
passage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The above and/or other aspects of the disclosure will become
apparent and more readily appreciated from the following
description of the exemplary embodiments, taken in conjunction with
the accompanying drawings in which:
[0039] FIG. 1 is a perspective view of a structure of a fluid
machine according to an exemplary embodiment, in which constituent
elements are disassembled from each other;
[0040] FIG. 2 is a perspective view illustrating an assembled state
of the fluid machine of FIG. 1;
[0041] FIG. 3 is a cross-sectional view taken along a line III-III
of the fluid machine of FIG. 2;
[0042] FIG. 4 is an enlarged cross-sectional view of a portion IV
of the fluid machine of FIG. 3;
[0043] FIG. 5 is a cross-sectional view taken along a line V-V of
the fluid machine of FIG. 2;
[0044] FIG. 6 is a plan view of the fluid machine of FIG. 2;
[0045] FIG. 7 is an enlarged view of a portion of a shroud of the
fluid machine of FIG. 1;
[0046] FIG. 8 is an enlarged view of a portion of a shroud of a
fluid machine according to an exemplary embodiment;
[0047] FIG. 9 is an enlarged view of a portion of a shroud of a
fluid machine according to an exemplary embodiment;
[0048] FIG. 10 is a cross-sectional view of a shroud to illustrate
a process of manufacturing the shrouds of the fluid machines of
FIGS. 1 to 9;
[0049] FIG. 11 is a cross-sectional view of a shroud to illustrate
a process of manufacturing the shrouds of the fluid machines of
FIGS. 1 to 9;
[0050] FIG. 12 is a cross-sectional view of the shroud manufactured
by the process of FIG. 11; and
[0051] FIG. 13 is an enlarged view of a portion of a shroud of a
fluid machine according to an exemplary embodiment.
DETAILED DESCRIPTION
[0052] Reference will now be made in detail to exemplary
embodiments, examples of which are illustrated in the accompanying
drawings, wherein like reference numerals refer to like elements
throughout. In this regard, the exemplary embodiments may have
different forms and should not be construed as being limited to the
descriptions set forth herein. Accordingly, the exemplary
embodiments are merely described below, by referring to the
figures, to explain aspects of the present description. Expressions
such as "at least one of," when preceding a list of elements,
modify the entire list of elements and do not modify the individual
elements of the list.
[0053] FIG. 1 is a perspective view of a structure of a fluid
machine 100 according to an exemplary embodiment, in which
constituent elements are disassembled from each other. FIG. 2 is a
perspective view illustrating an assembled state of the fluid
machine 100 of FIG. 1. FIG. 3 is a cross-sectional view taken along
a line III-III of the fluid machine 100 of FIG. 2.
[0054] The fluid machine 100 according to the exemplary embodiment
illustrated in FIGS. 1 to 3 may include a hub 10, a plurality of
blades 21 arranged on and around the hub 10, and a shroud 30
arranged to cover the blades 21.
[0055] Although rotating machines are implemented by compressors in
the exemplary embodiments illustrated in the drawings, the present
disclosure is not limited thereto. In other words, a rotating
machine according to an exemplary embodiment may be any apparatus
capable of changing the pressure and velocity of fluid by a
rotation motion of an impeller. For example, a rotating machine
according to the exemplary embodiment may be implemented by an
expander (turbine) for expanding fluid, a pump, or a blower.
[0056] The hub 10 has a cylindrical shape and has a shaft coupling
hole 10a, in which a rotation shaft may be inserted. A base 22 is
arranged around the hub 10. Outer diameter of the base 22 increases
along a vertical direction of the center of the hub 10 from the top
to the bottom of the base 22. The base 22 extends in a
circumferential direction with respect to the center of the hub
10.
[0057] The base 22 is coupled to an outer surface of the hub 10 and
the outer diameter of the base 22 increases along a vertical
direction of the center of the hub 10 from the top to the bottom of
the base 22. Because a surface of the base 22 is an inclined curved
surface, the surface of the base 22 forming a bottom surface of a
passage for passing fluid is designed to enable a smooth flow of
the fluid and to transfer maximum energy to the fluid.
[0058] The blades 21 are arranged around the hub 10 to be spaced
apart from one another in a preset interval in a circumferential
direction with respect to a rotation center of the hub 10. The
blades 21 may be arranged on an upper surface of the base 22 and,
as the base 22 is coupled to the outer surface of the hub 10, the
blades 21 may be arranged circumferentially around the hub 10. The
blades 21 extend outwardly from the hub 10 in the radial direction
of the hub 10.
[0059] An impeller 20 including the hub 10, the blades 21, and the
base 22 guides a flow of fluid while simultaneously transferring
dynamic energy of the impeller 20 to the fluid.
[0060] The shroud 30 has an inlet 38 for the fluid formed at an
open upper end portion thereof and an outlet 39 for the fluid
radially and downwardly extending from the inlet 38 at the open
upper end portion. The shroud 30 forms a ceiling surface of the
passage of the fluid. The shroud 30 forms the passage of the fluid
with the base 22 and the blades 21.
[0061] Referring to FIG. 3, as a modified example, when a fluid
machine 100 is designed to be an expander (turbine), the inlet 38
may be manufactured to function as an outlet, whereas the outlet 39
may be manufactured to function as an inlet.
[0062] The inlet 38 of the shroud 30 guides the fluid to be input
toward the blades 21. Furthermore, the outlet 39 of the shroud 30
guides the fluid moved by the blades 21 to be discharged to the
outside of the shroud 30.
[0063] The shroud 30 extends radially from the hub 10 and also
extends in a circumferential direction with respect to the rotation
center of the hub 10 and is arranged covering upper end portions of
the blades 21 as shown in FIG. 2. The shroud 30 and the blades 21
may be fixed to each other, for example, by a welding process or by
using a coupling device such as rivets or bolts. When the shroud 30
and the blades 21 are fixed to each other, the hub 10, the blades
21, and the shroud 30 may rotate together.
[0064] To maintain a fixed position relative to the hub 10 and the
blades 21, for example, the shroud 30 may be fixed on an external
structure instead of the blades 21. When the shroud 30 is fixed on
the external structure, the shroud 30 maintains the fixed position
relative to the hub 10 and the blades 21 during the rotation of the
hub 10 and the blades 21, thereby forming part of the passage.
[0065] When the impeller 20 performs a rotation motion, the fluid
incoming through the inlet 38 of the shroud 30 is discharged to the
outside through the outlet 39 of the shroud 30 by a centrifugal
force. In other words, the fluid is compressed to a high-pressure
state and discharged through the outlet 39 by the centrifugal force
according to rotational dynamic energy of the impeller 20. While
the fluid passes through a diffuser (not shown), for example, the
velocity of the fluid discharged to the outside of the impeller 20
through the outlet 39 decreases and simultaneously the pressure of
the fluid increases to a requested level.
[0066] The shroud 30 may include a flow passage (or a flow passage
surface; hereinafter "a flow passage") 32 formed to be recessed (or
sunken) with respect to an inner surface 30a facing the blades 21
as FIG. 1 (and FIG. 4). The flow passage 32 radially extends from
the inlet 38 of the shroud 30 toward the outlet 39. The shroud 30
may also include a plurality of resonators 40 arranged in the flow
passage 32.
[0067] The flow passage 32 formed in the shroud 30 guides a flow of
the fluid that is moved and compressed by the rotation motion of
the blades 21, thereby enabling the fluid to move smoothly. The
flow passage 32 radially extends from the hub 10 toward the outside
in a direction in which the blades 21 are formed, and is formed to
be curved in the circumferential direction. As such, aerodynamic
loss of the fluid passing between the shroud 30 and the blades 21
may be reduced by the structure of the flow passage 32 formed in
the shroud 30.
[0068] FIG. 4 is an enlarged cross-sectional view of a portion IV
of the fluid machine 100 of FIG. 3. FIG. 5 is a cross-sectional
view taken along a line V-V of the fluid machine 100 of FIG. 2.
FIG. 6 is a plan view of the fluid machine 100 of FIG. 2.
[0069] Each of the plurality of resonators 40 may include an
opening 41 (or an opening portion) opened in a surface of the flow
passage 32 facing the blades 21 and a space portion 42 connected to
the opening 41 and extending from the opening 41 to the outside,
thereby forming an hollow space in the shroud 30.
[0070] Each of the opening 41 and the space portion 42 may have a
circular or polygonal cross-section. Furthermore, the size of a
cross-section of the space portion 42 is larger than the size of a
cross-section of the opening 41 as shown in FIG. 4.
[0071] Because the resonators 40 are formed on the surface of the
flow passage 32 that guides the flow of the fluid so that the fluid
smoothly flows between the blades 21 and the shroud 30, noise that
may be generated by air compressed at high pressure between the
blades 21 and the shroud 30 may be reduced.
[0072] A sectional area, a size, and an arrangement position of the
opening 41 and the space portion 42 of each of the resonators 40
are designed according to a frequency of noise generated between
the shroud 30 and the blades 21. In other words, values such as the
length and the sectional area of the opening 41 formed from the
surface of the flow passage 32 to the space portion 42, and the
volume of the space portion 42, may be experimentally designed
according to a resonance frequency that may be generated between
the shroud 30 and the blades 21.
[0073] FIG. 7 is an enlarged view of a portion of a shroud of the
fluid machine 100 of FIG. 1.
[0074] The flow passage 32 formed in the shroud 30 is formed on an
inner surface of in the shroud 30 (facing the base 22) and extends
from the inlet 38 toward the outlet 39. Although, in the exemplary
embodiment of FIG. 7, the flow passage 32 is formed in the entire
section of the inner surface of the shroud 30 from the inlet 38 of
the shroud 30 toward the outlet 39, the length of the flow passage
32 is not limited thereto. For example, the flow passage 32 may be
formed only in a partial section of the inner surface of the shroud
30 from the inlet 38 of the shroud 30 toward the outlet 39.
[0075] Referring to FIG. 7, the resonators 40 are arranged such
that the resonators 40 have the uniform density in the entire area
of the flow passage 32 from the inlet 38 of the shroud 30 toward
the outlet 39. Accordingly, as illustrated in FIG. 7, a distance d
between the resonators 40 arranged adjacent to the inlet 38 is the
same as a distance d between the resonators 40 arranged adjacent to
the outlet 39. Accordingly, a noise reduction effect of the same
level may be obtained with respect to the entire area of the flow
passage 32 from the inlet 38 of the shroud 30 toward the outlet
39.
[0076] FIG. 8 is an enlarged view of a portion of a shroud 130 of a
fluid machine 100 according to an exemplary embodiment.
[0077] The shroud 130 of a fluid machine 100 according to the
exemplary embodiment has a similar structure to the structure of
the shroud 30 of FIG. 7, except for the arrangement density of a
plurality of resonators 140.
[0078] Referring to FIG. 8, the arrangement density of the
resonators 140 varies in the entire area from an inlet 138 of the
shroud 130 toward an outlet 139. The density of the resonators 140
arranged in the flow passage 132 increases from the inlet 138 of
the shroud 130 toward the outlet 139.
[0079] As illustrated in FIG. 8, a distance d.sub.2 between the
resonators 140 arranged adjacent to the outlet 139 is less than a
distance d.sub.1 between the resonators 140 arranged adjacent to
the inlet 138. Accordingly, the noise reduction effect of the
resonators 140 is higher at the outlet 139 than the inlet 138 of
the shroud 130. As such, a structure in which the density of the
resonators 140 arranged adjacent to the outlet 139 is higher than
the density of the resonators 140 arranged adjacent to the inlet
138 may be applied to a case in which the noise generated at the
outlet 139 is greater than the noise generated at the inlet
138.
[0080] FIG. 9 is an enlarged view of a portion of a shroud 230 of a
fluid machine 100 according to an exemplary embodiment.
[0081] The shroud 230 of a fluid machine 100 according to the
exemplary embodiment has a similar structure to the structure of
the shroud 30 of FIG. 7, except for the arrangement position of a
plurality of resonators 240.
[0082] Referring to FIG. 9, the resonators 240 are arranged only in
a partial area of the entire area of a flow passage 232 from an
inlet 238 of the shroud 230 to an outlet 239. The resonators 240
are arranged in an area of the flow passage 232 located at a
distance from the inlet 238 of the shroud 230 determined by a
preset distance d.sub.0 from the inlet 238 of the shroud 230 toward
the outlet 239.
[0083] The density at which the resonators 240 are arranged in the
flow passage 232 may be set to be uniform in the entire area of the
flow passage 232. When the resonators 240 are arranged so that the
density of the resonators 240 is uniform, a distance d.sub.3
between the resonators 240 adjacent to the inlet 238 is the same as
a distance d.sub.4 between the resonators 240 adjacent to the
outlet 239.
[0084] The present disclosure is not limited to the structure in
which the density of the resonators 240 arranged in the flow
passage 232 is uniform in the entire area of the flow passage 232
as illustrated in FIG. 9. For example, the distance d.sub.3 between
the resonators 240 adjacent to the inlet 238 may be designed to be
different from the distance d.sub.4 between the resonators 240
adjacent to the outlet 239, by modifying the arrangement of the
resonators 240 illustrated in FIG. 9.
[0085] In the above-described structures of the shroud 230 and the
resonators 240, because the resonators 240 are not arranged in an
area covered by the preset distance d.sub.0 in a direction from the
inlet 238 of the shroud 230 toward the outlet 239, a smooth flow of
fluid may be formed in an area of the flow passage 232 where the
resonators 240 are not arranged. Furthermore, the noise reduction
effect may be increased by arranging the resonators 240 in an area
of the flow passage 232 located at a distance from the inlet 238 of
the shroud 230 determined by the preset distance d.sub.0 from the
inlet 238 of the shroud 230 toward the outlet 239, the area
corresponding to an area of the entire area of the flow passage 232
in which noise is much increased.
[0086] Although in the above-described embodiments the sizes, that
is, the diameter, the length, and the volume of the opening, and
the volume of the space portion, of the resonators formed in the
shroud are described as being constant, the sizes of the resonators
may be changed according to the positions of the resonators
arranged in the flow passage of the shroud. For example, the sizes
of the openings and the space portions of the resonators arranged
adjacent to the inlet of the shroud may be designed to be
relatively small, whereas the sizes of the openings and the space
portions of the resonators arranged adjacent to the outlet of the
shroud may be designed to be relatively large. Furthermore, the
sizes of the resonators may be modified to be gradually increased
or decreased from the inlet of the shroud toward the outlet.
[0087] FIG. 10 is a cross-sectional view of a shroud to illustrate
a process of manufacturing the shrouds of the fluid machines of
FIGS. 1 to 9.
[0088] FIG. 10 illustrates an example of a process of manufacturing
a shroud 330 of a fluid machine using a mold. When fluid is
injected between an upper mold 7 and a lower mold 8, which are
coupled to each other, and then cured, the shroud 330 having a flow
passage 332 formed to be recessed (or sunken) in one surface
thereof is completed. Because the lower mold 8 has a shape
corresponding to the resonators 340 of the flow passage 332 of the
shroud 330, the resonators 340, which include an opening 341 in a
surface of the flow passage 332 and a space portion 342 extending
from the opening 341 to the outside and forming an inner space in
the shroud 330, are formed in a surface of the flow passage 332 of
the shroud 330.
[0089] The upper mold 7 and the lower mold 8 are removed after the
shroud 330 is cured, and the surface of the shroud 330 is washed
out, thereby completing the manufacture of the shroud 330.
[0090] FIG. 11 is a cross-sectional view of a shroud to illustrate
a process of manufacturing the shrouds of the fluid machines of
FIGS. 1 to 9. FIG. 12 is a cross-sectional view of the shroud
manufactured by the process of FIG. 11.
[0091] FIGS. 11 and 12 illustrate an example of a process of
manufacturing a shroud 430 of a fluid machine 100 by a method of
combining two metal plates.
[0092] Referring to FIG. 11, the process of manufacturing a shroud
430 may include preparing a first plate 430a, preparing a second
plate 430b, and bonding the first plate 430a and the second plate
430b.
[0093] The first plate 430a is a constituent element forming an
inner surface of the shroud 430 contacting a blade. The preparing
of the first plate 430a may include an operation of, for example,
forming an opening 441 and a flow passage 432 by preparing a metal
plate and applying at least one of various processing methods such
as punching, hammering, pressing, and bending, to the metal
plate.
[0094] The second plate 430b is a constituent element forming an
outer surface of the shroud 430 opposite to the inner surface
contacting the blade. The preparing of the second plate 430b may
include an operation of, for example, forming a space portion 442
by preparing a metal plate and applying at least one of various
processing methods such as punching, hammering, pressing, and
bending, to the metal plate.
[0095] When the first plate 430a and the second plate 430b are
prepared, the positions of the first plate 430a and the second
plate 430b are aligned to each other such that the opening 441 of
the first plate 430a and the space portion 442 of the second plate
430b correspond to each other, and the first plate 430a and the
second plate 430b are bonded to each other.
[0096] The first plate 430a and the second plate 430b may be bonded
to each other by various methods, for example, coating an adhesive
between the first plate 430a and the second plate 430b, using a
coupling device such as rivets or bolts penetrating through the
first plate 430a and the second plate 430b, or welding edges of
inner sides of the first plate 430a and the second plate 430b.
[0097] The manufacture of the shroud 430, completed through the
above-described operations, is arranged at a position contacting
the blade and may include the first plate 430a having the flow
passage 432 and the opening 441, and the second plate 430b having
the space portion 442 at a position corresponding to the opening
441. In a state in which the first plate 430a and the second plate
430b are bonded to each other, the opening 441 of the first plate
430a and the space portion 442 of the second plate 430b are
connected to each other so that a plurality of resonators 440 are
formed.
[0098] FIG. 13 is an enlarged view of a portion of a shroud 530 of
a fluid machine 100 according to an exemplary embodiment.
[0099] The shroud 530 according to an exemplary embodiment of FIG.
13 may include a first plate 530a having a flow passage 532 formed
on an inner surface thereof and a second plate 530b manufactured to
have an outer shape corresponding to the flow passage 532 and
having a plurality of holes 535 of a hexagonal shape having a
beehive arrangement.
[0100] When the second plate 530b is coupled to each flow passage
532 of the first plate 530a, the shroud 530 is thus completed, and
the holes 535 having a hexagonal shape and a beehive arrangement
are arranged on a surface of the flow passage 532 of the shroud 530
facing blades.
[0101] According to the shroud 530 having the above structure,
because the holes 535 in a beehive arrangement are provided on the
flow passage 532 that smoothly guides a flow of fluid, a reduction
in aerodynamic loss and a noise reduction effect may be obtained
simultaneously.
[0102] As described above, in the fluid machine according to the
above-described exemplary embodiments, aerodynamic loss of fluid
passing between the shroud and the blades may be reduced due to the
structure of the flow passage formed in the shroud.
[0103] Furthermore, because the resonators are arranged in the
surface of the flow passage that guides the flow of fluid so that
the fluid may smoothly flows between the blades and the shroud,
noise that may be generated between the blades and the shroud by
air compressed at high pressure may be reduced.
[0104] It should be understood that embodiments described herein
should be considered in a descriptive sense only and not for
purposes of limitation. Descriptions of features or aspects within
each embodiment should typically be considered as available for
other similar features or aspects in other embodiments.
[0105] While exemplary embodiments have been described with
reference to the figures, it will be understood by those of
ordinary skill in the art that various changes in form and details
may be made therein without departing from the spirit and scope as
defined by the following claims.
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