U.S. patent number 10,385,877 [Application Number 15/421,845] was granted by the patent office on 2019-08-20 for fluid machine.
This patent grant is currently assigned to HANWHA POWER SYSTEMS CO., LTD. The grantee listed for this patent is HANWHA POWER SYSTEMS CO., LTD.. Invention is credited to Kil Young Kim.
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United States Patent |
10,385,877 |
Kim |
August 20, 2019 |
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 POWER SYSTEMS CO., LTD. |
Changwon-si |
N/A |
KR |
|
|
Assignee: |
HANWHA POWER SYSTEMS CO., LTD
(Changwon-si, KR)
|
Family
ID: |
59386471 |
Appl.
No.: |
15/421,845 |
Filed: |
February 1, 2017 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20170218979 A1 |
Aug 3, 2017 |
|
Foreign Application Priority Data
|
|
|
|
|
Feb 2, 2016 [KR] |
|
|
10-2016-0012899 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D
29/665 (20130101); F04D 17/10 (20130101); F04D
29/284 (20130101); F04D 29/526 (20130101); F04D
29/685 (20130101); F04D 29/4213 (20130101); Y10S
415/914 (20130101) |
Current International
Class: |
F04D
29/66 (20060101); F04D 29/68 (20060101); F04D
29/52 (20060101); F04D 29/28 (20060101); F04D
17/10 (20060101); F04D 29/42 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
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|
|
2002-537184 |
|
Nov 2002 |
|
JP |
|
2007-218147 |
|
Aug 2007 |
|
JP |
|
1998-060499 |
|
Oct 1998 |
|
KR |
|
Primary Examiner: Bertheaud; Peter J
Attorney, Agent or Firm: Sighrue Mion, PLLC
Claims
What is claimed is:
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, 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, 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.
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 portion 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 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.
5. 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, 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, and 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.
6. The fluid machine of claim 5, wherein the plurality of
resonators are arranged only in a partial area of an entire area of
the flow passage.
7. 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, 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, wherein the
plurality of resonators are arranged only in a partial area of an
entire area of the flow passage, and 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 portion.
8. 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, 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 portion and extending radially from the
opening portion, the space portion forming a hollow space in the
shroud, and 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.
9. 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.
10. The fluid machine of claim 9, 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.
11. The fluid machine of claim 9, 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
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
1. Field
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.
2. Description of the Related Art
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.
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.
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.
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.
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.
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.
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
One or more exemplary embodiments provide a fluid machine having
reduced noise generation by arranging resonators on a shroud.
One or more exemplary embodiments also provide a fluid machine
having resonators for reducing noise and simultaneously having
improved aerodynamics performance.
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.
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.
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.
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.
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.
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.
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.
A density of the plurality of resonators arranged in the flow
passage may increase from the inlet of the shroud toward the
outlet.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
The plurality of resonators may be arranged only in a partial area
of an entire area of the flow passage.
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.
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.
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.
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.
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
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:
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;
FIG. 2 is a perspective view illustrating an assembled state of the
fluid machine of FIG. 1;
FIG. 3 is a cross-sectional view taken along a line III-III of the
fluid machine of FIG. 2;
FIG. 4 is an enlarged cross-sectional view of a portion IV of the
fluid machine of FIG. 3;
FIG. 5 is a cross-sectional view taken along a line V-V of the
fluid machine of FIG. 2;
FIG. 6 is a plan view of the fluid machine of FIG. 2;
FIG. 7 is an enlarged view of a portion of a shroud of the fluid
machine of FIG. 1;
FIG. 8 is an enlarged view of a portion of a shroud of a fluid
machine according to an exemplary embodiment;
FIG. 9 is an enlarged view of a portion of a shroud of a fluid
machine according to an exemplary embodiment;
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;
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; and
FIG. 13 is an enlarged view of a portion of a shroud of a fluid
machine according to an exemplary embodiment.
DETAILED DESCRIPTION
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
FIG. 7 is an enlarged view of a portion of a shroud of the fluid
machine 100 of FIG. 1.
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.
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.
FIG. 8 is an enlarged view of a portion of a shroud 130 of a fluid
machine 100 according to an exemplary embodiment.
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.
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.
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.
FIG. 9 is an enlarged view of a portion of a shroud 230 of a fluid
machine 100 according to an exemplary embodiment.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
FIG. 13 is an enlarged view of a portion of a shroud 530 of a fluid
machine 100 according to an exemplary embodiment.
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.
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.
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.
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.
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.
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.
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.
* * * * *