JP2022183927A - Sound pressure generation device - Google Patents

Abstract

To provide a sound pressure generation device capable of suppressing distortion of sound pressure.SOLUTION: A sound pressure generation device comprises a tube part which has a flow passage extending in a tube axis direction, a rotor which is in a column shape having a colum axis extending in a direction crossing the tube axis direction in the flow passage, and generates sound pressure through rotation on the column axis, and a drive part which rotates the rotor, and also has a first peak part and a second peak part where a cross-sectional shape of the rotor crossing the column axis is pointed, and a long axis where the first peak part and second peak part are located side by side.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a sound pressure generator.

A sound pressure generator is used as a sound source for the acoustic test.

For example, Patent Literature 1 discloses a sound pressure generator that vibrates a dynamic valve with respect to a static valve.

Japanese Utility Model Laid-Open No. 4-129198

In acoustic testing, sound pressure with a waveform with little distortion is desired.
However, in the sound pressure generator disclosed in Patent Document 1, the sound pressure waveform may be distorted.

An object of the present disclosure is to provide a sound pressure generator capable of suppressing distortion of sound pressure.

In order to solve the above problems, a sound pressure generating device according to the present disclosure has a pipe portion having a flow path extending in a pipe axis direction, and a columnar shaft extending in a direction intersecting the pipe axis direction within the flow path. A rotor having a columnar shape and capable of generating sound pressure by rotation about the column axis; has a sharp first apex, a sharp second apex, and a long axis with which the first apex and the second apex are aligned.

According to the sound pressure generator of the present disclosure, distortion of sound pressure can be suppressed.

1 is a conceptual diagram showing an installation state of a combustor in a gas turbine according to the first embodiment of the present disclosure; FIG. 1 is a conceptual diagram of a test facility according to a first embodiment of the present disclosure; FIG. 1 is a front view of a sound pressure generator according to a first embodiment of the present disclosure; FIG. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3; 4 is a table showing cross-sectional shape patterns of the rotor according to the first embodiment of the present disclosure; It is a figure which shows operation|movement of the sound pressure generator which concerns on 1st embodiment of this indication. 4 is a graph showing a waveform of sound pressure generated by the sound pressure generator according to the first embodiment of the present disclosure; 4 is a graph showing the sound pressure level of each harmonic component of the sound pressure generated by the sound pressure generator according to the first embodiment of the present disclosure; FIG. 4 is a cross-sectional view of a rotor according to a comparative example; 7 is a graph showing a sound pressure waveform of a sound pressure generator according to a comparative example; FIG. 4 is a front view of a sound pressure generator according to a second embodiment of the present disclosure; FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11; 7 is a table showing cross-sectional shape patterns of the rotor according to the second embodiment of the present disclosure; 7 is a graph showing a waveform of sound pressure generated by the sound pressure generator according to the second embodiment of the present disclosure; 7 is a graph showing the sound pressure level of each harmonic component of the sound pressure generated by the sound pressure generator according to the second embodiment of the present disclosure; FIG. 11 is a conceptual diagram of a test facility according to a modified example of the present disclosure;

Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. The same reference numerals are given to the same or corresponding configurations in all the drawings, and common explanations are omitted.

<First embodiment>
A sound pressure generator according to the first embodiment will be described with reference to FIGS. 1 to 8. FIG.

(Overall configuration of test facility)
The test equipment 9 is equipment for testing the acoustic performance of the acoustic device.
For example, the test facility 9 may be a facility for testing the acoustic performance of the acoustic device 6 provided in the combustor 7 of the gas turbine 8 as shown in FIG.
The acoustic device 6 is a device for damping vibrations generated in the combustor 7 during combustion.

As shown in FIG. 2 , the test equipment 9 includes a sound pressure generator 1 , piping 2 and an air source 3 .
For example, test facility 9 may be used during component testing of acoustic device 6 .
The element test of the acoustic device 6 may be performed only for the combustor 7 provided with the acoustic device 6 in the gas turbine 8, for example, as shown in FIG.

The pipe 2 extends from the sound pressure generator 1 into the combustor 7 .
For example, the pipe 2 may be a straight pipe extending from the sound pressure generator 1 into the combustor 7 .

Air source 3 sends air to pipe 2 via sound pressure generator 1 .
For example, air source 3 may be a compressor, fan, or the like.

The test fixture 9 may further comprise a test lid 4 .
The test lid 4 closes the opening of the combustor 7 on the sound pressure generator 1 side around the pipe 2 .
The pipe 2 penetrates the test lid 4 and extends into the combustor 7 .

(Configuration of sound pressure generator)
The sound pressure generator 1 is a device for generating sound pressure by vibrating air.
As shown in FIG. 3 , the sound pressure generator 1 includes a tube portion 11, a rotor 12, and a driving portion 13. As shown in FIG.
For example, the sound pressure generator 1 may be provided between the air source 3 and the pipe 2 .
For example, the sound pressure generator 1 may generate sound pressure by vibrating the air sent from the air source 3 to the pipe 2 .

(Structure of tube)
The pipe portion 11 has a flow path A11 extending in the pipe axial direction DT.
For example, the pipe portion 11 may communicate with the pipe 2 so that the air sent from the air source 3 is guided to the pipe 2 via the flow path A11.
For example, the channel A11 may be a rectangular channel having a rectangular cross section perpendicular to the pipe axis direction DT.
For example, the direction in which the columnar axis CX extends may be the Y direction, and the tube axis direction DT may be the Z direction.
For example, the Y direction may be orthogonal to the Z direction, and the direction orthogonal to the Z and Y directions may be the X direction.

(Configuration of rotor)
The rotor 12 has a columnar shape having a columnar axis CX extending in a direction intersecting with the tube axis direction DT within the flow path A11.
The rotor 12 can generate sound pressure by rotating around the columnar axis CX.
As shown in FIG. 4, the cross-sectional shape SS of the rotor 12 crossing the columnar axis CX has a sharp first apex TP1, a sharp second apex TP2, and a first apex TP1 and a second apex TP2. and long axis LX.
For example, the cross-sectional shape SS of the rotor 12 crossing the columnar axis CX may further have a short axis SX that is shorter than the long axis LX and perpendicular to the long axis LX.
Here, the "major axis" is the longest line segment uniquely determined among the line segments drawn from the outer periphery to the outer periphery of the cross-sectional shape SS.
The "minor axis" is the uniquely determined shortest line segment drawn from the outer circumference to the outer circumference of the cross-sectional shape SS.

For example, the first apex TP1 and the second apex TP2 may have sharp tips.
For example, the first apex TP1 and the second apex TP2 may be curved and pointed.

For example, the cross-sectional shape SS of the rotor 12 may be symmetrical about the long axis LX. Furthermore, the cross-sectional shape SS of the rotor 12 may be symmetrical about the minor axis SX. At that time, the cross-sectional shape SS of the rotor 12 may be a cross-sectional shape that vertically crosses the columnar axis CX.
For example, the cross-sectional shape SS of the rotor 12 may be a shape elongated in the direction in which the long axis LX extends.
For example, the cross-sectional area of the flow path A11 whose cross-section is perpendicular to the tube axis direction DT and the cross-sectional area of the rotor 12 whose cross-section is a plane including the long axis LX and the column axis CX are substantially the same. may

For example, the cross-sectional shape SS of the rotor 12 may have a shape in which the first apex TP1 and the second apex TP2 are connected by a pair of arcs CA.
For example, the cross-sectional shape SS of the rotor 12 is defined by two circles passing through the first apex TP1 and the second apex TP2 and having a diameter greater than the distance between the first apex TP1 and the second apex TP2. It may be in shape. The diameters of the two circles may then be equal to each other.
For example, the cross-sectional shape SS of the rotor 12 may be a cross-sectional shape obtained by vertically dividing a rugby ball into two halves.

For example, the flow path A11 may have a duct diameter DD in a direction perpendicular to the column axis CX, and the diameter of the pair of arcs CA may be larger than the duct diameter DD.

Valve. As in D, for example, in the cross-sectional shape SS of the rotor 12, the ratio of the length of the minor axis SX to the diameter of each arc CA of the pair of arcs CA may be 40/49.6 or less.
Valve. As in E, for example, in the cross-sectional shape SS of the rotor 12, the ratio of the length of the minor axis SX to the diameter of each arc CA of the pair of arcs CA may be 30/49.6 or less.
Valve. Like F, for example, in the cross-sectional shape SS of the rotor 12, the ratio of the length of the minor axis SX to the diameter of each arc CA of the pair of arcs CA may be 20/49.6 or less.
5, "diameter" indicates the diameter of each arc CA of a pair of arcs CA, and "width" indicates the length of the minor axis SX in the cross-sectional shape SS of the rotor 12. As shown in FIG.

(Structure of drive unit)
The drive unit 13 rotates the rotor 12 .
For example, the drive unit 13 may rotate the rotor 12 around the columnar axis CX with the columnar axis CX as the center.
For example, the driving section 13 may be a motor.

(motion)
The operation of the sound pressure generator 1 of this embodiment will be described.
As shown in FIG. 6, air AIR is sent from the air source 3 to the flow path A11.
At that time, when the rotor 12 rotates, the first top portion TP1 and the second top portion TP2 move toward or away from the inner wall 11W of the tube portion 11 defining the flow path A11.
When the first top portion TP1 and the second top portion TP2 approach the inner wall 11W, the flow path A11 is blocked, making it difficult for the air AIR to flow.
On the other hand, when the first apex TP1 and the second apex TP2 are separated from the inner wall 11W, the flow path A11 is widened, and the air AIR can easily flow.
Therefore, when the rotor 12 rotates, the conductance of the flow path A11 changes periodically.
Therefore, the flow rate of the air AIR periodically fluctuates according to the periodic change in the conductance of the flow path A11, and sound pressure is generated.

(Action and effect)
According to the present embodiment, the cross-sectional shape SS of the rotor 12 has a pair of pointed apexes aligned with the long axis LX, and the time during which the rotor 12 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 1 can suppress distortion of sound pressure.
It should be noted that the sound pressure generator 1 can generate a large sound pressure if the distortion of the sound pressure can be suppressed.

Further, according to one example of the present embodiment, the cross-sectional shape SS of the rotor 12 is composed of curved lines so as to have a shape connected by a pair of arcs CA.
Therefore, harmonics of sound pressure can be suppressed.

Further, according to one example of the present embodiment, as shown in FIG. 7, in the waveform of the sound pressure generated by the sound pressure generator 1, in the RG1 region where the rotor 12 closes the flow path A11, the sound The waveform of the pressure shows a waveform wider than a sine wave, but in the RG2 region where the rotor 12 opens the flow path A11, the waveform of the sound pressure shows a waveform close to a sine wave.
On the other hand, according to one example of the present embodiment, as shown in FIG. 8, the harmonic components of the sound pressure generated by the sound pressure generator 1 are suppressed.

As a comparative example, in the case of a rotor having a shape in which a part of the peripheral surface of a cylinder is shaved as shown in FIG. 9, the time period during which the rotor blocks the flow path A11 is longer than in the present embodiment.
Therefore, as shown in FIG. 10, the sound pressure is distorted.

In contrast, according to the present embodiment, as described above, the time period during which the rotor 12 blocks the flow path A11 can be shortened.
As a result, compared to the comparative example, the sound pressure generator 1 can generate a sound pressure having a waveform close to a sine wave with suppressed harmonics, as shown in FIGS.

Further, according to the example of the present embodiment, since the cross-sectional shape SS of the rotor 12 is symmetrical about the long axis LX, the sound pressure generator 1 can further suppress distortion of sound pressure.

Further, according to one example of the present embodiment, in the cross-sectional shape SS of the rotor 12, the first apex TP1 and the second apex TP2 have a curvature and are sharp, so the soundness of the sound pressure generator 1 is improved. improves.

Further, according to one example of the present embodiment, the cross-sectional shape SS of the rotor 12 has a shape in which the first apex TP1 and the second apex TP2 are connected by a pair of arcs CA.
As a result, the cross-sectional shape SS of the rotor 12 becomes a shape in which circles are overlapped, so that the rotor 12 can be configured in a simple shape.
Therefore, it is easy to design and manufacture the rotor 12 .

Further, according to one example of this embodiment, the diameter of each arc CA of the pair of arcs CA is larger than the duct diameter DD.
Therefore, the rotor 12 can be made thin so that the bulge in the cross-sectional shape SS in the direction intersecting with the long axis LX is reduced.
As a result, the time during which the rotor 12 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 1 can further suppress distortion of sound pressure.

Further, according to one example of the present embodiment, in the cross-sectional shape SS of the rotor 12, the ratio of the length of the minor axis SX to the diameter of each arc CA of the pair of arcs CA is 40/49.6 or less.
Furthermore, according to one example of the present embodiment, in the cross-sectional shape SS of the rotor 12, the ratio of the length of the minor axis SX to the diameter of each arc CA of the pair of arcs CA is 30/49.6 or less.
Furthermore, according to one example of the present embodiment, in the cross-sectional shape SS of the rotor 12, the ratio of the length of the minor axis SX to the diameter of each arc CA of the pair of arcs CA is 20/49.6 or less.
Therefore, the rotor 12 can be made thin so that the bulge of the cross-sectional shape SS of the rotor 12 toward the short axis SX is reduced.
As a result, the time during which the rotor 12 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 1 can further suppress distortion of sound pressure.

Further, according to one example of the present embodiment, the cross-sectional area of the flow path A11 whose cut surface is a plane perpendicular to the tube axis direction DT, and the rotor 12 whose cut surface is a plane including the major axis LX and the columnar axis CX is approximately the same as the cross-sectional area of
Therefore, the rotor 12 can temporarily close the flow path A11.
Therefore, the sound pressure generator 1 can generate a large sound pressure.

<Second embodiment>
Next, a second embodiment of the present disclosure will be described with reference to FIGS. 11 to 15. FIG.
The configuration of the sound pressure generator 101 of this embodiment is the same as the configuration of the sound pressure generator 1 of the first embodiment, except for the points described below.

(Configuration of sound pressure generator)
As shown in FIG. 11, the sound pressure generator 101 includes a tube portion 11, a rotor 112, and a driving portion 13. As shown in FIG.
For example, the test equipment 9 may include a sound pressure generator 101 instead of the sound pressure generator 1 .

(Configuration of rotor)
The rotor 112 has a columnar shape having a columnar axis CX extending in a direction intersecting with the pipe axis direction DT within the flow path A11.
The rotor 112 can generate sound pressure by rotating around the columnar axis CX.

As shown in FIG. 12, the cross-sectional shape SS of the rotor 112 crossing the columnar axis CX has a sharp first top portion TP1, a sharp second top portion TP2, and the first top portion TP1 and the second top portion TP2. and long axis LX.
For example, the cross-sectional shape SS of the rotor 112 may further have a short axis SX that is shorter than the long axis LX and orthogonal to the long axis LX.

For example, the first apex TP1 and the second apex TP2 may have sharp tips.
For example, the first apex TP1 and the second apex TP2 may be curved and pointed.

For example, the cross-sectional shape SS of the rotor 112 may be symmetrical about the long axis LX. Furthermore, the cross-sectional shape SS of the rotor 112 may be symmetrical about the minor axis SX. At that time, the cross-sectional shape SS of the rotor 112 may be a cross-sectional shape that vertically crosses the columnar axis CX.
For example, the cross-sectional shape SS of the rotor 112 may be a shape elongated in the direction in which the long axis LX extends.
For example, the cross-sectional area of the flow path A11 whose cross-sectional surface is perpendicular to the pipe axis direction DT and the cross-sectional area of the rotor 112 whose cross-sectional surface is a surface including the long axis LX and the columnar axis CX are substantially the same. may

For example, the cross-sectional shape SS of the rotor 112 is such that the first apex TP1 and the second apex TP2 are divided into a pair of first arcs CA1 extending from the first apex TP1 and a pair of second arcs CA2 extending from the second apex TP2. , and a pair of parallel straight lines SL extending between the pair of first circular arcs CA1 and the pair of second circular arcs CA2.

For example, the diameter of each arc of the pair of first arcs CA1 and the pair of second arcs CA2 may be larger than the duct diameter DD.

Valve. Like G, for example, in the cross-sectional shape SS of the rotor 112, the ratio of the length of the minor axis SX to the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is 20/49.6. It may be below.
Valve. Like H, for example, in the cross-sectional shape SS of the rotor 112, the ratio of the length of the minor axis SX to the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is 15/49.6. It may be below.
Valve. I, for example, in the cross-sectional shape SS of the rotor 112, the ratio of the length of the minor axis SX to the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is 10/49.6. It may be below.
Valve. Like J, for example, in the cross-sectional shape SS of the rotor 112, the ratio of the length of the minor axis SX to the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is 5/49.6. It may be below.
In FIG. 13, "diameter" indicates the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2, and "width" indicates the length of the minor axis SX in the cross-sectional shape SS of the rotor 112. indicate

(Action and effect)
According to this embodiment, the cross-sectional shape SS of the rotor 112 is a shape in which a pair of apexes aligned along the long axis LX are sharp, so the time during which the rotor 112 blocks the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can suppress distortion of sound pressure.
Note that the sound pressure generator 101 can generate a large sound pressure if the distortion of the sound pressure can be suppressed.

Further, according to the example of the present embodiment, since the cross-sectional shape SS of the rotor 112 is symmetrical about the long axis LX, the sound pressure generator 101 can further suppress distortion of sound pressure.

Further, according to one example of the present embodiment, since the cross-sectional shape SS of the rotor 112 is a shape in which the first top portion TP1 and the second top portion TP2 have a curvature and are pointed, the sound pressure generating device 101 improve the health of

According to one example of this embodiment, the cross-sectional shape SS of the rotor 112 defines a first apex TP1 and a second apex TP2, a pair of first arcs CA1 extending from the first apex TP1, and a pair of arcs CA1 extending from the second apex TP2. It has a shape connected by a pair of second arcs CA2 and a pair of parallel straight lines SL extending between the pair of first arcs CA1 and the pair of second arcs CA2.
Therefore, the rotor 112 can be made thin so that the bulge of the cross-sectional shape SS of the rotor 112 toward the short axis SX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

Further, according to one example of the present embodiment, the cross-sectional shape SS of the rotor 112 has a shape connected by a pair of first circular arcs CA1, a pair of second circular arcs CA2, and a pair of parallel straight lines SL. , it has a portion composed of curved lines and a portion composed of parallel lines.
Since the cross-sectional shape SS of the rotor 112 has a curved portion, it is possible to suppress harmonics of the sound pressure, as in the first embodiment.
On the other hand, since the cross-sectional shape SS of the rotor 112 has a portion composed of parallel lines, it is possible to provide a moment (instantaneous opening) at which the opening area of the flow path A11 by the rotor 112 suddenly expands. As a result, the shoulders of the peaks of the generated sound pressure waveform can be dropped (the peaks of the waveform can be sharpened), and the sound pressure can be made closer to a sine wave. Note that the rotational position of the rotor 112 at the moment when the opening area of the flow path A11 suddenly expands is the position where the long axis LX is parallel to the inner wall 11W.
Therefore, the waveform of the sound pressure generated by the rotor 112 is improved so as to approach a sine wave.
If the waveform of the sound pressure generated by the rotor 112 can be approximated to a sine wave, the sound pressure generator 101 can generate a large sound pressure.

Further, according to the example of the present embodiment, the waveform of the sound pressure generated by the sound pressure generator 101 can be improved so as to be closer to a sine wave than the sound pressure generator 1 of the first embodiment. .
For example, as shown in FIG. 14, in the waveform of the sound pressure generated by the sound pressure generator 101, even in the RG3 region where the rotor 112 closes the flow path A11, the sound pressure generated by the sound pressure generator 101 is shows a waveform close to a sine wave.
As a result, the waveform of the sound pressure generated by the sound pressure generator 101 exhibits a waveform close to a sine wave over the entire state from the state in which the rotor 112 opens the flow path A11 to the state in which it closes.

For example, as shown in FIG. 15, among the frequency components of the sound pressure generated by the sound pressure generator 101, the primary component is the Valve. Compared with the case of F, it is slightly increased. It is considered that this depends on the expansion of the passing area when the rotor 112 is fully opened with respect to the flow path A11.
On the other hand, among the frequency components of the sound pressure generated by the sound pressure generator 101, the secondary component tends to gradually decrease as the thickness of the rotor 112 decreases.
Of the frequency components of the sound pressure generated by the sound pressure generator 101, the tertiary component and the quaternary component are the Valve. Compared to F, it is the same or lower.
As a result, the rotor 112 in which the primary component is high and the secondary component is low is effective as a rotor for generating sound pressure having a waveform close to a sine wave.

Further, according to one example of this embodiment, the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is larger than the duct diameter DD.
Therefore, the rotor 112 can be made thin so that the bulge in the cross-sectional shape SS of the rotor 112 in the direction intersecting with the long axis LX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

Further, according to one example of the present embodiment, in the cross-sectional shape SS of the rotor 112, the ratio of the length of the minor axis SX to the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is 20. /49.6 or less.
Furthermore, according to one example of the present embodiment, in the cross-sectional shape SS of the rotor 112, the ratio of the length of the minor axis SX to the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is 15 /49.6 or less.
Furthermore, according to one example of the present embodiment, in the cross-sectional shape SS of the rotor 112, the ratio of the length of the minor axis SX to the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is 10 /49.6 or less.
Furthermore, according to one example of the present embodiment, in the cross-sectional shape SS of the rotor 112, the ratio of the length of the minor axis SX to the diameter of each of the pair of first arcs CA1 and the pair of second arcs CA2 is 5 /49.6 or less.
Therefore, the rotor 112 can be made thin so that the bulge of the cross-sectional shape SS of the rotor 112 toward the short axis SX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

Further, according to one example of the present embodiment, the rotor 112 has a cross-sectional area of the flow path A11 whose cutting surface is a plane perpendicular to the pipe axis direction DT, and a surface including the long axis LX and the columnar axis CX. is approximately the same as the cross-sectional area of
Therefore, the rotor 112 can temporarily close the flow path A11.
Therefore, the sound pressure generator 101 can generate a large sound pressure.

<Modification>
In one example of each of the above-described embodiments, the test facility 9 includes, as the pipe 2, a straight pipe extending from the sound pressure generators 1, 101 into the combustor 7. may be provided with any plumbing as long as it extends to
As a modification, as shown in FIG. 16, a test equipment 9a, which is a modification of the test equipment 9, extends from the sound pressure generators 1 and 101 into the combustor 7 as a pipe 2a instead of the pipe 2, and combusts. A bent tube extending into the vessel 7 may be provided with a distal end bent toward the acoustic device 6 .

Although embodiments of the present disclosure have been described above, these embodiments are presented as examples and are not intended to limit the scope of the disclosure. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the gist of the disclosure. These embodiments and variations thereof are included within the scope and spirit of the disclosure.

<Appendix>
For example, the sound pressure generators 1 and 101 described in the above embodiments are understood as follows.

(1) The sound pressure generators 1 and 101 according to the first aspect include a tube portion 11 having a flow path A11 extending in the tube axis direction DT, and a Rotors 12 and 112 having a columnar shape with an extending columnar axis CX and capable of generating sound pressure by rotation about the columnar axis CX; a drive unit 13 for rotating the rotors 12 and 112; and the cross-sectional shape SS of the rotors 12 and 112 crossing the column axis CX has a sharp first top portion TP1, a sharp second top portion TP2, and the first top portion TP1 and the second top portion TP2. and a long axis LX aligned with .

According to this aspect, since the cross-sectional shape SS of the rotors 12 and 112 is a shape in which a pair of apexes aligned with the long axis LX are pointed, the time during which the rotors 12 and 112 block the flow path A11 can be shortened. can be done.
Therefore, the sound pressure generators 1 and 101 can suppress sound pressure distortion.

(2) The sound pressure generators 1 and 101 according to the second aspect are the sound pressure generators 1 and 101 of (1) in which the cross-sectional shape SS is symmetrical about the long axis LX.

According to this aspect, the sound pressure generators 1 and 101 can further suppress distortion of the sound pressure.

(3) In the sound pressure generator 1, 101 according to the third aspect, in the cross-sectional shape SS, the first top portion TP1 and the second top portion TP2 have a curvature and are pointed (1) or It is the sound pressure generator 1, 101 of (2).

According to this aspect, soundness of the sound pressure generators 1 and 101 is improved.

(4) In the sound pressure generator 1 according to the fourth aspect, the cross-sectional shape SS has a shape in which the first top portion TP1 and the second top portion TP2 are connected by a pair of arcs CA (1) or It is the sound pressure generator 1 of (2).

According to this aspect, since the cross-sectional shape SS is a shape in which circles are overlapped, the rotor 12 can be configured in a simple shape.
Therefore, it is easy to design and manufacture the rotor 12 .

(5) In the sound pressure generator 1 according to the fifth aspect, the flow path A11 has a duct diameter DD in a direction orthogonal to the column axis CX, and the diameter of each arc CA of the pair of arcs CA is , the sound pressure generator 1 of (4) larger than the duct diameter DD.

According to this aspect, the rotor 12 can be made thin so that the bulge in the cross-sectional shape SS in the direction intersecting with the long axis LX is reduced.
As a result, the time during which the rotor 12 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 1 can further suppress distortion of sound pressure.

(6) In the sound pressure generator 1 according to the sixth aspect, the cross-sectional shape SS has a short axis SX orthogonal to the long axis LX, and the short axis SX of the pair of arcs CA with respect to the diameter of each arc CA. The sound pressure generator 1 according to (4) or (5), wherein the length ratio of the shaft SX is 40/49.6 or less.

According to this aspect, the rotor 12 can be made thin so that the bulge of the cross-sectional shape SS toward the short axis SX is reduced.
As a result, the time during which the rotor 12 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 1 can further suppress distortion of sound pressure.

(7) A sound pressure generator 1 according to a seventh aspect is the sound pressure generator 1 of (6), wherein the ratio is 30/49.6 or less.

According to this aspect, the rotor 12 can be made thin so that the bulge of the cross-sectional shape SS toward the short axis SX is reduced.
As a result, the time during which the rotor 12 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 1 can further suppress distortion of sound pressure.

(8) A sound pressure generator 1 according to an eighth aspect is the sound pressure generator 1 of (6), wherein the ratio is 20/49.6 or less.

According to this aspect, the rotor 12 can be made thin so that the bulge of the cross-sectional shape SS toward the short axis SX is reduced.
As a result, the time during which the rotor 12 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 1 can further suppress distortion of sound pressure.

(9) In the sound pressure generating device 101 according to the ninth aspect, the cross-sectional shape SS is such that the first apex TP1 and the second apex TP2 form a pair of first circular arcs CA1 extending from the first apex TP1. , a pair of second arcs CA2 extending from the second top portion TP2, and a pair of parallel straight lines SL extending between the pair of first arcs CA1 and the pair of second arcs CA2. A sound pressure generator 101 according to any one of (1) to (3).

According to this aspect, the rotor 112 can be made thin so that the bulge of the cross-sectional shape SS toward the short axis SX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

(10) In the sound pressure generator 101 according to the tenth aspect, the flow path A11 has a duct diameter DD in a direction orthogonal to the column axis CX, and the pair of first arcs CA1 and the pair of second In the sound pressure generator 101 (9), the diameter of each arc of the two arcs CA2 is larger than the duct diameter DD.

According to this aspect, the rotor 112 can be made thin so that the bulge in the cross-sectional shape SS of the rotor 112 in the direction intersecting with the long axis LX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

(11) In the sound pressure generator 101 according to the eleventh aspect, the cross-sectional shape SS has a short axis SX orthogonal to the long axis LX, and the pair of first circular arcs CA1 and the pair of second circular arcs The sound pressure generator 101 according to (9) or (10), wherein the ratio of the length of the minor axis SX to the diameter of each arc of CA2 is 20/49.6 or less.

According to this aspect, the rotor 112 can be made thin so that the bulge of the cross-sectional shape SS toward the short axis SX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

(12) A sound pressure generator 101 according to a twelfth aspect is the sound pressure generator 101 of (11), wherein the ratio is 15/49.6 or less.

According to this aspect, the rotor 112 can be made thin so that the bulge of the cross-sectional shape SS toward the short axis SX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

(13) A sound pressure generator 101 according to a thirteenth aspect is the sound pressure generator 101 of (12), wherein the ratio is 10/49.6 or less.

According to this aspect, the rotor 112 can be made thin so that the bulge of the cross-sectional shape SS toward the short axis SX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

(14) A sound pressure generator 101 according to a fourteenth aspect is the sound pressure generator 101 of (13), wherein the ratio is 5/49.6 or less.

According to this aspect, the rotor 112 can be made thin so that the bulge of the cross-sectional shape SS toward the short axis SX is reduced.
As a result, the time during which the rotor 112 interrupts the flow path A11 can be shortened.
Therefore, the sound pressure generator 101 can further suppress distortion of sound pressure.

(15) The sound pressure generators 1 and 101 according to the fifteenth aspect have the cross-sectional area of the flow path A11 whose cut surface is perpendicular to the tube axial direction DT, the long axis LX, and the columnar axis CX. The sound pressure generator 1, 101 according to any one of (1) to (14), in which the cross-sectional area of the rotor 12, 112 having a cut surface including a is substantially the same.

According to this aspect, the rotors 12 and 112 can temporarily close the flow path A11.
Therefore, the sound pressure generators 1 and 101 can generate a large sound pressure.

1 sound pressure generator 2 pipe 2a pipe 3 air source 4 test lid 6 acoustic device 7 combustor 8 gas turbine 9 test facility 11 pipe section 11W inner wall 12 rotor 13 drive section 101 sound pressure generator 112 rotor A11 flow path AIR Air CA Arc CA1 First arc CA2 Second arc CX Column axis DD Duct diameter DT Tube axis direction LX Long axis SL Straight line SS Cross-sectional shape SX Minor axis TP1 First top TP2 Second top

Claims (15)

a tube portion having a flow path extending in the tube axis direction;
a rotor having a columnar shape having a columnar axis extending in a direction intersecting with the pipe axis direction in the flow channel and capable of generating sound pressure by rotation about the columnar axis;
and a drive unit that rotates the rotor,
A cross-sectional shape of the rotor that intersects the column axis has a sharp first apex, a sharp second apex, and a long axis along which the first apex and the second apex are aligned. Device. 2. The sound pressure generator according to claim 1, wherein said cross-sectional shape is symmetrical about said major axis. 3. The sound pressure generator according to claim 1, wherein in the cross-sectional shape, the first apex and the second apex have a curvature and are pointed. The sound pressure generator according to any one of claims 1 to 3, wherein the cross-sectional shape has a shape in which the first top portion and the second top portion are connected by a pair of arcs. the flow path has a duct diameter in a direction orthogonal to the column axis,
5. The sound pressure generator according to claim 4, wherein the diameter of each arc of said pair of arcs is larger than the diameter of said duct. the cross-sectional shape has a short axis orthogonal to the long axis;
6. The sound pressure generator according to claim 4, wherein the ratio of the length of the minor axis to the diameter of each arc of the pair of arcs is 40/49.6 or less. 7. The sound pressure generator according to claim 6, wherein said ratio is 30/49.6 or less. 8. The sound pressure generator according to claim 7, wherein said ratio is 20/49.6 or less. The cross-sectional shape defines the first apex and the second apex as a pair of first arcs extending from the first apex, a pair of second arcs extending from the second apex, and a pair of first arcs. The sound pressure generator according to any one of claims 1 to 3, having a shape connected by a pair of parallel straight lines extending between the pair of second circular arcs. the flow path has a duct diameter in a direction orthogonal to the column axis,
10. The sound pressure generator according to claim 9, wherein the diameter of each of said pair of first arcs and said pair of second arcs is larger than the diameter of said duct. the cross-sectional shape has a short axis orthogonal to the long axis;
11. The sound pressure generator according to claim 9, wherein the ratio of the length of the minor axis to the diameter of each of the pair of first arcs and the pair of second arcs is 20/49.6 or less. 12. The sound pressure generator according to claim 11, wherein said ratio is 15/49.6 or less. 13. The sound pressure generator according to claim 12, wherein said ratio is 10/49.6 or less. 14. The sound pressure generator according to claim 13, wherein said ratio is 5/49.6 or less. 2. A cross-sectional area of the flow path cut along a plane orthogonal to the direction of the tube axis and a cross-sectional area of the rotor cut along a plane including the long axis and the columnar axis are substantially the same. 15. The sound pressure generator according to any one of 14.

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