JP3546149B2 - Basic shape type of centrifugal acceleration field generating structure - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a basic shape type of a centrifugal acceleration field generating structure.
[0002]
[Prior art]
Buildings, such as buildings, are built on the ground. A physical test of the ground can only be performed after the construction has been completed. 2. Description of the Related Art A centrifugal loading device that virtually generates a large gravitational field is used to perform a preliminary test on a test object such as a ground on which a large gravity acts. The centrifugal loading device has an axisymmetric rotating arm. A bucket for loading a test specimen and a bucket for placing a balance weight are axially symmetrically suspended from the rotating arm so as to be swingable.
[0003]
A centrifugal force equivalent to 100 G is applied to the specimen. The total weight of the rotating arm, both buckets, the vibration imparting device necessary for testing the test specimen, and other attached structures is huge. Care is taken to minimize the burden on the support structure including the bearing that supports such a huge rotating body.
[0004]
One means for reducing the burden is windage reduction means. Rotary bodies such as water turbines, wind turbines, marine propulsion rotor blades, and turbine blades have been studied to increase their thrust.However, research on windage reduction of rotors such as centrifugal loading devices has been studied. Not practically done.
[0005]
In a centrifugal loading device, it is important to reduce the windage loss. Furthermore, suppression of noise generation is desired.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a basic shape type of a centrifugal acceleration field generating structure in which windage reduction is effectively realized.
Another object of the present invention is to provide a basic shape type of a centrifugal acceleration field generating structure in which noise suppression is effective.
[0007]
[Means for Solving the Problems]
Means for solving the problem are expressed as follows. The technical matters corresponding to the claims in the expression are appended with numbers, symbols, etc. in parentheses (). The numbers, symbols, etc. clarify the correspondence / correspondence between the technical matter corresponding to the claim and the technical matter of at least one of a plurality of forms of implementation. It is not intended to show that technical matters are limited to technical matters of the embodiments.
[0008]
The basic shape type of the centrifugal acceleration field generating structure according to the present invention is a rotating beam (6, beam I in FIG. 3) having a substantially vertical axis of rotation (3) and having an outer contour formed in a substantially rectangular parallelepiped shape. ) And an upstream rectifier (26, 27) formed in the rotating beam, and the upstream rectifier (26, 27) forms a streamline that faces upward at the upper side and downward at the lower side. And is formed upstream with respect to the airflow received by the rotating beam (6).
[0009]
The rectifier on the upstream side, which receives the wind pressure directly, has a wind pressure resistance when removing air from the space occupied by the rotating beam (space on the disk), compared with that of the reference body (beam I type in FIG. 3). Smaller, less windage.
[0010]
Furthermore, it comprises a downstream rectifier (24, 25) formed in the rotating beam (6), and the lower rectifier (24, 25) faces downward on the upper side with respect to the airflow received by the rotating beam (6). Preferably, a streamline is formed on the lower side and pointing upward, and is formed on the downstream side with respect to the airflow received by the rotating beam (6). It is more preferable that the upstream rectifiers (26, 27) and the downstream rectifiers (25, 26) are arranged axially symmetrically, both statically and dynamically, in terms of fluid dynamics. The upstream and downstream wind pressures are substantially equalized, and the windage loss is reduced accordingly.
[0011]
The effect of reducing the windage loss by attaching an accessory to the end of the rotating beam (6) cannot be expected (see round plate 1, round 2, round 3, round 4, and FIG. 5).
[0012]
The effect of reducing the upstream rectifiers (26, 27) on the centrifugal side of the rotating beam (6) is greater than that on the centripetal side. It is presumed that it would be better not to have a straightening wing on the centripetal side (center side).
[0013]
It is also effective that the upstream rectifier (26, 27) is formed by a curved surface that continuously extends from the upper edge side to the lower edge side (beam II type). Even if such an upstream rectifier (26, 27) is not provided on the downstream side, the same effect can be obtained (beam II-1, type II in FIG. 3, table in FIG. 5).
[0014]
The basic shape type of the centrifugal acceleration field generating structure according to the present invention includes a rotating beam (6) having a substantially vertical rotation axis (3) and an outer contour formed in a substantially rectangular parallelepiped shape, and a rotating beam (6). 6) are formed on the rectifier (24, 25, 26 or 27), and the rectifiers (24, 25, 26 or 27) are arranged on the upper side and the lower side, and the rotation axis (3). Is formed by a thin flat blade (disc type I in FIG. 3) that extends upstream and downstream of the rotary beam (6) on a plane perpendicular to the axis of rotation, and with respect to the rotation axis (3). The fact that they are formed substantially symmetrically is particularly excellent (table in FIG. 5).
[0015]
It is particularly preferred that the wing plate is a disk centered on a point on the axis of rotation (disk I type). The distance on the plane between an arbitrary point on the contour of the vane plate and a point on the axis of rotation is indicated by R, and a straight line connecting the arbitrary point and a point on the axis of rotation (3). If the angle between the rotation line and the radial line of the rotating beam (6) is represented by θ (<90 degrees), the outline of the blade is formed by a shape line in which R decreases as θ increases. This is recommended from the experimental results (disc I-1, type 2, table in FIG. 5). This indicates that a larger rectifying area is better.
[0016]
The basic shape type of the centrifugal acceleration field generating structure according to the present invention includes a rotating beam (6) having a substantially vertical axis of rotation and having a substantially rectangular parallelepiped outer shape, and a rotating beam (6). The upstream rectifier is formed on the centrifugal side, and forms a streamline facing the centrifugal direction on the upstream side and the centripetal direction on the downstream side. Such a thing (bucket type in FIG. 3) also has a windage reduction effect.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Corresponding to the drawings, the embodiment of the basic shape type of the centrifugal acceleration field generating structure according to the present invention is provided with a rotation drive mechanism. The rotation drive mechanism includes a base 1 as shown in FIG. A rotating shaft 2 is rotatably supported by the base 1. A rotation axis 3 of the rotation shaft 2 is orthogonal to a horizontal plane corresponding to the ground 1FL. The rotating shaft 2 is connected to the main motor 5 via a reduction gearbox and a shaft coupling. A rotating table (rotating arm) 6 is coupled to the rotating shaft 2 via a key. The turntable 6 is formed by both left and right arms, and has a structure which is generally symmetrical with respect to the rotation axis 3 in design.
[0018]
The test specimen holder 7 and the balance weight holder 8 are arranged symmetrically with respect to the rotation axis 3, and are supported by the turntable 6 and are swingably suspended. The cage 7 for the test body and the cage 8 for the balance weight have a structure which is substantially symmetrical with respect to the rotation axis 3 in design. The holder 7 for the test specimen and the holder 8 for the balance weight are rotatably and swingably supported by suspension shafts 9 and 11, respectively. The suspension shafts 9 and 11 are parallel to each other horizontally and are fixed to the turntable 6.
[0019]
The centrifugal rotation mechanism formed by the turntable 6, the test specimen holder 7, and the balance weight holder 8 is disposed between the first floor floor 1FL and the first basement floor B1F. A space is provided between the lower surface of the turntable 6 and the floor B1F on the first basement level so that the worker can walk freely. Wind flows in the space between the first floor floor 1FL and the first basement floor floor B1F, generating noise.
[0020]
FIGS. 2A, 2B, 2C, and 2D are radial projections of the rotary table 6 when viewed from four angles. As shown in FIG. 2A, the turntable 6 has a generally hexahedral structure, is formed of six-sided walls, and has a rectangular parallelepiped structure that is long in one axis direction. The six surfaces are formed by upper and lower surfaces parallel to a horizontal plane, which is surfaces orthogonal to the rotation axis, front and rear surfaces orthogonal to the circumferential direction, and both side surfaces orthogonal to the radial direction.
[0021]
Of the front and rear surfaces orthogonal to the circumferential direction, the front surface 21 that receives wind pressure directly and is located forward in the rotation direction is generally closed. Of the front and rear surfaces orthogonal to the circumferential direction, a rear surface 22 which is located in the rear in the rotation direction without being directly subjected to wind pressure is opened at some places, and a plurality of windows 23 are opened. Such a window is opened to observe the swinging of the bucket and the movement of the specimen. Thus, the turntable 6 is not necessarily formed axially symmetric with respect to wind pressure resistance, that is, in terms of fluid dynamics.
[0022]
Four parts: a front part on the front side in the circumferential direction (upstream), a lower part on the front side (upstream) in the circumferential direction, a top part on the rear side in the circumferential direction (downstream), and a lower part on the rear side in the circumferential direction (downstream). The first rotor 24 (FIG. 2 (a)) and the second rotor are axially symmetrical and mirror-symmetric with respect to a plane including the rotation axis 3 and orthogonal to the direction in which these four parts face each other. 25 (FIG. 2A), a third rotor 26 (FIG. 2A), and a fourth rotor 27 (FIG. 2B) are detachably attached. The first rotor 24 and the second rotor 25 are arranged and mirror-symmetrical with respect to a horizontal plane (a plane orthogonal to the rotation axis 3). The third rotary blade 26 and the fourth rotary blade 27 are arranged and mirror-symmetrical with respect to the same horizontal plane. The first rotating blade 24, the second rotating blade 25, the third rotating blade 26, and the fourth rotating blade 27 are each arranged and shaped axially symmetrically.
[0023]
The first rotor 24, the second rotor 25, the third rotor 26, and the fourth rotor 27 are each formed in a quarter cylindrical surface. The downstream side of the quarter cylindrical surface of the first rotary blade 24 faces the center side (the side toward the symmetric reference mirror surface which is a horizontal plane). The downstream side of the quarter cylindrical surface of the second rotary blade 25 faces the center side. A quarter cylindrical surface of the third rotor 26 has its upstream side facing the center side. The upstream side of the quarter cylindrical surface of the fourth rotary blade 27 faces the center side.
[0024]
A large space is provided between the first rotor 24 and the second rotor 25 in the axial direction. In other words, the separation between the first rotor 24 and the second rotor 25 is sufficiently larger than the radius of their quarter cylindrical surfaces. A large space is provided in the axial direction between the third rotary blade 26 and the fourth rotary blade 27. In other words, the separation between the third rotor 26 and the fourth rotor 27 is sufficiently larger than the radius of their quarter cylindrical surfaces.
[0025]
In other words, the quarter cylindrical surface of the first rotor 24 and the second rotor 25 is combined into a half cylindrical surface by bringing the first rotor 24 and the second rotor 25 closer to each other. The quarter cylindrical surface of the third rotating blade 26 and the fourth rotating blade 27 is synthesized into a half cylindrical surface by bringing the third rotating blade 26 and the fourth rotating blade 27 closer to each other. . When there is no such space, the wind pressure and windage are greater than when there is such a space.
[0026]
The respective quarter cylindrical surfaces of the first rotor 24, the second rotor 25, the third rotor 26, and the fourth rotor 27 are substantially smooth on the above-described substantially upper and lower surfaces of the turntable 6. Connected. This smooth connection is of course favorable in terms of fluid dynamics.
[0027]
The downstream rotary blades 24 and 25 are formed smoothly in a direction in which the discharge streamlines approach each other, and the upstream rotary blades 26 and 27 are formed in a direction in which the suction streamlines move away from each other. It is preferable that the rotor is provided only near the upper and lower edges. Rotors with large areas, on the contrary, are not good because they diverge the streamlines greatly.
[0028]
FIG. 3 is a test flowchart created for the research and development of a low windage and low-noise turntable in "Development of a vibration test device under a high centrifugal acceleration field". The turntable to be tested is basically divided into four types. These four types are not classifications of the present invention, but are classification types for general test research.
[0029]
The first type, the beam I type, is a quadrangular prism and is not provided with roundness. The second type, beam type II, is generally a square prism, but is entirely rounded on the upstream and downstream sides (this is different from the embodiment shown in FIG. 2). The third type, the disk type, has a disk shape (flat cylinder). The bucket type, which is the fourth type, is provided with a bucket for placing a test body and a balance weight at the distal end.
[0030]
The beam I type is classified into three types: a beam I-1, a plate type, and a beam I-2. The beam I-1 is formed by forming a quarter cylindrical surface having a small curvature at the upper and lower corners on the upstream and downstream sides, which are the four corners excluding the side corners. Is similar to the embodiment. The beam I-2 has a base length of 0.980 times the reference length (the arm length of the beam I type is taken as the reference length) without considering roundness.
[0031]
The plate type is further classified into four types. The plate round type 1 is an airfoil in which a windbreak plate is attached to a portion closer to the outside of the above-described square portion. The plate round type 2 is an airfoil in which a windbreak plate is attached to a portion closer to the outside of the lower corner portion of the above-described square portions. The plate round type 3 has a windbreak plate disposed on the front and rear surfaces instead of the windbreak plate in the plate round type 1, but on the upper and lower surfaces. Plate round type 4 is provided with a windbreak plate on the entire upper and lower surfaces.
[0032]
Beam type II is classified into beam type II-1 and beam type II-2. The beam II-1 is obtained by increasing the curvature (radius) of the front and rear roundness. The beam II-2 is formed by limiting roundness to a radius portion.
[0033]
The disk type I is obtained by attaching a circular roof panel and a floor panel to a beam I type beam. Disk types are classified into disk I type and disk II type. Disk I type is classified into disk I-1 and disk type I and disk II type. The disks I-1 and I-2 and the disk II have modified distribution shapes of the roof plate and the floor plate in the circumferential direction. The diameter of the beam differs between the disk I-1 type and the disk I-2 type. The disk type II has a circular roof plate / floor plate missing in a certain angle range.
[0034]
A test was performed on such a classification type under the same conditions (number of rotations, load mass). FIG. 4 shows the results of comparative experiments on the basic types of the beam I type, the beam II type, the disk type, and the bucket type, which are classification types regarding the basic shape. Except for the bucket type, intuitive and self-evident results have been obtained for windage. FIG. 5 shows the data based on the basic form of the beam I type.
[0035]
However, the upper column of the data in FIG. 5 is a comparison value with the disk type. Among the beam types, the beam II type, that is, the embodiment of FIG. 2 is superior. Except for the disk type, as can be seen from the comparison with the basic type of the beam I type, the beam II type is overwhelmingly superior. What can be said about all is a sufficient condition that the roundness is superior to the non-rounded one.
[0036]
From such a table, it cannot be simply determined which is superior as the invention. The disk type is superior to other types, but has a drawback that the area and the weight are increased. Although the four plate types are almost the same, no improvement effect can be expected. The basic shape of the beam II is superior to the beams II-1 and II-2. Although such an analysis is possible, inventions that emphasize practicality are better for each type.
[0037]
The overall conclusion is a sufficient condition that it is excellent to provide as large a radius as possible on the front and rear edges (sides) where the area receiving the wind pressure is relatively small (the aspect ratio is large).
[0038]
Preferably, the rectifier is detachable from the basic beam from the viewpoint of manufacturing and maintenance. The rectifiers 24, 25, 26, 27 shown in FIG. 2 are lightweight and have an effective windage reduction effect.
[0039]
【The invention's effect】
The basic shape type of the centrifugal acceleration field generating structure according to the present invention has a windage reduction effect.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a name according to the present invention.
2 (a), 2 (b), 2 (c), 2 (d) are perspective projections of the rotary table of the embodiment of the present invention viewed from four different angles, respectively.
FIG. 3 is a test flowchart showing a basic type for performing a windage loss test in comparison with a basic beam which is a basic structure of a turntable.
FIG. 4 is a table showing test results.
FIG. 5 is another table showing test results.
[Explanation of symbols]
3: Rotating axis 6: Rotating beam (rotary table, beam I type)
24, 25 ... downstream rectifiers 26, 27 ... upstream rectifiers

Claims (6)

A rotating beam having a substantially vertical axis of rotation and an outer contour formed in a substantially rectangular parallelepiped shape,
An upstream rectifier formed in the rotating beam,
The upstream rectifier forms a streamline with its upstream side facing its center side ,
And a basic shape type of a centrifugal acceleration field generating structure formed on an upstream side with respect to an airflow received by the rotating beam. In claim 1,
Furthermore, it comprises a downstream rectifier formed in the rotating beam,
The lower downstream-side regulating member is provided with, characterized in that the rotating beam is downstream of it with respect to the airflow receiving forms a streamline facing the center side, and are formed on the downstream side with respect to the air flow which the rotating beam is subjected Basic shape type of centrifugal acceleration field generating structure. In claim 1,
The basic shape type of the centrifugal acceleration field generating structure, wherein the upstream rectifier is formed on an upper edge side of the rotating beam. In claim 1,
The basic shape type of a centrifugal acceleration field generating structure, wherein the upstream rectifier is formed on an upper edge side and a lower edge side of the rotary beam. In claim 3 or 4,
The basic shape type of a centrifugal acceleration field generating structure, wherein the upstream rectifier is formed on a centrifugal side of the rotating beam. In claim 1,
The basic shape type of a centrifugal acceleration field generating structure, wherein the upstream rectifier is formed of a curved surface that continuously extends from an upper edge to a lower edge.

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