JP7033827B2 - Head structure of moving body - Google Patents

Description

The present invention relates to a head structure of a moving body having a micro pressure wave reducing performance capable of reducing a micro pressure wave generated when the moving body rushes into a tunnel.

When a train rushes into a tunnel at high speed, a compressed wave is generated in the tunnel. This compressed wave propagates in the tunnel at the speed of sound and is end-reflected at the exit. The pulsed pressure wave radiated outside the tunnel during this reflection is called a tunnel micropressure wave or simply a micropressure wave. Micro-pressure waves cause blasting noise, vibration of houses, rattling, and noise, so it is necessary to take measures. Since the micro-pressure wave is almost proportional to the maximum value of the pressure gradient (time change rate of the compression wave) of the compression wave arriving at the tunnel exit, it is effective to lengthen the formation time of the compression wave to smooth the pressure gradient. Will be. In the actual Shinkansen (registered trademark), measures such as extension / optimization of the train head and installation / extension of shock absorbers are taken.

In the conventional head portion shape S'shown in FIG. 7, the cross-sectional area change rate of the head portion tip 105a of the vehicle 102 is large, the cross-sectional area change rate is constantly increased at the head portion 105A of the vehicle 102, and the tail portion of the vehicle 102. At 105B, the cross-sectional area change rate is constant. Conventionally, it has been considered that the shape of the head portion for reducing the micro-pressure wave is preferably a shape in which the cross-sectional area change rate is constant except for the train tip portion as shown in FIG. 7 (see, for example, Non-Patent Document 1). This policy is reflected in the shape of the head of the current Shinkansen train. Such a conventional head portion shape for reducing micro-pressure waves is obtained by optimizing the head portion shape expressed by a small number of design parameters. In the head shape for reducing micro-pressure waves, it has been proposed to make the maximum pressure gradient value non-dimensional in consideration of the length of the train head based on acoustic theory, and the reciprocal of this maximum pressure gradient value is defined as efficiency. (See, for example, Non-Patent Document 2).

Masanobu Iida, 4 others, "Optimization of train head shape for reducing tunnel micro-pressure waves", JSME Proceedings B, 1996, Vol. 62, p.1428-1435

Miyachi, T., M.Fukuda, T., Arai, T., "Nondimensional maximum pressure gradient of tunnel compression waves generated by offset running axisymmetric trains", Journal of Wind Engineering and Industrial Aerodynamics <http://www.sciencedirect. com / science / article / pii / S0167610515301525>

It is shown in Non-Patent Document 2 that the efficiency of such a conventional head portion shape for reducing micro-pressure waves is about 0.8. Since the maximum value of this efficiency is 1 in the case of the ideal head shape, it was pointed out that there may be a head shape that has a higher effect of reducing micro-pressure waves.

An object of the present invention is to provide a head structure of a moving body capable of further improving the effect of reducing micro-pressure waves.

The present invention solves the above-mentioned problems by means of solutions as described below.
Although the description will be given with reference numerals corresponding to the embodiments of the present invention, the present invention is not limited to this embodiment.
As shown in FIGS. 1 to 3 and 6, the invention of claim 1 has a movement having a micro-pressure wave reducing performance capable of reducing a micro-pressure wave generated when a moving body (2) enters a tunnel. In the head portion structure of the body, the head portion shape (S) of the moving body has at least three peaks (P ₁ ) in the cross-sectional area change rate distribution (dA ^* / dX) of the head portion (5A) of the moving body. ~ P ₃ ), and there are large peaks (P ₁ , P ₃ ) of the cross-sectional area change rate distribution at the tip end (5a) and the rear end (5c) of the front end of the moving body, and this movement. There is a small peak (P ₂ ) of the cross-sectional area change rate distribution in the middle part (5b) of the head part of the body, and the peak (P ₁ ) of the cross-sectional area change rate distribution at the tip part of the head part of the moving body . Almost in the middle of the peak (P ₃ ) of the cross-sectional area change rate distribution at the rear end of the head portion, there is a peak (P ₂ ) of the cross-sectional area change rate distribution at the middle portion of this head portion. The width of the peak (P ₁ , P ₃ ) of the cross-sectional area change rate distribution at the front end and the rear end of the body is narrow, and the peak (P ₂ ) of the cross-sectional area change rate distribution at the middle of the front end It is a head structure (6) of a moving body characterized by having a wide width .

According to the second aspect of the present invention, in the head structure of the moving body according to the first aspect, as shown in FIG. 2, the shape of the head portion of the moving body is the rear end portion (5c) of the head portion of the moving body. It is a head structure of a moving body characterized in that the cross-sectional area change rate distribution (dA ^* / dX) is zero.

In the invention of claim 3, in the head structure of the moving body according to claim 1 or 2 , as shown in FIGS. 1 and 2, the head portion shape of the moving body is the head portion of the moving body. When the length (ln) of is less than 20 _m , the head structure of the moving body is characterized by having three peaks (P ₁ to P ₃ ) in the cross-sectional area change rate distribution of the head of the moving body. Is.

According to a fourth aspect of the present invention, in the head portion structure of the moving body according to claim 1 or 2 , as shown in FIG. 3, the head portion shape of the moving body is the length of the head portion of the moving body. When (ln) is 20 _m or more, the head structure of the moving body is characterized by having four or more peaks (P ₁ to P ₄ ) in the cross-sectional area change rate distribution at the head of the moving body. be.

According to the present invention, the effect of reducing micro-pressure waves can be further improved.

It is a side view of the head part structure of the moving body which concerns on 1st Embodiment of this invention, (A) is the side view which shows typically the case where the head part shape is smooth, (B) is the head part. It is a graph which shows typically the cross-sectional area change rate distribution of a part shape as an example. It is a side view of the head part structure of the moving body which concerns on 2nd Embodiment of this invention, and (A) shows typically the case where the head part shape smoothly connects the head part rear end with the tail part tip, as an example. It is a side view, and (B) is a graph schematically showing the cross-sectional area change rate distribution of the head portion shape as an example. It is a side view of the head part structure of the moving body which concerns on 3rd Embodiment of this invention, (A) is the side view which shows typically the case where the head part shape is smooth, and (B) is the head part. It is a side view schematically showing the case where the part shape smoothly connects the rear end of the head portion with the tip of the tail portion as an example. It is a side view of the head part structure of the moving body which concerns on Example and the prior art of this invention. It is a graph which shows the cross-sectional area change rate distribution in the head part structure of the moving body which concerns on Example and the prior art of this invention as an example. It is a graph which shows the pressure gradient waveform in the head part structure of the moving body which concerns on Example and the prior art of this invention as an example. It is a side view which shows typically the structure of the head part of the conventional moving body as an example.

(First Embodiment)
Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings.
The track 1 shown in FIG. 1 (A) is a passage (railway) on which the vehicle 2 travels. The track 1 includes a pair of rails that support and guide the wheels of the vehicle 2. The vehicle 2 is a moving body that moves along the track 1. Vehicle 2 is, for example, a high-speed train such as a railroad vehicle traveling on the Shinkansen (registered trademark) at a high speed of 300 km / h or more. The vehicle 2 shown in FIG. 1A is, for example, a leading vehicle when traveling in the direction of the arrow in the figure, and a trailing vehicle when traveling in the direction opposite to the arrow direction. The vehicle 2 includes a bogie 3, a vehicle body 4, and the like. The bogie 3 is a device that supports the vehicle body 4 and travels on the track 1. The vehicle body 4 is a structure for transporting loads such as crew members and passengers. The vehicle body 4 includes a front portion 5A and a tail portion 5B. In the vehicle body 4, the crew room on which the crew who operates the master controller for driving and controlling the vehicle 2 rides is arranged on the front portion 5A side, and the passenger cabin on which the passengers ride is arranged on the tail portion 5B side. ..

The head portion 5A is a portion constituting the front side of the vehicle 2. The head portion 5A is formed in a long streamline in order to reduce air resistance and micro-pressure waves. The head portion 5A includes a head portion tip 5a constituting the front portion of the head portion 5A, a head portion middle 5b forming an intermediate portion between the head portion tip 5a and the head portion rear end 5c, and a head portion intermediate 5b. It is provided with a front end rear end 5c and the like that constitute the rear portion of the 5A.

The tail portion 5B is a portion constituting the rear side of the vehicle 2. The tail portion 5B has a substantially constant cross-sectional area when cut on a vertical plane orthogonal to the center line of the vehicle 2. The tail portion 5B includes a tail portion tip 5d connected to the front end rear end 5c, a tail portion rear end 5e which is an end opposite to the tail portion tip 5d, and the like. The tail portion 5B is provided with a connecting device or the like for connecting other rolling stock, which is composed as an intermediate vehicle during formation, at the rear end portion 5e of the tail portion.

The head structure 6 is a structure having a micro-pressure wave reducing performance capable of reducing a micro-pressure wave generated when the vehicle 2 rushes into the tunnel. In the head portion structure 6, the head portion shape S is optimized on the premise that the cross-sectional area change rate has a plurality of peaks. The head portion structure 6 is formed in a smooth head portion shape S so that the flow around the head portion 5A does not greatly separate at the sudden change portion of the cross-sectional area.

The head portion shape S is a cross-sectional shape when cut on a vertical plane passing through the center line of the vehicle 2. The head portion shape S shown in FIG. 1A expresses the cross-sectional area change rate by a combination of a predetermined number (for example, 10) of error functions _, and the magnitudes of the peaks P1 to P3 of the cross _- sectional area change rate. , Position and spread are optimized as optimal parameters. The head portion shape S has at least three peaks P ₁ to P ₃ in the cross-sectional area change rate distribution of the head portion 5A of the vehicle 2. The head portion shape S is a smooth shape in which the cross-sectional area change rate is represented by a combination of error functions. Here, the cross-sectional area change rate is a rate at which the cross-sectional area when cut on a vertical plane orthogonal to the center line of the vehicle 2 changes from the front end 5a to the tail rear end 5e. The cross-sectional area change rate distribution dA ^* / dX shown in FIG. 1 is given based on 10 error functions, and is optimized with the size, position, and spread of each basis as parameters.

As shown in FIG. _1A , the head portion shape S has peaks P1 to P3 of cross _- sectional area change rate distribution dA ^* / dX at the head portion tip 5a, the head portion middle 5b, and the head portion rear end 5c. .. The head portion shape S is a shape that increases the cross-sectional area by about 1/3 at the front end portion 5a, the head portion middle 5b, and the head portion rear end 5c. The head portion shape S has a single large peak P ₁ and P ₃ with a cross-sectional area change rate dA / dX at the front end portion 5a and the head portion rear end 5c, and has a small and wide peak P ₂ at the head portion middle 5b. It is approximately W-shaped. The head portion shape S has three peaks P ₁ to P ₃ in the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A when the length l _n of the head portion 5A is less than 20 m.

The head structure of the moving body according to the first embodiment of the present invention has the effects as described below.
(1) In this first embodiment, there is a head portion shape S having at least three peaks P ₁ to P ₃ in the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A of the vehicle 2. Further, in the _first embodiment _, the head portion shape S having peaks P1 to P3 of the cross-sectional area change rate distribution dA ^* / dX at the head portion tip 5a, the head portion middle 5b, and the head portion rear end 5c of the vehicle 2. Is. Therefore, it is possible to disperse the peak of the maximum pressure gradient value in the tunnel by forming a substantially W-shaped head portion shape S having three peaks P ₁ to P ₃ in the cross-sectional area change rate distribution dA ^* / dX. It can reduce micro-pressure waves.

(2) In this first embodiment, when the length l _n of the head portion 5A of the vehicle 2 is less than 20 m, the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A of the vehicle 2 has three peaks P. It is a head portion shape S having ₁ to P ₃ . Therefore, the peak value of the pressure gradient waveform in the tunnel can be reduced.

(Second Embodiment)
In the following, the same parts as those shown in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.
In the head structure 6 shown in FIG. 2A, the front end 5c is smoothly connected to the tail tip 5d so that the flow around the head 5A does not separate significantly at the head rear end 5c. It is formed in a partial shape S. The head portion shape S has a cross-sectional area change rate dA / by a combination of a predetermined number (for example, 10) of error functions and a weight function indicating that the head portion rear end 5c is smoothly connected to the tail tip 5d. It expresses dX and is optimized with the magnitude, position _, and spread of peaks P1 to P3 of the cross _- sectional area change rate dA / dX as the optimum parameters. In the head portion shape S, the cross-sectional area change rate distribution dA ^* / dX at the head portion rear end 5c is zero. In the head portion shape S shown in FIG. 1 (A), the cross-sectional area change rate dA / dX becomes discontinuous at the connection portion between the tail portion tip 5d and the front end rear end 5c where the cross-sectional area of the vehicle body 4 becomes constant, and the flow flows. There is concern about the effects of peeling. In the head portion shape S shown in FIG. 2A, the front end rear end 5c is the tail tip 5d at the connection portion between the tail tip 5d and the front rear end 5c where the cross-sectional area of the vehicle body 4 is constant. It is rounded so that it connects smoothly with. The head portion shape S is optimized by multiplying the rear end of the head portion 5A by a cos-type weight function, and the cross-sectional area change rate dA of the head portion rear end 5c is optimized by the cos-type weight function. / dX becomes zero smoothly.

The head portion shape S shown in FIG. 2A has peaks P1 to P3 in the cross _- sectional area change rate distribution dA ^* / dX at the head portion tip 5a _, the head portion middle 5b, and the head portion rear end 5c. The head portion shape S has three peaks P ₁ to P ₃ in the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A when the length l _n of the head portion 5A is less than 20 m.

The head structure of the moving body according to the second embodiment of the present invention has the effects described below in addition to the effects of the first embodiment.
In this second embodiment, the front portion shape S is such that the cross-sectional area change rate distribution dA ^* / dX at the front end rear end 5c of the vehicle 2 is zero. Therefore, it is possible to suppress the separation of the flow at the connection portion between the rear end portion 5d of the tail portion and the rear end portion 5c of the front portion where the cross-sectional area of the vehicle body 4 becomes constant.

(Third Embodiment)
The vehicle body 4 shown in FIG. 3 includes a long head portion 5A having a length l _n of the head portion 5A of the vehicle 2 of 20 m or more. The head portion structure 6 shown in FIG. 3 (A) is formed into a smooth head portion shape S similar to the head portion structure 6 shown in FIG. 1 (A). The head structure 6 shown in FIG. 3B is formed in a head shape S in which the rear end 5c of the head is smoothly connected to the tip 5d of the tail, similarly to the head structure 6 shown in FIG. 2A. ing. When the length l _n of the head portion 5A of the vehicle 2 is 20 m or more, the head portion shape S has four peaks P ₁ to P ₄ in the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A of the vehicle 2. There is. This third embodiment has the same effect as that of the first embodiment and the second embodiment.

The graph shown in FIG. 4 is a graph showing the shape of the head portion according to Examples 1 and 2 and the conventional example as an example. The vertical axis shown in FIG. 4 is the shape, and the horizontal axis is the distance from the tip of the head portion. The graph shown in FIG. 5 is a graph showing the cross-sectional area change rate distribution dA ^* / dX of the head portion shape according to Examples 1 and 2 and the conventional example as an example. The vertical axis shown in FIG. 5 is the cross-sectional area change rate dA / dX, and the horizontal axis is the distance from the tip of the head portion. Example 1 shown in FIGS. 4 and 5 corresponds to the head portion shape S according to the first embodiment shown in FIG. 1 (A), and the cross-sectional area change rate distribution dA having a length l _n = 12 m of the head portion 5A. ^* This is an example of / dX. Example 2 shown in FIGS. 4 and 5 is an example of the cross-sectional area change rate distribution dA ^* / dX corresponding to the head portion shape S according to the second embodiment shown in FIG. 2 (A). Examples 1 and 2 are examples of the cross-sectional area change rate distribution dA ^* / dX when the head portion shape S is optimized by Howe's acoustic theory. The conventional example shown in FIGS. 4 and 5 is an example of the cross-sectional area change rate dA / dX corresponding to the conventional head portion shape S'shown in FIG. 7.

The pressure gradient waveform calculated by Howe's acoustic theory is shown in FIG. The vertical axis shown in FIG. 6 is the pressure gradient ∂p / ∂t, and the horizontal axis is time. The peak of the pressure gradient waveform shown in FIG. 6 is proportional to the peak of the tunnel micropressure wave. As shown in FIG. 6, the pressure gradient waveforms of Examples 1 and 2 have more dispersed peaks than the pressure gradient waveforms of the conventional example, and the effect of reducing the micro-pressure wave was confirmed. Further, it was confirmed that the head portion shape having a plurality of peaks in the cross-sectional area change rate distribution dA ^* / dX as in Examples 1 and 2 is a head portion shape having a high effect of reducing micro-pressure waves.

(Other embodiments)
The present invention is not limited to the embodiments described above, and various modifications or modifications can be made as described below, and these are also within the scope of the present invention.
(1) In this embodiment, the case where the moving body is a railroad vehicle has been described as an example, but the present invention is not limited to this. For example, the present invention can be applied to various moving objects that plunge into a narrow space from a wide space, such as a magnetic levitation type railway, an automobile, an aircraft, or a flying object that travels at high speed. Further, in this embodiment, the case where the vehicle 2 is a Shinkansen train has been described as an example, but a conventional line train traveling on a conventional line or a new existing train capable of mutually traveling between a Shinkansen and a conventional line. The present invention can also be applied to trains for direct operation and the like. Further, in this embodiment, a tunnel has been described as an example as a structure, but a tunnel shock absorber covering the tunnel entrance in order to reduce the tunnel micro-pressure wave, an overpass over the track 1, and a track 1 on the track 1. The present invention can also be applied to structures such as Hashigami Station where a station bookstore is located.

(2) In the first embodiment and the second embodiment, the cross-sectional area at the front end 5c of the vehicle 2 is larger than the peak P ₁ of the cross-sectional area change rate distribution dA ^* / dX at the front end 5a of the vehicle 2. The case where the peak P ₃ of the rate of change distribution dA ^* / dX is smaller has been described as an example, but the present invention is not limited to this. For example, the cross-sectional area change rate distribution at the front end 5c of the vehicle 2 rather than the peaks P ₁ and P ₂ of the cross-sectional area change rate dA ^* / dX at the front end 5a and / or the front middle 5b of the vehicle 2. The present invention can also be applied to the case where the peak P ₃ of dA ^* / dX is made smaller. Further, in the third embodiment, when the length l _n of the head portion 5A of the vehicle 2 is 20 m or more, the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A of the vehicle 2 has four peaks P ₁ The case where there is ~ P ₄ has been described as an example, but the description is not limited to this. For example, when the length l _n of the head portion 5A of the vehicle 2 is 20 m or more, four or more peaks P ₁ , P ₂ , P in the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A of the vehicle 2. The present invention can be applied even when there are ₃ , P ₄ , ....

1 track 2 vehicle (moving body)
3 bogie 4 body 5A head 5B tail 5a head tip 5b head middle 5c head rear end 5d tail tip 5e tail rear end dA / dX cross-sectional area change rate dA ^* / dX cross-sectional area change rate distribution ∂p / ∂t Pressure gradient S Head shape P ₁ to P ₄ Peak

Claims (4)

It is a head structure of a moving body having a micro pressure wave reduction performance capable of reducing the micro pressure wave generated when the moving body rushes into a tunnel.
The shape of the head of the moving body is
There are at least three peaks in the cross-sectional area change rate distribution at the head of this moving body.
There is a large peak in the cross-sectional area change rate distribution at the tip of the front end and the rear end of the front end of the moving body, and there is a small peak in the cross-sectional area change rate distribution in the middle of the head of the moving body.
A break in the middle part of the head portion is approximately halfway between the peak of the cross-sectional area change rate distribution at the tip of the head portion of the moving body and the peak of the cross-sectional area change rate distribution at the rear end portion of the head portion. There is a peak in the area change rate distribution,
The width of the peak of the cross-sectional area change rate distribution at the front end and the rear end of the moving body is narrow, and the peak width of the cross-sectional area change rate distribution at the middle of the front end is wide.
The head structure of the moving body, which is characterized by. In the head structure of the moving body according to claim 1,
The shape of the head portion of the moving body is such that the cross-sectional area change rate distribution at the rear end portion of the head portion of the moving body is zero.
The head structure of the moving body, which is characterized by. In the head structure of the moving body according to claim 1 or 2.
The shape of the head portion of the moving body has three peaks in the cross-sectional area change rate distribution of the head portion of the moving body when the length of the head portion of the moving body is less than 20 m.
The head structure of the moving body, which is characterized by. In the head structure of the moving body according to claim 1 or 2.
The shape of the head portion of the moving body is such that when the length of the head portion of the moving body is 20 m or more, there are four or more peaks in the cross-sectional area change rate distribution of the head portion of the moving body.
The head structure of the moving body, which is characterized by.

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