Exhaust pipe position determination method

Abstract

To provide a method for determining the positions of exhaust pipes of a plurality of connected diesel cars, for suppressing pollution by soot in exhaust gas exhausted from the exhaust pipes.SOLUTION: A method for determining the positions of exhaust pipes 20 for performing exhausting from an engine 11 of a plurality of connected diesel cars 10 includes a step for determining the positions of the exhaust pipes 20 on the basis of a result of a wind tunnel test using a model simulating the diesel cars 10. In the determining step, the positions of the exhaust pipes 20 are determined on the basis of a dimensionless flow speed being a ratio of a speed of an air stream corresponding to travel wind around the model with respect to a speed of the travel wind simulated by the wind tunnel test that acts on the model.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for determining the location of an exhaust pipe from the engines of a multi-rail diesel railcar. [Background technology]

[0002] One type of railway vehicle is a diesel railcar that runs on a non-electrified section using an engine. In this type of diesel railcar, exhaust gas is discharged from the engine. The exhaust gas is discharged through an exhaust pipe. For example, the exhaust gas is guided by an exhaust pipe from under the floor where the engine is installed to near the roof of the vehicle, and then discharged (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-90116 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the soot in the exhaust gas discharged from the exhaust pipe can pollute the area behind the exhaust pipe. In particular, when multiple diesel railcars are coupled together, the pollution caused by the soot in the exhaust gas is significant.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a method for determining the position of an exhaust pipe which suppresses pollution caused by soot in the exhaust gas emitted from the exhaust pipes of multiple coupled diesel railcars. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a method for determining the position of an exhaust pipe exhausted from the engines of multiple coupled diesel railcars, which includes a step of determining the position of the exhaust pipe based on the results of a wind tunnel test using a model simulating the diesel railcar, and is characterized in that the step of determining the position of the exhaust pipe is based on a dimensionless flow velocity, which is the ratio of the air flow speed corresponding to the running wind around the model to the speed of the running wind acting on the model simulated in the wind tunnel test.

[0007] According to the present invention, since the position of the exhaust pipe is determined based on the dimensionless flow velocity in a wind tunnel test, it is possible to prevent the exhaust gas discharged from the exhaust pipe of a traveling diesel railcar from stagnating around the exhaust pipe, and therefore it is possible to prevent contamination by soot in the exhaust gas.

[0008] The determining step may determine a position of the exhaust outlet of the exhaust pipe at a position corresponding to a position at which the dimensionless flow velocity is equal to or greater than a threshold value in a wind tunnel test.

[0009] The threshold may be 0.6.

[0010] The method may further include a step of determining the threshold value based on at least one of an exhaust speed of exhaust from the exhaust pipe and a distance in a traveling direction from the exhaust pipe to a predetermined portion of the diesel railcar.

[0011] The exhaust pipe whose position is to be determined is provided at the connecting portion between the diesel railcars, extending upward from the underfloor portion, and the determining process may determine the height position of the exhaust outlet of the exhaust pipe and its position in the direction of the sleepers based on the dimensionless flow velocity above the portion corresponding to the connecting portion.

[0012] The coupling portion of the diesel railcars may be a coupling portion between end faces of the diesel railcars.

[0013] Each of the diesel railcars whose end faces are connected to each other may have a ceiling unit that forms an accommodation space and protrudes upwardly from the top surface of the end face side.

[0014] The accommodation space may accommodate a storage portion that stores compressed air.

[0015] The distance between the ceiling units of the diesel railcars whose end faces are connected to each other may be 2m or less.

[0016] The dimensionless flow velocity may be the ratio of the airflow velocity around the model measured in the wind tunnel to the airflow velocity along a predetermined direction corresponding to the traveling direction of the diesel railcar directed toward the model stationary in the wind tunnel. Effect of the Invention

[0017] According to the present invention, it is possible to suppress pollution due to soot in exhaust gas discharged from the exhaust pipes of multiple coupled diesel railcars. [Brief description of the drawings]

[0018] [Figure 1] 1 is an explanatory diagram showing an outline of an example of the configuration of a diesel railcar provided with an exhaust pipe whose position is to be determined by a method according to one embodiment of the present invention; [Diagram 2] 2 is a partially enlarged view of a surface of one of the diesel railcars in FIG. 1 facing the other diesel railcar. [Diagram 3] FIG. 13 is a diagram showing the results of a wind tunnel test. [Figure 4] FIG. 13 is a diagram showing the results of a wind tunnel test. [Diagram 5] FIG. 13 is a diagram showing the results of a wind tunnel test. [Figure 6] FIG. 11 is a diagram showing the correspondence between the results of a wind tunnel test and the results of an on-vehicle test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated description will be omitted.

[0020] <Railway vehicles> Fig. 1 is an explanatory diagram showing an outline of an example of the configuration of a diesel railcar on which an exhaust pipe to be positioned by a method according to one embodiment of the present invention is provided, and more specifically, an explanatory diagram showing an outline of an example of the configuration of a train including the above-mentioned diesel railcar. Fig. 2 is a partially enlarged view of a surface of one of the diesel railcars in Fig. 1 facing the other diesel railcar.

[0021] The train 1 in Fig. 1 is made up of a plurality of coupled diesel railcars 10, and in the example shown in the figure, two diesel railcars 10 are coupled together. More specifically, the train 1 in Fig. 1 is made up of two diesel railcars 10 coupled together at their end faces 10b, which are the faces opposite the driver's cab 10a. In the train 1 in Fig. 1, an aisle 2 is provided between the diesel railcars 10.

[0022] Each diesel railcar 10 is a railcar that runs on a railroad track (not shown) and includes an engine 11, which is a heat engine, as a power source for running the railcar. More specifically, the engine 11 drives wheels 13 of a bogie 12.

[0023] Each diesel railcar 10 is provided with bogies 12 on the cab 10a side and the end face 10b side. The engine 11 includes an engine 11A that drives the wheels of the bogies 12 on the end face 10b side. The engine 11 may also include an engine 11B that drives the wheels of the bogie 12 on the cab 10a side. The engine 11 is mounted under the floor of each diesel railcar 10, i.e., at the bottom of the car body 14.

[0024] Furthermore, each diesel railcar 10 has a ceiling unit 15 on the top surface of the car body 14. The ceiling unit 15 is a unit that forms an accommodation space K. The accommodation space K accommodates, for example, a storage section 16 that stores compressed air. The compressed air stored in the storage section 16 is used, for example, to tilt the diesel railcar 10 in a controlled natural pendulum manner.

[0025] At least one ceiling unit 15 is provided on the end face 10b side. For example, the distance between the ceiling units 15 on the end faces 10b sides of adjacent diesel railcars 10 is, for example, 2 m or less. There may be multiple ceiling units 15. In this case, for example, the compressed air storage unit 16 is accommodated in the accommodation space K only in the ceiling unit 15 on the end face 10b side, and in the other ceiling units 15, things other than the compressed air storage unit 16 (for example, an air conditioning unit) are accommodated in the accommodation space K.

[0026] Each diesel railcar 10 also has an exhaust pipe 20. The exhaust pipe 20 exhausts gas from the engine 11. Specifically, one end of the exhaust pipe 20 is connected to the engine 11, and exhaust gas from the engine 11 is discharged from the other end.

[0027] The exhaust pipe 20 includes an exhaust pipe 20A for the engine 11A. The exhaust pipe 20A has a horizontal exhaust pipe 21A and a vertical exhaust pipe 22A.

[0028] The horizontal exhaust pipe 21A guides exhaust gas from the engine 11A horizontally toward the end face 10b, and is provided to extend horizontally from the engine 11A located under the floor. One end of the horizontal exhaust pipe 21A is connected to the engine 11A, and the other end is connected to the lower end of the vertical exhaust pipe 22A. The other end of the horizontal exhaust pipe 21A is located outside the car body 14 in the running direction, i.e., the longitudinal direction of the car. In this specification, the "running direction" refers to the running direction of the train 1 and the diesel railcar 10.

[0029] The vertical exhaust pipe 22A guides the exhaust gas guided by the horizontal exhaust pipe 21A vertically upward and discharges it from its upper end. The vertical exhaust pipe 22A is provided at the joint between the diesel railcars 10. That is, the vertical exhaust pipe 22A is located outside the car body 14 in the running direction. The vertical exhaust pipe 22A is provided so as to extend upward from the underfloor portion. Specifically, the lower end of the vertical exhaust pipe 22A is connected to the horizontal exhaust pipe 21A extending horizontally from the engine 11A located in the underfloor portion, and extends vertically along the end face 10b. The exhaust port 23A at the upper end of the vertical exhaust pipe 22A is located near the top surface of the car body 14 as shown in FIG. 2. The vertical exhaust pipe 22A is located outside the passage 2 (see FIG. 1) when viewed from the end face 10b side in the sleeper direction, i.e., in the vehicle width direction, and specifically, for example, is located to the right of the passage 2 when viewed from the end face 10b side.

[0030] In the case where engine 11 also includes engine 11B, exhaust pipe 20 also includes an exhaust pipe 20B for engine 11B, as shown in FIG. The exhaust pipe 20B has a horizontal exhaust pipe 21B and a vertical exhaust pipe 22B.

[0031] The horizontal exhaust pipe 21B guides exhaust gas from the engine 11B horizontally toward the cab 10a, and is provided so as to extend horizontally from the engine 11B located under the floor. One end of the horizontal exhaust pipe 21B is connected to the engine 11B, and the other end is connected to the lower end of the vertical exhaust pipe 22B. The other end of the horizontal exhaust pipe 21A is located, for example, on the end face 10b side of the cab 10a in the running direction, i.e., the vehicle longitudinal direction.

[0032] The vertical exhaust pipe 22B guides the exhaust gas guided by the horizontal exhaust pipe 21B vertically upward and discharges it from its upper end. The vertical exhaust pipe 22B is located, for example, on the end face 10b side of the cab 10a in the traveling direction. The vertical exhaust pipe 22B has a lower end connected to the horizontal exhaust pipe 21B and extends in the vertical direction. The exhaust port 23B at the upper end of the vertical exhaust pipe 22B is located near the top surface of the car body 14. The vertical exhaust pipe 22B is located, for example, on the left side when viewed from the end face 10b side in the sleeper direction, i.e., the car body width direction.

[0033] <Findings Obtained by the Inventors> According to the inventors' thorough investigation of the train 1 described above, the end of the end face 10b of the diesel car 10 at the rear in the direction of travel can become contaminated with soot due to the following (A) and the following (B) to (D). (A) Position of the exhaust pipe 20 (specifically, the height position of the exhaust port 23A of the vertical exhaust pipe 22A and the position in the direction of the sleepers) (B) The position of the ceiling unit 15 (specifically, the position in the travel direction), (C) Height of ceiling unit 15 (D) Width (length) of ceiling unit 15 in the sleeper direction

[0034] Therefore, the inventors carried out the following wind tunnel tests and actual vehicle tests. Figures 3 to 5 are diagrams showing the results of the wind tunnel tests. Specifically, each of Figures 3 to 5 shows the configuration of the upper part on the end face 10b side of the diesel railcar 10, and indicates the dimensionless flow velocity (described below) around the configuration by shading and numerical values. Figure 6 is a diagram showing the correspondence between the results of the wind tunnel tests and the results of the actual vehicle tests.

[0035] In the wind tunnel tests, models A and B, which were 1 / 20 scale replicas of train 1, were used. The train 1 modeled on model A had a relatively high ceiling unit 15 and a relatively large width in the sleeper direction (left-right direction in the figure) as shown in Figures 3 and 4. In contrast, the train 1 modeled on model B had a relatively low ceiling unit 15 and a relatively small width in the sleeper direction as shown in Figure 5. In addition, in models A and B, the part equivalent to the exhaust pipe 20 is omitted.

[0036] In addition, in the wind tunnel test, air currents simulating the wind caused by running were applied to models A and B. Specifically, in the wind tunnel test, air currents were irradiated toward models A and B, which were stationary in the wind tunnel, in a predetermined direction corresponding to the running direction.

[0037] In the wind tunnel test, air currents simulating the wind caused by running were applied to models A and B, and the speed of the air currents around models A and B (this air current corresponds to the running wind) was measured in the wind tunnel. A hot wire anemometer was used for this measurement. The target portion of the air current speed measurement using the hot wire anemometer was the portion corresponding to the upper part of the coupling portion of the diesel railcar 10 where the vertical exhaust pipe 22A is disposed. More specifically, the target portion of the speed measurement was the portion corresponding to the upper part of the end face 10b of the diesel railcar 10 at the rear in the running direction. The air current speed measured by the hot wire anemometer is the speed in the above-mentioned specified direction corresponding to the running direction.

[0038] Furthermore, in the wind tunnel test, a non-dimensional flow velocity was calculated. The non-dimensional flow velocity is the ratio (V2 / V1) of the airflow velocity V2 corresponding to the traveling wind around models A and B to the airflow velocity V1 simulating the traveling wind acting on models A and B. The above velocity V1 is specifically the velocity of the airflow flowing in a predetermined direction corresponding to the traveling direction toward models A and B stationary in the wind tunnel. Moreover, the above velocity V2 is specifically the airflow velocity around models A and B measured in the wind tunnel, and more specifically, the airflow velocity around models A and B measured by a hot wire anemometer.

[0039] On the other hand, in the on-board test, the following trains X, Y, and Z were actually run for about 15,000 km.

[0040] Like the train 1 that the model A imitated, the train X had a relatively high ceiling unit 15 and a relatively large width in the sleeper direction of the ceiling unit 15. Furthermore, as shown in Fig. 3, the height position of the exhaust port 23A in the train X was lower than the ceiling unit 15, and the upper end of the vertical exhaust pipe 22A was bent so that the exhaust port 23A discharged exhaust gas toward the center of the car body 14 in the sleeper direction (left-right direction in the figure). Furthermore, in the train X, the vertical exhaust pipe 22A was provided so as to overlap the end of the ceiling unit 15 in the sleeper direction when viewed from the end face 10b side.

[0041] As shown in Fig. 4, train Y, like train 1 and train X that model A imitates, has a relatively high ceiling unit 15 and a relatively large width in the sleeper direction (left-right direction in the figure). Also, like train X, train Y has a vertical exhaust pipe 22A installed so as to overlap with the end of the ceiling unit 15 in the sleeper direction when viewed from the end face 10b side. However, unlike train X, train Y has an exhaust port 23A at approximately the same height as the upper part of the ceiling unit 15.

[0042] Like train 1 which model B imitates, train Z had a relatively low ceiling unit 15 and a relatively small width in the sleeper direction of the ceiling unit 15. Also, as shown in Fig. 5, train Z had an exhaust port 23A at a higher height than the ceiling unit 15 and a vertical exhaust pipe 22A located outside the ceiling unit 15 in the sleeper direction (left-right direction in the figure).

[0043] In the on-board test, before trains X, Y, and Z actually ran, soot was removed from a part of the end face 10b side that had been contaminated with soot, i.e., cleaned. Then, the cleaned part (hereinafter referred to as the "cleaned part"), including its surroundings, was imaged before and after running for about 15,000 km. In the on-board test, the brightness difference between the cleaned part and its surroundings in the image was calculated, and if the rate of change in the brightness difference before and after running exceeded a predetermined threshold (e.g., 0.3), it was determined that "contamination (by soot) exists," and if it did not exceed the threshold, it was determined that "no contamination exists."

[0044] As shown in Fig. 3, in the wind tunnel test, the dimensionless flow velocity of the air flow flowing at the position corresponding to the position of the vertical exhaust pipe 22A of train X (specifically, the position of the exhaust port 23A, more specifically, the center position of the exhaust port 23A) was low at 0.4. In train X, in which the dimensionless flow velocity was low at 0.4 in the wind tunnel test, there was contamination by soot, as shown in Fig. 6.

[0045] As shown in Fig. 4, in the wind tunnel test, the dimensionless flow velocity of the air flow flowing at the position corresponding to the position of the vertical exhaust pipe 22A of train Y was as high as 0.7. In train X, in which the dimensionless flow velocity was as high as 0.7 in the wind tunnel test, there was no soot pollution, as shown in Fig. 6. Furthermore, as shown in Fig. 5, in the wind tunnel test, the dimensionless flow velocity of the airflow flowing at the position corresponding to the position of the vertical exhaust pipe 22A of train Z was as high as 0.85. In train Z having such a high dimensionless flow velocity of 0.85, there was no soot pollution, as shown in Fig. 6.

[0046] In addition, the inventors have confirmed in wind tunnel tests that if the dimensionless flow velocity of the airflow flowing at a position corresponding to the position of the vertical exhaust pipe 22A is 0.6 or more for a train 1, there is no soot contamination in on-board tests.

[0047] These test results show that there is a correlation between the magnitude of the dimensionless flow velocity of the airflow flowing at a position corresponding to the position of the vertical exhaust pipe 22A in the wind tunnel test and whether or not the train 1 is contaminated by soot from the vertical exhaust pipe 22A.

[0048] The method for determining the position of the exhaust pipe according to the present embodiment, which will be described below, is based on the above-mentioned findings.

[0049] <How to determine the position of the exhaust pipe> In the method for determining the position of the exhaust pipe 20 of the train 1 according to the present embodiment, the position of the exhaust pipe 20 is determined based on the determination in a wind tunnel test using a model that imitates the diesel railcar 10. Furthermore, when determining the position of the exhaust pipe 20, the position of the exhaust pipe 20 is determined based on the dimensionless flow velocity. For example, in the method according to the present embodiment, the position of the exhaust pipe 20 is determined to be a position corresponding to a position where the dimensionless flow velocity is equal to or greater than a threshold value in a wind tunnel test.

[0050] The exhaust pipe 20 whose position is to be determined by the method of this embodiment is specifically a vertical exhaust pipe 22A provided at the connecting portion of the diesel railcar 10, and more specifically, a vertical exhaust pipe 22A provided on the diesel railcar 10 at the rear in the direction of travel. When determining the position of the vertical exhaust pipe 22A, the height position and the position in the sleeper direction of the exhaust outlet 23A are determined based on the dimensionless flow velocity obtained from wind tunnel testing in the portion corresponding to above the coupling portion of the diesel railcar 10 (specifically, above the end face 10b of the diesel railcar 10 rearward in the direction of travel).

[0051] The aforementioned threshold value used in determining the position of the exhaust pipe 20 is, for example, 0.6. The threshold value may be determined based on at least one of the exhaust speed of the exhaust from the exhaust pipe 20 (specifically, from the vertical exhaust pipe 22A) and the distance in the running direction from the exhaust pipe 20 (specifically, from the vertical exhaust pipe 22A) to a predetermined part of the diesel railcar 10. The predetermined part is, for example, the end of the ceiling unit 15 closest to the vertical exhaust pipe 22A on the cab 10a side. The predetermined part may also be the rear end of the diesel railcar 10 at the rear in the running direction.

[0052] The position of exhaust outlet 23A is determined within the range of the vehicle clearance. Furthermore, the position of exhaust outlet 23A may be determined so that the entirety of exhaust outlet 23A is located below the upper end of ceiling unit 15.

[0053] <Major Effects> As described above, in this embodiment, the position of the exhaust pipe 20 is determined based on the dimensionless flow velocity in the wind tunnel test. Specifically, a position where the dimensionless flow velocity in the wind tunnel test is relatively high is determined as the position of the vertical exhaust pipe 22A. This makes it possible to prevent the exhaust gas discharged from the exhaust pipe 20 of the traveling diesel railcar 10 from stagnation around the exhaust pipe 20 (specifically, the vertical exhaust pipe 22A). This makes it possible to prevent contamination by soot in the exhaust gas. Specifically, it makes it possible to prevent the outside of the diesel railcar 10 from being contaminated by soot.

[0054] Moreover, what is determined by the method according to the present embodiment is the height position and the position in the sleeper direction of the exhaust port 23A of the vertical exhaust pipe 22A, and the position in the running direction of the vertical exhaust pipe 22A, the position of which is the object of position determination by the method according to the present embodiment, is the connecting portion of the diesel railcar 10. That is, the vertical exhaust pipe 22A, the position of which is the object of position determination by the method according to the present embodiment, is provided at the connecting portion of the diesel railcar. Therefore, by suppressing the exhaust gas from accumulating around the exhaust pipe 20 (specifically, the vertical exhaust pipe 22A) as described above, it is possible to suppress the exhaust gas from accumulating at the connecting portion of the traveling diesel railcar 10. Therefore, it is possible to suppress soot in the exhaust gas from entering the passenger compartment through the passage 2 or the like provided at the connecting portion, thereby preventing the passenger compartment from being polluted.

[0055] Furthermore, the connecting portion of the diesel railcar 10 where the vertical exhaust pipe 22A to be positioned by the method according to this embodiment is provided is a connecting portion between the end faces 10b of the diesel railcars 10, and a ceiling unit 15 is provided on the top surface of the end face 10b side of the diesel railcar 10 so as to protrude upward. In this case, a cavity where airflow is likely to stagnate is formed by the ceiling unit 15 and the top surface on the end face 10b side of each of the connected diesel railcars 10 at the connecting portion where the vertical exhaust pipe 22A to be positioned is provided. Even if a cavity is formed in this way, by determining the position of the vertical exhaust pipe 22A by the method according to this embodiment, it is possible to suppress the exhaust gas discharged from the exhaust pipe 20 (specifically, the vertical exhaust pipe 22A) of the traveling diesel railcar 10 from stagnation around the exhaust pipe 20. Therefore, according to this embodiment, even if a cavity is formed by providing the ceiling unit 15, it is possible to suppress contamination by soot in the exhaust gas. The cavity is not completely hollow, and both end faces of the space within the cavity in the direction of the sleepers are open.

[0056] In this embodiment, the storage space K of the ceiling unit 15 accommodates a storage section 16 that stores compressed air. The compressed air accommodated in the storage section 16 is used to tilt the diesel railcar 10 in a controlled natural pendulum manner. Since a large amount of compressed air is required to tilt the diesel railcar 10, it is necessary to increase the volume of the storage section 16 and the volume of the accommodation space K of the ceiling unit 15. When the volume of the accommodation space K of the ceiling unit 15 increases, the depth (height) and width (length) in the sleeper direction of the above-mentioned cavity also increase, so that the exhaust gas is more likely to remain in the cavity. Even when the air flow is likely to remain in the cavity of the ceiling unit 15 in this way, by determining the position of the exhaust pipe 20 by the method according to this embodiment, it is possible to suppress the exhaust gas discharged from the exhaust pipe 20 from remaining around the exhaust pipe 20 (specifically, the vertical exhaust pipe 22A) of the traveling diesel railcar 10.

[0057] Furthermore, in this embodiment, in the above-mentioned connection portion where the vertical exhaust pipe 22A to be positioned is provided, the distance between the ceiling units 15 on the end faces 10b of the connected diesel railcars 10 is 2m or less. Therefore, the above-mentioned cavities are likely to be formed. Even in such a case where cavities are likely to be formed, by determining the position of the vertical exhaust pipe 22A by the method according to this embodiment, it is possible to suppress the exhaust gas discharged from the exhaust pipe 20 of the traveling diesel railcar 10 from stagnation around the exhaust pipe 20 (specifically, the vertical exhaust pipe 22A).

[0058] <Modification> 1, even when the end faces 10b of the diesel railcars 10 are coupled to each other, or when the driver's cab 10a side of the diesel railcars 10 and the end faces 10b of the diesel railcars 10 are coupled to each other, no cavity as described above is formed around the exhaust port 23B. Therefore, the area around the exhaust port 23B is less susceptible to soot contamination than the area around the exhaust port 23A, but the position of the exhaust port 23B of the vertical exhaust pipe 22B may be determined by the method according to this embodiment instead of or in addition to the position of the exhaust port 23A of the vertical exhaust pipe 22A.

[0059] Although the preferred embodiment of the present invention has been described above, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention.

[0060] In addition, the effects described in this specification are merely explanatory or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to a person skilled in the art from the description of this specification in addition to or in place of the above effects.

[0061] Note that the following configurations also fall within the technical scope of the present disclosure. (1) A method for determining the location of an exhaust pipe for exhausting from an engine of a plurality of coupled diesel railcars, comprising the steps of: determining a position of the exhaust pipe based on the results of a wind tunnel test using a model of the diesel railcar; An exhaust pipe position determination method, in which the determining step determines the position of the exhaust pipe based on a dimensionless flow velocity, which is the ratio of the air flow speed corresponding to the running wind around the model to the running wind speed acting on the model simulated in the wind tunnel test. (2) The exhaust pipe position determination method described in (1), wherein the determining step determines the position of the exhaust pipe's exhaust outlet to a position corresponding to a position where the dimensionless flow velocity is greater than or equal to a threshold value in a wind tunnel test. (3) The exhaust pipe position determination method according to (2) above, wherein the threshold value is 0.6. (4) The exhaust pipe position determination method described in (2) further includes a step of determining the threshold value based on at least one of the exhaust speed of the exhaust from the exhaust pipe and the distance in the traveling direction from the exhaust pipe to a specified part of the diesel railcar. (5) The exhaust pipe to be positioned is provided at a joint between the diesel railcars so as to extend upward from an underfloor portion, The exhaust pipe position determination method according to any one of (1) to (4), wherein the determining step determines the height position and the position in the sleeper direction of the exhaust outlet of the exhaust pipe based on the dimensionless flow velocity above the part corresponding to the connecting part. (6) The exhaust pipe position determination method described in (5) above, wherein the coupling portion of the diesel railcars is the coupling portion between the end faces of the diesel railcars. (7) An exhaust pipe position determination method as described in (6), wherein each of the diesel railcars whose end faces are connected to each other has a ceiling unit that forms an accommodation space and protrudes upwardly from the top surface of the end face side. (8) The exhaust pipe position determination method according to (7), wherein the accommodation space accommodates a storage section that stores compressed air. (9) The trachea position determination method described in (7) or (8), wherein the distance between the ceiling units of the diesel railcars whose end faces are connected to each other is 2 m or less. (10) An exhaust pipe position determination method described in any one of (1) to (9), wherein the dimensionless flow velocity is the ratio of the air flow velocity around the model measured in the wind tunnel to the air flow velocity along a predetermined direction corresponding to the traveling direction of the diesel railcar toward the model stationary in the wind tunnel. [Industrial Applicability]

[0062] The present invention is useful for controlling soot pollution contained in the exhaust gas from diesel railcar engines. [Explanation of symbols]

[0063] 1 Train 2 Passage 10 Diesel railcar 10a Cab 10b Wife face 11 Engine 11A Engine 11B Engine 12 Trolley 13 wheels 14 Body 15 Ceiling unit 16 Storage section 20 Exhaust pipe 20A Exhaust pipe 20B Exhaust pipe 21A Horizontal exhaust pipe 21B Horizontal exhaust pipe 22A Vertical exhaust pipe 22B Vertical exhaust pipe 23A Exhaust port 23B Exhaust port K Containment Space

Claims

1. 1. A method for determining the location of an exhaust pipe for exhausting from an engine of a plurality of coupled diesel railcars, comprising: determining a position of the exhaust pipe based on the results of a wind tunnel test using a model of the diesel railcar; An exhaust pipe position determination method, in which the determining step determines the position of the exhaust pipe based on a dimensionless flow velocity, which is the ratio of the air flow velocity corresponding to the running wind around the model to the running wind velocity acting on the model simulated in the wind tunnel test.

2. 2. The exhaust pipe position determination method according to claim 1, wherein the determining step determines the position of the exhaust outlet of the exhaust pipe to a position corresponding to a position where the dimensionless flow velocity is equal to or greater than a threshold value in a wind tunnel test.

3. The method of claim 2 , wherein the threshold value is 0.

6.

4. 3. The exhaust pipe position determination method of claim 2, further comprising a step of determining the threshold value based on at least one of an exhaust speed of exhaust from the exhaust pipe and a distance in a traveling direction from the exhaust pipe to a predetermined portion of the diesel railcar.

5. The exhaust pipe to be positioned is provided at a joint between the diesel railcars so as to extend upward from an underfloor portion, 5. An exhaust pipe position determination method according to claim 1, wherein the determining step determines a height position and a position in a sleeper direction of an exhaust port of the exhaust pipe based on the dimensionless flow velocity above a portion corresponding to the connecting portion.

6. 6. The exhaust pipe position determining method according to claim 5, wherein the coupling portion of the diesel railcars is a coupling portion between end faces of the diesel railcars.

7. The exhaust pipe position determination method according to claim 6, wherein each of the diesel railcars having their end faces connected to each other has a ceiling unit that forms an accommodation space and protrudes upwardly from the top surface of the end face side of the railcar.

8. The exhaust pipe position determining method according to claim 7 , wherein the accommodation space accommodates a storage portion that stores compressed air.

9. 8. The exhaust pipe position determining method according to claim 7, wherein the distance between the ceiling units of the diesel railcars whose end faces are connected to each other is 2 m or less.

10. The exhaust pipe position determination method according to any one of claims 1 to 4, wherein the dimensionless flow velocity is a ratio of the airflow velocity measured in the wind tunnel around the model to the airflow velocity along a predetermined direction corresponding to the traveling direction toward the model stationary in the wind tunnel.

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