阅读说明：本技术 侧风下列车气动性能与动力学性能协同测试方法及系统 (Method and system for testing aerodynamic performance and dynamic performance of train under crosswind in cooperation mode ) 是由 刘堂红 高鸿瑞 孙博 张洁 熊小慧 刘宏康 于 2021-08-25 设计创作，主要内容包括：本发明公开了侧风下列车气动性能与动力学性能协同测试方法及系统,通过将待测试的列车表面划分为多个矩形单元；获取所述多个矩形单元实际的压力方向以及压差；对于任一个矩形单元A,所述矩阵单元A的压差是指与其在列车的横向或垂向相对的矩形单元B之间的压差；并根据所述多个矩形单元实际的压力方向以及压差计算所述列车的气动荷载,进而修正现有的气动荷载测量方法未考虑矩形单元实际方向带来的误差,提高气动荷载测量的准确性；此外,本发明创新性地提出侧风下列车气动性能与动力学性能协同测试方法及系统,该系统结合气动性能测试结果、车辆横向加速度进行动力学性能测试,无需测力轮对测定轮轨间作用力,从而增大动力学性能测试的适用范围、缩短测试准备周期、降低测试成本。(The invention discloses a method and a system for testing the aerodynamic performance and the dynamic performance of a train under crosswind in a coordinated manner, wherein the surface of the train to be tested is divided into a plurality of rectangular units; acquiring actual pressure directions and pressure differences of the plurality of rectangular units; for any rectangular unit A, the pressure difference of the matrix unit A refers to the pressure difference between the rectangular units B which are transversely or vertically opposite to the matrix unit A in the train; calculating the pneumatic load of the train according to the actual pressure directions and the pressure differences of the plurality of rectangular units, further correcting the error caused by the actual directions of the rectangular units which is not considered in the conventional pneumatic load measuring method, and improving the accuracy of pneumatic load measurement; in addition, the invention innovatively provides a method and a system for testing the aerodynamic performance and the dynamic performance of the train under the crosswind, the system is used for testing the dynamic performance by combining the aerodynamic performance test result and the lateral acceleration of the train, and the force applied between the measuring wheel and the measuring wheel rail by the force measuring wheel is not needed, so that the application range of the dynamic performance test is enlarged, the test preparation period is shortened, and the test cost is reduced.)

1. A method for testing the aerodynamic performance of a train under crosswind is characterized by comprising the following steps:

dividing the surface of a train to be tested into a plurality of rectangular units; acquiring actual pressure directions and pressure differences of the plurality of rectangular units; for any rectangular unit A, the pressure difference of the rectangular unit A refers to the pressure difference between the rectangular units B which are transversely or vertically opposite to the rectangular unit A in the train; and calculating the pneumatic load of the train according to the actual pressure directions and the pressure differences of the plurality of rectangular units.

2. The method for testing the aerodynamic performance of the train under the crosswind according to claim 1, wherein the aerodynamic loading comprises: one or a combination of any one of transverse force, lifting force and side rolling moment applied to the train; the actual pressure direction of the rectangular unit is the normal direction of the rectangular unit;

when the pneumatic load is the transverse force applied to the train, calculating the pneumatic load of the train according to the actual pressure direction and the pressure difference of the plurality of rectangular units, and calculating the pneumatic load according to the following formula:

in the formula, F_yFor transverse forces experienced by the train, Δ p_wliIs the differential pressure S of the centroids of the ith rectangular unit on the windward side and the leeward side of the train_wliIs the orthographic projection area, k, of the ith rectangular unit on the windward side and the leeward side_wliIs a first correction coefficient, k_wliFor decomposing differential pressure from the actual normal direction of the ith rectangular unit on the windward side and the leeward side to F_yThe direction of (2) is calculated by the normal vector of the corresponding rectangular unit; wherein k is_wli＝cosθ_wli，θ_wliThe normal direction and the normal direction F of the ith rectangular unit on the windward side and the leeward side of the train_yThe included angle of the direction;

when the aerodynamic load is the lift force borne by the train, calculating the aerodynamic load of the train according to the actual pressure directions and the pressure differences of the plurality of rectangular units, and calculating the aerodynamic load through the following formula:

in the formula, F_zFor the lift experienced by the train, Δ p_brjIs the differential pressure of the centroid of the jth rectangular unit on the bottom surface and the top surface of the train, S_brjThe orthographic projection surface of the jth rectangular unit on the bottom surface and the top surfaceProduct, k_brjIs the second correction coefficient, k_brjFor resolving differential pressure from the actual normal direction of the jth rectangular cell on the bottom and top surfaces to F_zThe direction of the streamline part is not directly obtained by decomposition due to the inconsistent directions of the upper surface and the lower surface of the streamline part during testing, and is obtained by interpolation of a numerical database;

when the pneumatic load is the side rolling moment applied to the train, calculating the pneumatic load of the train according to the actual pressure direction and the pressure difference of the plurality of rectangular units, and calculating the pneumatic load according to the following formula:

in the formula, M_xIs the side rolling moment, L, experienced by the train_wliIs the force arm corresponding to the centroid of the ith rectangular unit on the windward side and the leeward side, L_brjThe moment arm corresponding to the centroid of the jth rectangular unit on the bottom surface and the top surface is provided.

3. The method for testing the aerodynamic performance of the train under the crosswind according to claim 1, wherein the pressure difference between each rectangular unit A on the surface of the train and the rectangular unit B which is opposite to the rectangular unit A in the transverse direction or the vertical direction of the train is acquired by an aerodynamic load testing module, and the aerodynamic load testing module consists of a first beat type pressure sensing sheet, a second beat type pressure sensing sheet, a first sampling pipe, a second sampling pipe and a differential pressure sensor; the differential pressure sensor is arranged at the bottom of the train, a first beat type pressure sensing piece is arranged at the centroid of the rectangular unit A and is connected with a first interface of the differential pressure sensor through a first sampling pipe, a second beat type pressure sensing piece is arranged at the centroid of the rectangular unit B and is connected with a second interface of the differential pressure sensor through a second sampling pipe;

when the rectangular unit A is positioned on the windward side of the train and the rectangular unit B is positioned on the leeward side of the train, the first interface is a positive pressure interface of the differential pressure sensor, and the second interface is a negative pressure interface of the differential pressure sensor;

when the rectangular unit A is positioned on the bottom surface of the train, the rectangular unit B is positioned on the top surface of the train, the first interface is a positive pressure interface of the differential pressure sensor, and the second interface is a negative pressure interface of the differential pressure sensor.

4. The method for testing the aerodynamic performance of the train under the crosswind according to claim 3, wherein the first flap type pressure sensing piece arranged on the windward side or the leeward side of the train and the second flap type pressure sensing piece arranged on the windward side or the leeward side of the train are installed in a mode that copper pipes face upwards, all the first sampling pipes and all the second sampling pipes are the same in length, and the lengths of the first sampling pipes and the second sampling pipes are larger than the half perimeter of the cross section of the equal straight section of the train.

5. The method for testing the aerodynamic performance of the train under the crosswind according to claim 4, wherein the length of the first sampling pipe and the length of the second sampling pipe are both less than or equal to 8 meters.

6. A method for testing the aerodynamic performance and the dynamic performance of a train under crosswind in a collaborative mode is characterized by comprising the following steps:

acquiring the pneumatic load of the train by adopting the method for testing the pneumatic performance of the train under the crosswind as claimed in claims 1-5, and acquiring the transverse acceleration of the train;

and calculating the dynamic index of the train according to the pneumatic load and the transverse acceleration of the train.

7. The method for testing the aerodynamic performance and the dynamic performance of the train under the crosswind according to claim 6, wherein the dynamic indexes of the train comprise an overturning coefficient and a derailment coefficient of the train, and the overturning coefficient is calculated by the following formula:

M_la＝m₀a_qz_CoG0+m₁a_qz_CoG1+m₂a_qz_CoG2

M_CoG＝m₁gy₁+m₂gy₂

M_x,lee＝M_x+F_z(b_A-y₂)

M_m＝(m₀+m₁+m₂)gb_A

in the formula, M_laFor moments caused by unbalanced lateral acceleration, m₀Is an unsprung mass formed by wheel pairs, m₁The mass between a first train and a second train of the train consisting of bogie frames; m is₂The mass of the train is more than two series of the train consisting of the train body; z is a radical of_CoG0Is unsprung mass m₀Height of center of mass from rail surface, z_CoG1Is the mass m between the first and second series₁Height of center of mass from rail surface, z_CoG2Has a mass m of two or more series₂The height of the center of mass from the rail surface; a is_qIs an unbalanced lateral acceleration; m_CoGIs the mass m between the first train and the second train₁And a mass m of more than two₂Respectively undergo transverse displacement y₁And y₂The induced moment g is the acceleration of gravity; y is₁Is the mass m between the first and second series₁Transverse displacement of (y)₂Has a mass m of two or more series₂The lateral displacement of (a); m_x,leeThe side rolling moment of the contact point of the leeward side wheel rail is influenced by the side wind of the train; m_xMoment of side rolling experienced by the train, F_zFor the lift experienced by the train, b_AThe distance between the windward side wheel rail contact point and the corresponding leeward side wheel rail contact point is half long; m_mFor the restoring moment caused by the train mass, D is the overturning coefficient of the train, f_mIs a process factor;

the derailment coefficient is calculated by the following formula:

in the formula, F_yIs the lateral force experienced by the train.

8. The method for testing the aerodynamic performance and the dynamic performance of a crosswind train in cooperation as claimed in claim 6, wherein the mass m between the first system and the second system₁Transverse displacement y of₁The obtaining is realized by the following formula:

in the formula: a is_qFor unbalanced lateral acceleration, i.e. results of a test of the lateral acceleration of the vehicle body, K_y1A lateral stiffness for each series of springs;

mass m of more than two series₂Transverse displacement y of₂The obtaining is realized by the following formula:

in the formula: k_y2For transverse stiffness per secondary spring, K_z2Vertical stiffness per secondary spring, K_arbStiffness of the anti-roll torsion bar per bogie, h₂Height of secondary spring from rail surface, b₂Is the transverse span of the secondary spring.

9. The method for testing the aerodynamic performance and the dynamic performance of the train under the crosswind according to claim 6, wherein the lateral acceleration of the train is measured by an acceleration sensor installed under the train; after the overturning coefficient and the derailing coefficient of the train are obtained, the method further comprises the following steps:

and evaluating the train operation safety according to the overturning coefficient and the derailing coefficient of the train, and outputting an alarm signal when the potential safety hazard of the train is evaluated.

10. A computer system comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the steps of the method of any one of claims 1 to 9 are performed when the computer program is executed by the processor.

Technical Field

The invention relates to the field of train pneumatic performance and dynamic index testing, in particular to a method and a system for testing the pneumatic performance and the dynamic performance of a train under crosswind in a coordinated mode.

Background

Under the action of crosswind, the aerodynamic performance of the train is deteriorated, the aerodynamic load is obviously increased, the running safety of the train is influenced, and the train is derailed or overturned in severe cases. In order to improve the train operation safety under the action of crosswind, scholars at home and abroad carry out a great deal of research on the pneumatic performance of the train under the action of crosswind through numerical simulation, model tests and real vehicle tests. Due to the pulsating wind characteristics of an actual wind field, numerical simulation and model test are difficult to completely simulate the unsteady aerodynamic performance of a train in the wind field, and unsteady aerodynamic loads are considered to be an important reason for causing the train to overturn. The real vehicle test can directly obtain the train pneumatic performance in the actual wind field, evaluate the train operation safety, further help numerical simulation and model test better simulate the problems, and provide a basis for further researching the train operation safety under the action of crosswind.

Unlike the model test, the real vehicle test cannot measure the pneumatic load using a force balance. In the prior art, a real vehicle test is carried out, and the pneumatic load on a stationary vehicle under the action of crosswind is measured through a force sensor. And the pneumatic load of the static vehicle model under the action of crosswind is measured by a force sensor through carrying out a full-size model test. This method can only be used for stationary trains and cannot measure the aerodynamic loads experienced during train operation. For a moving train, a real train test is also carried out, a test vehicle is a 25K type passenger train, and the pneumatic load is obtained through the block integration of the surface pressure of the vehicle.

The pressure integration method can be well adapted to pneumatic load testing in real vehicle tests, but the actual direction of each rectangular unit is not considered, so that the tested pneumatic load has large measurement error.

Therefore, how to solve the technical problem that the accuracy of the existing pneumatic load measurement method is not high has become an urgent need to be solved by the technical personnel in the field.

In addition, the dynamic response test of the train under the action of crosswind at present mainly adopts a force measuring wheel pair to measure the acting force between wheel rails, and then stability indexes such as derailment coefficients, wheel weight load shedding rate, transverse force of wheel shafts and the like are calculated. The force measuring wheel pair can obtain accurate results, but the cost is high, the installation is complex, and the installation period is long. And the real vehicle test under the action of crosswind requires that a tester quickly finishes the installation and debugging of test equipment after receiving a strong wind forecast, and requires that the installation period of the test equipment is short. In addition, real vehicle tests under the action of crosswind are often carried out on operating vehicles, but the vehicles provided with the force measuring wheel sets cannot operate normally, and the force measuring wheel sets need to be repeatedly assembled and disassembled before and after the tests, so that the operating requirements cannot be met.

Therefore, it is an urgent technical problem to be solved to research a dynamic rapid testing method and a dynamic rapid testing system applicable to a moving train.

Disclosure of Invention

The invention provides a method and a system for cooperatively testing the pneumatic performance and the dynamic performance of a train under the action of crosswind, which are used for solving the technical problems of low accuracy of the conventional pneumatic load measuring method, small application range, long preparation period and high cost of the conventional dynamic performance testing method.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

a method for testing the aerodynamic performance of a train under crosswind comprises the following steps:

dividing the surface of a train to be tested into a plurality of rectangular units; acquiring actual pressure directions and pressure differences of the plurality of rectangular units; for any rectangular unit A, the pressure difference of the rectangular unit A refers to the pressure difference between the rectangular units B which are transversely or vertically opposite to the rectangular unit A in the train; and calculating the pneumatic load of the train according to the actual pressure directions and the pressure differences of the plurality of rectangular units.

Preferably, the pneumatic loading comprises: one or a combination of any one of transverse force, lifting force and side rolling moment applied to the train; the actual pressure direction of the rectangular unit is the normal direction of the rectangular unit;

when the pneumatic load is the transverse force applied to the train, calculating the pneumatic load of the train according to the actual pressure direction and the pressure difference of the plurality of rectangular units, and calculating the pneumatic load according to the following formula:

in the formula, F_yFor transverse forces experienced by the train, Δ p_wliIs the differential pressure S of the centroids of the ith rectangular unit on the windward side and the leeward side of the train_wliIs the orthographic projection area, k, of the ith rectangular unit on the windward side and the leeward side_wliIs a first correction coefficient, k_wliFor decomposing differential pressure from the actual normal direction of the ith rectangular unit on the windward side and the leeward side to F_yThe direction of (2) is calculated by the normal vector of the corresponding rectangular unit; wherein k is_wli＝cosθ_wli，θ_wliThe normal direction and the normal direction F of the ith rectangular unit on the windward side and the leeward side of the train_yThe included angle of the direction;

when the aerodynamic load is the lift force borne by the train, calculating the aerodynamic load of the train according to the actual pressure directions and the pressure differences of the plurality of rectangular units, and calculating the aerodynamic load through the following formula:

in the formula, F_zFor the lift experienced by the train, Δ p_brjIs the differential pressure of the centroid of the jth rectangular unit on the bottom surface and the top surface of the train, S_brjIs the orthographic projection area, k, of the jth rectangular cell on the bottom and top surfaces_brjIs the second correction coefficient, k_brjFor resolving differential pressure from the actual normal direction of the jth rectangular cell on the bottom and top surfaces to F_zDirection of (2) due to streamlines during testingThe directions of the upper surface and the lower surface of the model part are inconsistent and cannot be obtained by direct decomposition, and the model part is obtained by interpolation of a numerical database;

when the pneumatic load is the side rolling moment applied to the train, calculating the pneumatic load of the train according to the actual pressure direction and the pressure difference of the plurality of rectangular units, and calculating the pneumatic load according to the following formula:

in the formula, M_xIs the side rolling moment, L, experienced by the train_wliIs the force arm corresponding to the centroid of the ith rectangular unit on the windward side and the leeward side, L_brjThe moment arm corresponding to the centroid of the jth rectangular unit on the bottom surface and the top surface is provided.

Preferably, the pressure difference between each rectangular unit A on the surface of the train and the rectangular unit B which is transversely or vertically opposite to the rectangular unit A on the surface of the train is acquired by a pneumatic load testing module, and the pneumatic load testing module consists of a first beat type pressure sensing sheet, a second beat type pressure sensing sheet, a first sampling pipe, a second sampling pipe and a differential pressure sensor; the differential pressure sensor is arranged at the bottom of the train, a first beat type pressure sensing piece is arranged at the centroid of the rectangular unit A and is connected with a first interface of the differential pressure sensor through a first sampling pipe, a second beat type pressure sensing piece is arranged at the centroid of the rectangular unit B and is connected with a second interface of the differential pressure sensor through a second sampling pipe;

when the rectangular unit A is positioned on the windward side of the train and the rectangular unit B is positioned on the leeward side of the train, the first interface is a positive pressure interface of the differential pressure sensor, and the second interface is a negative pressure interface of the differential pressure sensor;

when the rectangular unit A is positioned on the bottom surface of the train, the rectangular unit B is positioned on the top surface of the train, the first interface is a positive pressure interface of the differential pressure sensor, and the second interface is a negative pressure interface of the differential pressure sensor.

Preferably, the first clapping type pressure sensing piece arranged on the windward side or the leeward side of the train and the second clapping type pressure sensing piece arranged on the windward side or the leeward side of the train both adopt an installation mode that a copper pipe faces upwards, all the first sampling pipes and all the second sampling pipes are the same in length, and the lengths of the first sampling pipes and the second sampling pipes are larger than the half perimeter of the cross section of the equal straight section of the train.

Preferably, the length of the first sampling tube and the length of the second sampling tube are both less than or equal to 8 meters.

A method for testing the aerodynamic performance and the dynamic performance of a train under crosswind in a collaborative mode comprises the following steps:

acquiring the pneumatic load of the train by adopting the method for testing the pneumatic performance of the train under the crosswind, and acquiring the transverse acceleration of the train;

and calculating the dynamic index of the train according to the pneumatic load and the transverse acceleration of the train.

The method for testing the aerodynamic performance and the dynamic performance of the train under the crosswind in a collaborative manner is characterized in that the dynamic indexes of the train comprise an overturning coefficient and a derailing coefficient of the train, and the overturning coefficient is calculated through the following formula:

M_la＝m₀a_qz_CoG0+m₁a_qz_CoG1+m₂a_qz_CoG2

M_CoG＝m₁gy₁+m₂gy₂

M_x,lee＝M_x+F_z(b_A-y₂)

M_m＝(m₀+m₁+m₂)gb_A

in the formula, M_laFor moments caused by unbalanced lateral acceleration, m₀Is an unsprung mass formed by wheel pairs, m₁For the first and second trains of a train consisting of bogie frames(ii) a mass of; m is₂The mass of the train is more than two series of the train consisting of the train body; z is a radical of_CoG0Is unsprung mass m₀Height of center of mass from rail surface, z_CoG1Is the mass m between the first and second series₁Height of center of mass from rail surface, z_CoG2Has a mass m of two or more series₂The height of the center of mass from the rail surface; a is_qIs an unbalanced lateral acceleration; m_CoGIs the mass m between the first train and the second train₁And a mass m of more than two₂Respectively undergo transverse displacement y₁And y₂The induced moment g is the acceleration of gravity; y is₁Is the mass m between the first and second series₁Transverse displacement of (y)₂Has a mass m of two or more series₂The lateral displacement of (a); m_x,leeThe side rolling moment of the contact point of the leeward side wheel rail is influenced by the side wind of the train; m_xMoment of side rolling experienced by the train, F_zFor the lift experienced by the train, b_AThe distance between the windward side wheel rail contact point and the corresponding leeward side wheel rail contact point is half long; m_mFor the restoring moment caused by the train mass, D is the overturning coefficient of the train, f_mIs a process factor;

the derailment coefficient is calculated by the following formula:

in the formula, F_yIs the lateral force experienced by the train.

Preferably, the mass m between the first and second series₁Transverse displacement y of₁The obtaining is realized by the following formula:

in the formula: a is_qFor unbalanced lateral acceleration, i.e. results of a test of the lateral acceleration of the vehicle body, K_y1A lateral stiffness for each series of springs;

mass m of more than two series₂Transverse displacement ofy₂The obtaining is realized by the following formula:

in the formula: k_y2For transverse stiffness per secondary spring, K_z2Vertical stiffness per secondary spring, K_arbStiffness of the anti-roll torsion bar per bogie, h₂Height of secondary spring from rail surface, b₂Is the transverse span of the secondary spring.

Preferably, the lateral acceleration of the train is measured by an acceleration sensor installed under the train; after the overturning coefficient and the derailing coefficient of the train are obtained, the method further comprises the following steps:

and evaluating the train operation safety according to the overturning coefficient and the derailing coefficient of the train, and outputting an alarm signal when the potential safety hazard of the train is evaluated.

A computer system comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the method when executing the computer program.

The invention has the following beneficial effects:

1. the method and the system for testing the aerodynamic performance and the dynamic performance of the train in a coordinated manner under the action of crosswind divide the surface of the train to be tested into a plurality of rectangular units; acquiring actual pressure directions and pressure differences of the plurality of rectangular units; for any one rectangular unit A, the pressure difference of the matrix unit A refers to the pressure difference between the rectangular units B which are transversely or vertically opposite to the rectangular units A in the train; calculating the pneumatic load of the train according to the actual pressure directions and the pressure differences of the plurality of rectangular units, further correcting the error caused by the actual directions of the rectangular units which is not considered in the conventional pneumatic load measuring method, and improving the accuracy of pneumatic load measurement; in addition, the invention innovatively provides a method and a system for testing the aerodynamic performance and the dynamic performance of the train under the crosswind, the system is used for testing the dynamic performance by combining the aerodynamic performance test result and the lateral acceleration of the train, the force applied between the measuring wheel and the measuring wheel rail by the force measuring wheel is not needed, the application range of the dynamic performance test is greatly enlarged, the preparation period of the dynamic performance test is shortened, and the cost of the dynamic performance test is reduced.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of a three-mass model in a preferred embodiment of the invention;

FIG. 2 is a schematic structural diagram of a system for testing the aerodynamic performance and the dynamic performance of a crosswind train in cooperation in the preferred embodiment of the invention;

FIG. 3 is a schematic installation diagram of a system for testing the aerodynamic performance and dynamic performance of a crosswind train in cooperation in a preferred embodiment of the invention;

FIG. 4 is a schematic view of the fixed orientation of the flapper pressure sensing tab in a preferred embodiment of the invention;

FIG. 5 is a graph comparing measurement errors for different lengths of sample tubes in a preferred embodiment of the invention;

FIG. 6 is a pneumatic load test result in a preferred embodiment of the present invention;

FIG. 7 is the results of a kinetic index test in a preferred embodiment of the present invention;

FIG. 8 is a data processing flow of the system for testing the aerodynamic performance and the dynamic performance of the crosswind train in cooperation in the preferred embodiment of the present invention;

FIG. 9 is a flow chart of a method for testing the aerodynamic performance and the dynamic performance of a crosswind train in cooperation in a preferred embodiment of the present invention;

the figure is marked with:

1. the device comprises a train, 2 parts of a beat type pressure sensing sheet, 3 parts of a sampling pipe, 4 parts of a differential pressure sensor, 5 parts of an acceleration sensor, 6 parts of a data acquisition device, 7 parts of an upper computer, 8 parts of a trigger.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

The first embodiment is as follows:

the implementation discloses a method for testing the aerodynamic performance of a train under crosswind, which comprises the following steps:

dividing the surface of a train to be tested into a plurality of rectangular units; acquiring actual pressure directions and pressure differences of the plurality of rectangular units; for any rectangular unit A, the pressure difference of the matrix unit A refers to the pressure difference between the rectangular units B which are transversely or vertically opposite to the matrix unit A in the train; and calculating the pneumatic load of the train according to the actual pressure directions and the pressure differences of the plurality of rectangular units.

In addition, in this embodiment, a method for testing the aerodynamic performance and the dynamic performance of a train in crosswind in a collaborative manner is also disclosed, which includes the following steps:

acquiring the pneumatic load of the train by adopting the method for testing the pneumatic performance of the train under the crosswind, and acquiring the transverse acceleration of the train;

and calculating the dynamic index of the train according to the pneumatic load and the transverse acceleration of the train.

In addition, in the embodiment, a computer system is also disclosed, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, the steps of the method are implemented.

The method and the system for testing the aerodynamic performance and the dynamic performance of the train in a coordinated manner under the action of crosswind divide the surface of the train to be tested into a plurality of rectangular units; acquiring actual pressure directions and pressure differences of the plurality of rectangular units; for any rectangular unit A, the pressure difference of the matrix unit A refers to the pressure difference between the rectangular units B which are transversely or vertically opposite to the matrix unit A in the train; calculating the pneumatic load of the train according to the actual pressure directions and the pressure differences of the plurality of rectangular units, further correcting the error caused by the actual directions of the rectangular units which is not considered in the conventional pneumatic load measuring method, and improving the accuracy of pneumatic load measurement; in addition, the invention innovatively provides a method and a system for testing the aerodynamic performance and the dynamic performance of the train under the crosswind, the system is used for testing the dynamic performance by combining the aerodynamic performance test result and the lateral acceleration of the train, the force applied between the measuring wheel and the measuring wheel rail by the force measuring wheel is not needed, the application range of the dynamic performance test is greatly enlarged, the preparation period of the dynamic performance test is shortened, and the cost of the dynamic performance test is reduced.

Example two:

the second embodiment is the preferred embodiment of the first embodiment, and is different from the first embodiment in that specific steps of the cooperative test method for the aerodynamic performance and the dynamic performance of the train under the action of the crosswind are optimized, and a specific structure of the cooperative test system for the aerodynamic performance and the dynamic performance of the train is introduced, and the cooperative test method comprises the following steps:

in the embodiment, the method for testing the aerodynamic performance of the train under crosswind comprises the following steps:

dividing the surface of a train to be tested into a plurality of rectangular units; namely, dividing a projection plane of the side face/top face of the train body of the running train to obtain a row A in the length direction of the train body and a row B in the height/width direction of the train body, wherein the row A is A multiplied by B rectangular units;

acquiring actual pressure directions and pressure differences of the plurality of rectangular units; the differential pressure of the centroid of each rectangular unit is directly measured by adopting a small-range and high-precision differential pressure sensor, the differential pressure is decomposed from the actual normal direction of the rectangular unit to the direction of the corresponding pneumatic force, and then the transverse force, the lifting force and the side rolling moment of the vehicle are obtained by adopting an integral method. For each rectangular cell, the centroid differential pressure is measured, the pneumatic load on the entire cell is calculated, and the sum is summed to obtain the pneumatic load of the vehicle, i.e., the

In the formula: f_yAnd F_zRespectively transverse and lifting forces, M, to which the vehicle is subjected_xIs the roll moment, Δ p, experienced by the vehicle_wliIs the differential pressure, delta p, of the centroid of the ith rectangular unit on the windward side and the leeward side of the train_brjIs the differential pressure of the centroid of the jth rectangular unit on the bottom surface and the top surface of the train, S_wliIs the orthographic projection area of the ith rectangular unit on the windward side and the leeward side, S_brjIs the orthographic projection area of the jth rectangular unit on the bottom surface and the top surface, L_wliIs the force arm corresponding to the centroid of the ith rectangular unit on the windward side and the leeward side, L_brjThe moment arm corresponding to the centroid of the jth rectangular unit on the bottom surface and the top surface is provided. k is a radical of_wliAnd k is_brjAre all correction coefficients. k is a radical of_wliFor decomposing differential pressure from the actual normal direction of the ith rectangular unit on the windward side and the leeward side to F_yThe direction of (2) is calculated by the normal vector of the corresponding rectangular unit; k is a radical of_brjFor resolving differential pressure from the actual normal direction of the jth rectangular cell on the bottom and top surfaces to F_zThe direction of the streamline part is not directly obtained by decomposition due to the inconsistent directions of the upper surface and the lower surface of the streamline part during testing, and is obtained by interpolation of a numerical database.

In addition, the embodiment also discloses a method for testing the aerodynamic performance and the dynamic performance of the train under crosswind in a coordinated manner, and the method uses a three-mass model to calculate and obtain an overturning coefficient and a derailment coefficient according to the test results of the transverse force, the lifting force and the rolling moment obtained by the train aerodynamic performance test and the transverse acceleration of the train body.

Wherein the three-mass model of the train reduces the vehicle to a three-part mass, i.e., unsprung mass m, as shown in FIG. 1₀(mainly wheel set), mass m between primary and secondary₁(mainly bogie frame)And a mass m of more than two₂(mainly vehicle body). Under the action of side wind, the masses of all parts shift transversely, and the unsprung mass m₀Is y₀Mass m between primary and secondary systems₁Is y₁Mass m of more than two series₂Is y₂。z_CoG0Is unsprung mass m₀Height of center of mass from rail surface, z_CoG1Is the mass m between the first and second series₁Height of center of mass from rail surface, z_CoG2Has a mass m of two or more series₂The height of the mass center from the rail surface. The distance between the windward side wheel rail contact point b and the leeward side wheel rail contact point a is 2b_A＝1.5m。

Wherein the mass m between the first and second series₁Transverse displacement of

In the formula: a is_qFor unbalanced lateral acceleration, i.e. results of a test of the lateral acceleration of the vehicle body, K_y1For each series spring lateral stiffness.

Mass m of more than two series₂The lateral displacement of (a) is:

in the formula: k_y2For transverse stiffness per secondary spring, K_z2Vertical stiffness per secondary spring, K_arbStiffness of the anti-roll torsion bar per bogie, h₂Height of secondary spring from rail surface, b₂Is the transverse span of the secondary spring.

The vehicle is influenced by the side wind and has side rolling moment on the contact point a of the leeward side wheel rail

M_x,lee＝M_x+F_z(b_A-y₂)， (8)

The restoring torque caused by the vehicle mass is:

M_m＝(m₀+m₁+m₂)gb_A， (9)

(m₀+m₁+m₂)g＝8P， (10)

in the formula: g is the gravitational acceleration and P is the average wheel weight of the left and right wheels.

From a mass m between one series and two series₁And a mass m of more than two₂Respectively undergo transverse displacement y₁And y₂Induced moment

M_CoG＝m₁gy₁+m₂gy₂， (11)

The moment caused by the unbalanced lateral acceleration is:

M_la＝m₀a_qz_CoG0+m₁a_qz_CoG1+m₂a_qz_CoG2， (12)

according to the overturning coefficient definition, there are

In the formula: p₂For wheel-rail pressure, P, on the wheel-weight-loading side of the vehicle wheel₁The wheel rail pressure on the wheel load relief side is determined.

In FIG. 1, the left side of the wheel set is the wheel load increasing side, the right side is the wheel load decreasing side, and a torque balance equation is obtained for a wheel-rail contact point a on the leeward side, including

-m₀gb_A-m₁g(b_A-y₁)-m₂g(b_A-y₂)+4P₁·2b_A+M_la+M_x,lee＝0， (14)

The overturning coefficient can be obtained through the joint type (9) - (14). In order to ensure that the train operation safety is conservative, a method factor f is introduced_mThe process factors for different vehicles are listed in table 1. The overturning coefficient is:

the derailment coefficient is:

TABLE 1 method factors for different vehicles

	Passenger car	Truck	Locomotive
				Method factor fm	1.20	1.15	1.20

In addition, in this embodiment, a system for testing the train aerodynamic performance and the dynamic performance in cooperation under crosswind is also disclosed, and the system for testing the train aerodynamic performance and the dynamic performance is used for completing the test of the train aerodynamic performance and the dynamic performance, and is composed of modules such as an aerodynamic load test module, an acceleration test module, a speed test module, a mileage test module, a data acquisition device 6, an upper computer 7, a trigger 8 and the like, and can realize the functions of a/D conversion of a tested analog signal, real-time processing, storage, display, analysis and the like of data, as shown in fig. 2.

The data acquisition equipment 6 is internally provided with a NET2801 Ethernet bus data acquisition card, and the sampling frequency is set to be 256 Hz. A6-order II-type Chebyshev filter is adopted, the attenuation of a stop band is 60dB, and the cut-off frequency is 43 Hz.

The data acquisition card can automatically acquire the analog signal to be detected and send the analog signal to the upper computer 7. According to the sampling theorem, the sampling frequency of the data acquisition card is reasonably set, so that the original analog signal has no aliasing distortion on the frequency spectrum.

The pneumatic load testing module consists of a beat type pressure sensing sheet 2, a sampling pipe 3 and a differential pressure sensor 4. As shown in fig. 3, a flap sensor chip 2 is fixed at a vehicle surface measurement point (centroid of the rectangular unit described above), and the flap sensor chip 2 is connected to a differential pressure sensor 4 fixed under the vehicle via a sampling pipe 3. The windward side and the leeward side (bottom surface and top surface) are correspondingly connected with the same differential pressure sensor 4, the windward side (bottom surface) is connected with a positive pressure interface, and the leeward side (top surface) is connected with a negative pressure interface, so that the positive directions of the transverse force and the lifting force are ensured. In order to prevent rainwater from entering the sampling pipe 3 and affecting the accuracy of the test result, the copper pipe is kept upward when the clap-type pressure sensing piece 2 is fixed, as shown in fig. 4. To keep the test signals synchronized, the length of the sampling tube 3 should be kept consistent.

For pulsating pressure signals with different frequencies, the length of the sampling tube influences the amplitude of the pulsating pressure signals, and the overlong sampling tube can greatly attenuate the pressure amplitude. The pulsating pressure signals around the train under the action of crosswind are usually low-frequency signals, so the influence of the length of the sampling tube on the pressure amplitude during low frequency needs to be studied in depth to ensure the accuracy of the test result of the invention. As shown in FIG. 5, the pressure amplitude error of different pressure pulsation frequencies corresponds to different lengths of sampling pipes, the length of the sampling pipe is increased from 1m to 10m, and the pressure pulsation frequency is increased from 0.2Hz to 1.0 Hz. When the length of the sampling tube is not more than 3m, the pressure amplitude obtained by the sampling tube is larger than the original pressure amplitude. Subsequently, the pressure amplitude obtained by the sampling tube begins to decay, the greater the pressure pulsation frequency, the more significant the amplitude decay. For the low-frequency pulsating pressure signal, when the length of the sampling tube does not exceed 8m, the pressure amplitude error is less than 5 percent, and the test result is acceptable. Due to the fact that the frequency of unsteady aerodynamic loads on the train 1 under the action of crosswind is low, when the length of the sampling pipe 3 does not exceed 8m, the measurement error is less than 5%, as shown in fig. 5.

The differential pressure signal measured by the differential pressure sensor 4 is automatically collected by a data acquisition card and sent to an upper computer 7(PC) in the vehicle. After filtering and data cleaning are carried out by the upper computer 7, the transverse force, the lifting force and the rolling moment of the vehicle are obtained through formulas (3) - (5). The results of the lateral force, lift force and roll moment tests are shown in fig. 6.

The acceleration test is implemented by the acceleration sensor 5. The acceleration sensor 5 is fixed under the vehicle and used for testing the transverse acceleration of the vehicle body, and is also automatically collected by the data acquisition card and sent to the upper computer 7. After filtering and data cleaning are carried out by the upper computer 7, the overturning coefficient and the derailment coefficient of the train are obtained through formulas (15) and (16) respectively by combining vehicle dynamic parameters input into a test system in advance, and therefore the running safety of the train 1 under the action of crosswind is evaluated. The lateral acceleration, the overturning coefficient and the derailment coefficient of the vehicle are collected as shown in fig. 7.

The speed test and the mileage test are both realized by a GPS positioner. The GPS positioner can measure the speed of the train 1 in real time, and the mileage can be obtained by calculating the integral of the speed in time.

The trigger 8 is connected to the data acquisition card to realize the synchronous action of the pneumatic load test and the acceleration test.

In the test, the upper computer 7 processes and stores the test data in real time, and can realize the functions of filtering, data cleaning, data visualization, data integration and the like, as shown in fig. 8. The test data is first low pass filtered to prevent signal interference. And secondly, cleaning the test data, and further filtering the data, wherein the steps comprise cleaning repeated data, cleaning abnormal data, filling missing data, binning and the like. And then calculating and visualizing the data of the transverse force, the lifting force, the roll moment, the transverse acceleration, the overturning coefficient, the derailing coefficient, the speed, the mileage and the like of the vehicle. And finally, centralizing the test data to provide a data basis for further analyzing the running safety of the train 1 under the action of crosswind. Meanwhile, before the test, the line condition and the actual line condition (including information such as curve radius, superelevation, windproof facility types, mileage, long and short chains and the like) are input into the test system in advance, and during the test, the line condition and the actual line condition can be obtained in real time according to the mileage, so that the test data is analyzed, and the influence factors of the train pneumatic performance and the dynamic performance are obtained.

In addition, the test system has strong expandability. Instruments such as a vehicle-mounted anemometer, an inclination angle sensor and a displacement sensor can be connected to the data acquisition card, so that the instruments are integrated into the test system. The camera equipment can also be arranged under the vehicle and connected with the upper computer 7 to observe the relationship between the wheel and the rail in real time.

In summary, the actual orientation of the rectangular cells is not considered compared to the existing methods of measuring the pneumatic load of a train by pressure integration. The invention introduces a correction coefficient k_wliAnd k is_brjThe differential pressure is decomposed from the actual direction of the rectangular unit to the direction of the transverse force and the lifting force, and the error caused by the fact that the actual direction of the rectangular unit is not considered is corrected. In addition, the invention innovatively provides a method and a system for cooperatively testing the aerodynamic performance and the dynamic performance of the train under crosswind on the basis of improving the aerodynamic performance test of the train, calculates the dynamic indexes such as the overturning coefficient, the derailment coefficient and the like by combining the aerodynamic performance test result, the transverse acceleration of the train and the dynamic parameters, and provides a basis for analyzing the detailed rule of the aerodynamic load of the train and the related parameters of the dynamic indexes, which are the most main factors of the running safety under the action of crosswind.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.