CN102673426B - Method for determining fluctuation velocity and tension of contact line for high-speed rail in consideration of air damping - Google Patents

Abstract

The invention discloses a method for determining fluctuation velocity and tension of a contact line for a high-speed rail in consideration of air damping. The tension is designed under the condition of considering the air damping and knowing the fluctuation speed of the contact line, so that the situation that the tension of the contact line is sufficient is guaranteed, and the traveling security is enhanced; and meanwhile, the fluctuation speed of the contact line is designed under the condition of considering the air damping and knowing the tension of the contact line, so that the highest operation speed of a train is limited, and resonance of the contact line is avoided to result in damage of the train, thereby the traveling security is increased. With the adoption of the method, the defect of the traditional designing method is made up, and the method has the advantages of comprehensive consideration factors and more security.

Description

Consider that air-damped high ferro contact wire velocity of wave motion and tension force determines method

Technical field

The present invention considers air-damped high ferro contact wire velocity of wave motion and Tension design method, divides and belongs to operation, department of Transport according to International Patent Classification (IPC) (IPC); General vehicle class; The power circuit of elec. vehicle or along the device group of rail; The technical field of air wire and annex used thereof.

Background technology

Applied to high-speed railway touching net design is complicated, and wherein important one comprises contact wire Tension design.The interim 860-869 page Woonkyung of the 17th volume the 6th M.Kim of periodical " Journal of Mechanical Science and Technology ", Jeung Tae Kim, the relation of tension force and wave propagation in the multiple chain type hanging system in the Shinkansen studied in the article " A numerical study on dynamic characteristics of a catenary " of Jung Soo Kim and Jae Won Lee, think that tension force often reduces 1.46kN, wave propagation reduces 18km/h, the impact of visible tension force on velocity of wave motion, and velocity of wave motion is the key factor that affects highest running speed of train, if train running speed is the same with contact wire velocity of wave motion, must cause contact wire resonance, its amplitude is infinitely great, to cause contact system to damage, when the at present domestic velocity of wave motion at design high ferro contact system and tension force, do not consider air-damped impact, for high speed railway, safe operation has impact for this.The object of the invention is to consider air-damped impact, improve safety.

Summary of the invention

The object of the invention is to consider air damping impact, proposed the new mode of high ferro contact wire velocity of wave motion and Tension design, improve high ferro safety.

Consider that air-damped high ferro contact wire velocity of wave motion and tension force determines method, it is characterized in that: in the time of the velocity of wave motion of design high ferro contact system and contact wire tension force, by considering that air damping can design and calculate corresponding contact wire tension force and velocity of wave motion, particular content and method of designing are:

A, carry out wind tunnel test, measure the lift coefficient C under the different angle of attack of contact wire _lwith drag coefficient C _d, obtain

The damping coefficient C after air damping impact is considered in B, calculating _air:

$C_{\mathrm{air}}=C-\frac{1}{2}{\mathrm{\ρ}}_{\mathrm{air}}\·U\·B(\frac{{\mathrm{dC}}_L}{\mathrm{d\α}}+C_D){|}_{\mathrm{\α}=0},$

C is contact wire damping coefficient, ρ _airfor current density, U is contact wire air-flow velocity when motionless, and B is contact wire width;

C, calculating ${\mathrm{\&xi;}}_{\mathrm{air}}=\frac{{\mathrm{<figure-callout\; id="2"\; label="C\; air"\; filenames="HDA00001707835300022.png"\; state="\{\{state\}\}">C</figure-callout>}}_{\mathrm{air}}}{2\mathrm{\&rho;w}}=\frac{C-\frac{1}{2}{\mathrm{\&rho;}}_{\mathrm{air}}\&CenterDot;U\&CenterDot;B(\frac{{\mathrm{dC}}_L}{\mathrm{d\&alpha;}}+C_D){|}_{\mathrm{\&alpha;}=0}}{2\mathrm{\&rho;w}},$ W is the circular frequency that hangs contact system vibration undamped oscillations;

E, according to contact wire tension force, calculate contact wire velocity of wave motion:

$v=\frac{2\mathrm{\&pi;f}\sqrt{1-{\mathrm{\&xi;}}_{\mathrm{air}}^2}}{\sqrt{\sqrt{{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HDA00001707835300022.png"\; state="\{\{state\}\}">T</figure-callout>}}{2\mathrm{EI}}\right)}^2+\frac{\mathrm{\&rho;}{\left(2\mathrm{\&pi;f}\right)}^2}{\mathrm{EI}}}-\frac{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HDA00001707835300022.png"\; state="\{\{state\}\}">T</figure-callout>}}{2\mathrm{EI}}}}---\left(1\right)$

V is contact wire velocity of wave motion (m/s), and π is circular constant, and f is frequency (Hz), and T is contact wire tension force (N), and EI is bending strength (Nm ²), ρ is contact wire density (kg/m);

E, calculating contact wire tension force:

$T=\frac{{\mathrm{<figure-callout\; id="2"\; label="v"\; filenames="HDA00001707835300022.png"\; state="\{\{state\}\}">v</figure-callout>}}^2\mathrm{\&rho;}{\left(2\mathrm{\&pi;f}\right)}^2-\frac{{\left(2\mathrm{\&pi;f}\right)}^4{(1-{\mathrm{\&xi;}}_{\mathrm{air}}^2)}^2\&CenterDot;\mathrm{EI}}{v^2}}{{\left(2\mathrm{\&pi;f}\right)}^2(1-{\mathrm{\&xi;}}_{\mathrm{air}}^2)}---\left(2\right);$

F, according to set up railway power traction power supply design regulation data bank, calculate β value (the highest train speed/velocity of wave motion) and safety factor, check whether design contact wire tension force and velocity of wave motion meet design manual requirement, reach requirement and finish this part design; Do not reach requirement, according to operating mode, adjust contact wire Tensity size, resize ratio is 10%, gets back in step D and calculates, and gets back to afterwards step e and recalculates, and so repeats, until meet the requirements, output gained T and data are to subsequent processing device.

According to formula (1), the velocity of wave motion that it is characterized in that contact wire except with tension force, bending strength, linear density and frequency dependence, and the damping coefficient of air also has much relations; And the damping coefficient of air is directly related with galloping force coefficient, with current density ρ _air, air-flow velocity horizontal component, galloping force coefficient

width B, linear density and the frequency of contact wire are relevant, and galloping force coefficient and body surface form are closely related.

According to formula (2), it is characterized in that finding out under given high speed railway contact wire velocity of wave motion Tensity size requirement and the requirement to air damping coefficient of contact wire; Also can find out under given tension force and air damping coefficient, the variation range of contact wire velocity of wave motion, for design and the construction of high speed railway contact wire provide design and basis.

Accompanying drawing explanation

The maximum working tension of Fig. 1 copper alloy contact wire, transmitting speed, β value

Fig. 2 is contact system velocity of wave under given tension force and bending strength and the relation curve of frequency-linear density

Fig. 3 is the relation curve of contact wire velocity of wave motion and air damping coefficient

Fig. 4 is the relation curve that contact wire velocity of wave motion is combined with tension force-air damping coefficient.

The specific embodiment

Below in conjunction with accompanying drawing, embodiments of the invention are elaborated: the present embodiment is implemented under take technical solution of the present invention as prerequisite, provided detailed implementation process, but protection scope of the present invention is not limited to following embodiment.

This example is take design train running speed as the contact wire of 350Km/h is as example, and A, B, C step data need to draw by test, and this example directly enters step D, designs.

D, get ξ _air=0.1, according in People's Republic of China's industry standard " TB 1009-2005J452-2005 railway power traction power supply design regulation " 5.1.2, " tension force of main track contact wire should not be less than: 10kN (v≤120km/h); 13kN (120km/h < v≤160km/h)." train running speed is 350Km/h in this example, velocity of wave motion must be greater than 160km/h, shows according to external a large amount of operations practices and test, and running velocity is velocity of wave motion 65% ~ 72% time, has best operational effect.Figure classification number U238 in this example reference, article numbering 1007-936X(2005) in z-0074-04 " high speed railway contact wire tension force scheme " table 3(be accompanying drawing 1) verify.Can suppose that for the first time contact tension force is 15kN, frequency f is 1Hz, and EI is 130Nm ², density p is 1.35kg/m, calculates velocity of wave motion:

$v=\frac{2\mathrm{\&pi;f}\sqrt{1-{\mathrm{\&xi;}}_{\mathrm{air}}^2}}{\sqrt{\sqrt{{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HDA00001707835300022.png"\; state="\{\{state\}\}">T</figure-callout>}}{2\mathrm{EI}}\right)}^2+\frac{\mathrm{\&rho;}{\left(2\mathrm{\&pi;f}\right)}^2}{\mathrm{EI}}}-\frac{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HDA00001707835300022.png"\; state="\{\{state\}\}">T</figure-callout>}}{2\mathrm{EI}}}}$

$=\frac{2\mathrm{\&pi;}\&times;1\sqrt{1-{0.1}^2}}{\sqrt{\sqrt{{\left(\frac{20000}{2\&times;130}\right)}^2+{\frac{1.35\&times;(2\mathrm{\&pi;}\&times;1)}{130}}^2}-\frac{20000}{130}}}$

$=377.577\mathrm{Km}/h$

Obviously undesirable;

E, show according to external a large amount of operations practices and test, running velocity is velocity of wave motion 65% ~ 72% time, has best operational effect, the circuit that is 350Km/h for road speed, and adjustment velocity of wave motion is 500Km/h:

$T=\frac{{\mathrm{<figure-callout\; id="2"\; label="v"\; filenames="HDA00001707835300022.png"\; state="\{\{state\}\}">v</figure-callout>}}^2\mathrm{\&rho;}{\left(2\mathrm{\&pi;f}\right)}^2-\frac{{\left(2\mathrm{\&pi;f}\right)}^4{(1-{\mathrm{\&xi;}}_{\mathrm{air}}^2)}^2\&CenterDot;\mathrm{EI}}{v^2}}{{\left(2\mathrm{\&pi;f}\right)}^2(1-{\mathrm{\&xi;}}_{\mathrm{air}}^2)}$

$=\frac{{(500/3.6)}^2\&times;1.35\&times;{(2\mathrm{\&pi;}\&times;1)}^2-\frac{{\left(2\mathrm{\&pi;f}\right)}^4{(1-{0.1}^2)}^2\&times;130}{{(500/3.6)}^2}}{{(2\mathrm{\&pi;}\&times;1)}^2(1-{0.1}^2)}$

$=26.304\mathrm{kN}$

Now, need in contact wire material depot, carry out type selecting, if there is no corresponding material, require further improvement calculating, until there is qualified material, finish this part design.

Conventionally, contact wire velocity of wave propagation computing formula is

if adopt in this example, can calculate v=502.5121Km/h, in engineering design, the least bit of difference, a thousand li of mistake, by the method for designing in more known this patent more accurately, reliably, has practical significance for safe train operation.

By counting statistics, can obtain contact system velocity of wave under given tension force shown in accompanying drawing 2 and bending strength and the relation curve of frequency-linear density.

Calculate according to formula 1, can consider the contact wire velocity of wave motion in air damping situation, curve as shown in Figure 3.The concrete Data Comparison of part is as shown in the table, and wherein air damping is 0 to be the data of not considering under air damping impact:

The speed unit that fluctuates in upper table is Km/h, and cps is Hz, and air damping is dimensionaless coefficient.

Calculate according to formula 2, obtain the relation curve that contact wire velocity of wave motion is combined with tension force-air damping coefficient, as shown in Figure 4, the concrete Data Comparison of part is as shown in the table:

Shang Biaozhong tension force unit is N, and velocity of wave motion unit is Km/h.

By above example, method of designing of the present invention has been described, the method for designing before perfect, the safety that has improved design parameters, has practical significance for safe train operation.

Claims (1)

1. consider that air-damped high ferro contact wire velocity of wave motion and tension force determines method for one kind, it is characterized in that: in the time of the velocity of wave motion of high ferro contact system and contact wire tension force, by considering that air damping can calculate corresponding contact wire tension force and velocity of wave motion, particular content and method of designing are:

A, carry out wind tunnel test, measure the lift coefficient C under the different angle of attack of contact wire _lwith drag coefficient C _d, obtain;

The damping coefficient C after air damping impact is considered in B, calculating _air:

$C_{\mathrm{air}}=C-\frac{1}{2}{\mathrm{\&rho;}}_{\mathrm{air}}\&CenterDot;U\&CenterDot;B(\frac{d{C}_L}{\mathrm{d\&alpha;}}+C_D){|}_{\mathrm{\&alpha;}=0},$

C is contact wire damping coefficient, ρ _airfor current density, U is contact wire air-flow velocity when motionless, and B is contact wire width;

C, calculating ${\mathrm{\&xi;}}_{\mathrm{air}}=\frac{C_{\mathrm{air}}}{2\mathrm{\&rho;w}}=\frac{C-\frac{1}{2}{\mathrm{\&rho;}}_{\mathrm{air}}\&CenterDot;U\&CenterDot;B(\frac{d{C}_L}{\mathrm{d\&alpha;}}+C_D){|}_{\mathrm{\&alpha;}=0}}{2\mathrm{\&rho;w}},$ W is the circular frequency that hangs contact system vibration undamped oscillations;

D, calculating contact wire tension force:

$T=\frac{v^2\mathrm{\&rho;}{\left(2\mathrm{\&pi;f}\right)}^2-\frac{{\left(2\mathrm{\&pi;f}\right)}^4{(1-{\mathrm{\&xi;}}_{\mathrm{air}}^2)}^2\&CenterDot;\mathrm{EI}}{v^2}}{{\left(2\mathrm{\&pi;f}\right)}^2(1-{\mathrm{\&xi;}}_{\mathrm{air}}^2)};$

E, according to known contact wire tension force, design calculation contact wire velocity of wave motion:

$v=\frac{2\mathrm{\&pi;f}\sqrt{1-{\mathrm{\&xi;}}_{\mathrm{air}}^2}}{\sqrt{\sqrt{{\left(\frac{T}{2\mathrm{EI}}\right)}^2+\frac{\mathrm{\&rho;}{\left(2\mathrm{\&pi;f}\right)}^2}{\mathrm{EI}}}-\frac{T}{2\mathrm{EI}}}},$

V is contact wire velocity of wave motion, and π is circular constant, and f is frequency, and T is contact wire tension force, and EI is bending strength, and ρ is contact wire density;

F, according to set up railway power traction power supply design regulation data bank, calculate β value and safety factor, β=the highest train speed/velocity of wave motion, checks whether design contact wire tension force and velocity of wave motion meet design manual requirement, reaches requirement and finishes this part design; Do not reach requirement, according to operating mode, adjust contact wire Tensity size, resize ratio is 10%, gets back in step D and calculates, and gets back to afterwards step e and recalculates, and so repeats, until meet the requirements, output gained T and data are to subsequent processing device.

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