High-speed train lift wing and wing-train cooperative aerodynamic characteristic engineering estimation method

Abstract

The invention relates to the field of high-speed train aerodynamics and motor train unit equipment, in particular to a high-speed train lift wing and wing-train cooperative aerodynamic characteristic engineering estimation method. A high-speed train assembled with a plurality of unit groups of lift wings is taken as an object, and key technical parameters are optimized aiming at aerodynamic design and model selection of the lift wings of the high-speed train and collaborative layout on the high-speed train on the basis of referring to finite basic theories, numerical simulation and experimental tests; the aerodynamic characteristics such as the wing profile lift coefficient and distribution characteristic, the lift line characteristic and the resistance characteristic of the lift wing and wing train system work, and the wing train cooperative operation gas work interference effect are rapidly determined through engineering experience and a theoretical method, and universality evaluation and general engineering calculation of the aerodynamic characteristics of the high-speed train are achieved. Powerful reference and technical support can be provided for development and application of lifting wing systems of wheel-rail trains with the speed of 400 + km / h and high-speed maglev trains.

Description

Technical Field

[0001] The present invention relates to the fields of high-speed train aerodynamics and multiple unit train equipment, and particularly relates to an engineering estimation method for the lift wing of a high-speed train and the collaborative aerodynamic characteristics of a winged train. Background Art

[0002] With the increase in the operating speed, the wheel wear of wheel-rail trains will be further aggravated, and the wheel turning cycle and service life will inevitably be shortened during this process. In order to reduce the life cycle cost of trains at higher speeds, the concept of a high-speed train with a lift wing has been proposed in research, breaking through the traditional aerodynamic shape design concept of high-speed trains, combining the respective advantages of high-speed trains and aircraft, and hoping to achieve overall energy conservation and consumption reduction of high-speed trains by increasing the aerodynamic lift of the trains.

[0003] At the end of the 20th century, Tohoku University in Japan first proposed the design concept of an "aerodynamic suspension train", which provides lift for the train by arranging ground effect wings near the ground and utilizing the ground effect to increase lift. At the same time, preliminary design research was carried out on the airfoils used in the aerodynamic suspension train, and it was considered that its transport economic efficiency is higher than that of maglev trains and high-speed civil airliners. An experimental model of the aerodynamic suspension train was made, and a conceptual design scheme with a lift wing added was proposed. "Wing-like structures" were arranged on the roof and the side of the car body, and some selectable airfoils were pointed out. The above research shows that designing a lift wing with good aerodynamic characteristics is the key to the lift wing train technology. So far, various design schemes have been proposed around this goal. For example, the Chinese utility model patent with the authorization announcement number CN113602299B, the invention name of which is a telescopic wing device for aerodynamic force regulation of a high-speed train, a high-speed train and a control method, the authorization announcement number CN210133111U, the invention name of which is a side wing lift control mechanism for a high-speed rail transit train, and a high-speed train wing device disclosed in CN202175052U and CN202175053U. However, generally speaking, they have not been fully combined with the actual development of high-speed trains, especially in aspects such as the lift wing structure design scheme, installation and layout form, control method and in-vehicle application, which are basically in a blank state. Based on this, under the background of the great development of high-speed intelligent and green railway equipment in China at the present stage, researching and developing a high-speed train lift wing device with obvious lift increase effect, small drag coefficient, low aerodynamic noise, small installation space, high applicability to existing high-speed trains, intelligent regulation and effective response to complex wind environments is one of the urgent problems to be solved for the speed increase operation of high-speed trains and the implementation of energy conservation and consumption reduction and the development of green railway equipment.

[0004] The lift wing uses the air during the high-speed operation stage of the high-speed train as the main braking power source to regulate the lift during the high-speed operation of the high-speed train. Its braking smoothness and safety are directly affected by the external wind environment. When a high-speed train equipped with a lift wing device is running, as the running speed and the side wind intensity of the external environment increase, the aerodynamic effect becomes more prominent, the aerodynamic performance of the high-speed train deteriorates rapidly, the aerodynamic lateral force and lift both increase non-linearly, and the aerodynamic load it receives seriously affects the dynamic performance of the train vehicle track, which may lead to train derailment, overturning and casualties. As an auxiliary lift increase during the high-speed stage of the train, the best applicable speed range of the lift wing device is 400 km / h and above. The higher the running speed, the greater the effective aerodynamic lift, and the more prominent the subsequent aerodynamic effect. The evaluation and calculation of aerodynamic characteristics are usually obtained through wind tunnel tests or on-line tests, but the test cost and test difficulty are relatively large, and it is generally difficult to carry out the adaptability application research of the lift wing under multiple working conditions. Therefore, based on the reference of limited basic theories, numerical simulations and test tests, this invention conducts a universal evaluation and general calculation of aerodynamic characteristics for the aerodynamic design selection of the high-speed train lift wing and the key technical parameters of the collaborative layout optimization on the high-speed train, and proposes an engineering estimation method for the collaborative aerodynamic characteristics of the high-speed train lift wing and the wing-train, which is a necessary condition for the development and application of the lift wing device. Summary of the Invention

[0005] In order to adapt the aerodynamic characteristics of the multi-unit lift wing of the high-speed train and the collaborative aerodynamic control with the external environment, and quickly clarify the lift coefficient and distribution characteristics of the wing profile, the lift line characteristics, the drag characteristics, the aerodynamic interference effect and other aerodynamic characteristics of the lift wing and the wing-train system through general experience and theoretical methods, this invention proposes an engineering estimation method for the collaborative aerodynamic characteristics of the high-speed train lift wing and the wing-train.

[0006] To achieve the above technical objectives, this invention is implemented by adopting the following technical solutions:

[0007] An engineering estimation method for the collaborative aerodynamic characteristics of a high-speed train lift wing and a wing-train. The method takes a high-speed train equipped with a multi-unit lift wing as the research object. Based on basic theories, numerical simulations and test tests, for the aerodynamic design selection of the high-speed train lift wing and the key technical parameters of the collaborative layout optimization on the high-speed train, a universal evaluation and general calculation of aerodynamic characteristics are carried out. The estimated content of the aerodynamic characteristics of the high-speed train lift wing mainly includes the lift coefficient of the wing profile and its distribution characteristics along the train's transverse direction, the lift line characteristics and the drag characteristics; the estimated content of the aerodynamic characteristics of the wing-body combination mainly includes the aerodynamic interference effect of the high-speed train body on the lift wing and the aerodynamic interference effect of the lift wing on the inherent flow field of the high-speed train and the layout of the roof equipment and facilities;

[0008] The multi-unit lift wing is a lift control body adapted for aerodynamic collaborative utilization of high-speed trains with a speed of 400 km / h or above. The overall structure of the lift wing smoothly transitions symmetrically from the center wing section to the left and right sides horizontally. It is movably connected to the lift wing control mechanism part on the roof of the high-speed train through a lifting frame, and can adapt to and meet the selection of multiple angles of attack of the lift wing.

[0009] The specific engineering estimation method for the lift wing and wing-car collaborative aerodynamic characteristics of high-speed trains includes the following steps:

[0010] 1) Engineering estimation of the lift coefficient of the wing section of the high-speed train lift wing and its distribution characteristics along the train's transverse direction:

[0011] When the high-speed train lift wing is a straight wing with a large aspect ratio, the lift coefficient of the wing section is calculated using the lifting line theory; when the high-speed train lift wing is a lift control wing with a small aspect ratio or a lift control wing with a swept angle, the lift coefficient of the wing section is calculated using the lifting surface theory.

[0012] The lift coefficient of the high-speed train lift wing in engineering estimation is equal to the sum of the basic lift coefficient and the additional lift coefficient. The general calculation formula is:

[0013] C L ′(z) = C L ′ b (z) + C L ′ a (z), where: C L ′(z) is the lift coefficient of the high-speed train lift wing; C L ′ b (z) is the basic lift coefficient of the high-speed train lift wing; C L ′ a (z) is the additional lift coefficient of the high-speed train lift wing;

[0014] 11) Determination of the basic lift coefficient of the lift wing: When the high-speed train lift wing is in an environment without crosswind or the aerodynamic torsion of the lift wing caused by the line environment, the basic lift coefficient of the high-speed train is calculated according to the following formula:

[0015]

[0016] where: C L ′ b (z) is the basic lift coefficient of the high-speed train; is the lift line slope corresponding to the infinitely long wing of the lift wing; is the vertical velocity potential function; α 0a is the absolute zero-lift angle of attack due to the geometric torsion caused by the operating line conditions and the body motion state changes of the high-speed train;

[0017] 12) Determination of additional lift coefficient of lift wing: The additional lift coefficient of the lift wing of the high-speed train is estimated by engineering experience by referring to the parameter characteristics of the elliptical lift wing under the same conditions. The calculation formula is as follows:

[0018]

[0019] In the formula: b0 is the chord length at the root of the reference elliptical lift wing; z is the vertical vector value; k is the total transverse length of the lift wing;

[0020] 2) Determination of lift line characteristics of lift wing of high-speed train: The lift line of the lift wing of the high-speed train is characterized by zero-lift angle of attack, lift line slope and maximum lift coefficient. The calculation formula is:

[0021]

[0022] In the formula: α is the angle of attack; α0 is the zero-lift angle of attack, and the calculated value is where α 0∞ is the angle of attack corresponding to an infinitely long lift wing, and η is the root-tip ratio of the lift wing; is the reference velocity potential function; is the lift line slope of the lift wing, and the calculation formula is as follows:

[0023]

[0024] In the formula: λ is the aspect ratio; χ 1 / 2 is the sweep angle at 0.5 chord length;

[0025] The maximum lift coefficient of the lift wing of the high-speed train is estimated through the maximum lift coefficient C Lmax0 of the middle wing section of the lift wing where the longitudinal center plane of the train is located and the maximum lift coefficient C Lmax1 of the wing sections at both ends of the lift wing of the high-speed train. The calculation formula is: C Lmax = k s (C Lmax0 + C Lmax1 ) / 2; where for the straight lift wings symmetrically arranged transversely on the roof of the high-speed train, the estimated coefficient k s ranges from 0.75 to 0.85; for the lift wings with sweep angles symmetrically arranged transversely on the roof of the high-speed train, the estimated coefficient k s ranges from 0.86 to 0.95;

[0026] 3) Determination of aerodynamic drag characteristics of lift wing of high-speed train:

[0027] The aerodynamic drag coefficient C D of the lift wing of the high-speed train is estimated to be equal to the zero-lift aerodynamic drag coefficient C D0The sum of the zero-lift aerodynamic drag coefficient C DL is expressed as: C D = C D0 + C DL ; where the zero-lift aerodynamic drag coefficient C D0 is calculated using the parameters at the mean chord of the high-speed train's lift wing during engineering estimation. The calculation formula is:

[0028] C D0 = (2C F ) bav (1 + 0.1t + 0.4t 2 ),

[0029] In the formula, C F is the friction drag coefficient for the same lift wing chord length; t is the relative thickness of the lift wing, representing the maximum dimensionless height between the upper arc and the lower chord of the lift wing, i.e., t = max[y u (x) - y d (x)], where y u (x) is the relative coordinate of the upper arc of the lift wing, and y d (x) is the relative coordinate of the lower chord; k a is an empirical constant, and the estimated value range is 0.15 - 0.2, k b is an empirical constant, and the estimated value range is 0.41 - 0.5;

[0030] Among them, the lift-induced drag coefficient C DL is equal to the sum of the induced aerodynamic drag coefficient and the viscous pressure difference drag coefficient C Dn during engineering estimation. The calculation formula for C Di is: C DL = C Di + C Dn ;

[0031] Among them, in the formula, (0.05λ - δ) / πλ is a correction term, which is usually determined by wind tunnel test data of a high-speed train with a lift wing assembly not less than 1:8 model or in-service vehicle line test data. δ is the correction coefficient of the high-speed train's lift wing, and the estimated value range is 0.05 - 0.15 according to the degree of deviation of the lift wing from the optimal planar shape;

[0032] 4) Quantitative evaluation of the interference effect of the high-speed train's lift wing:

[0033] 41) Calculation of the aerodynamic interference coefficient of the series-connected lift wings on the high-speed train roof: The aerodynamic interference coefficient of the series-connected lift wings on the high-speed train roof is characterized by the longitudinal aerodynamic drag F D of the series-connected wings. The calculation formula is as follows:

[0034]

[0035] Wherein, C d0 is the aerodynamic drag coefficient of a single set of lift wings on the roof of the vehicle, and 1 set of layout conditions is taken during engineering estimation; C d1 (i) is the direct interference coefficient of the i-th set of lift wings from the front to the back in the windward direction; A d is the longitudinal projected area of the lift wing device; n is the number of sets of series-connected lift wings installed; ρ is the air density of the operating environment; v is the operating speed of the high-speed train equipped with lift wings;

[0036] 42) Calculation of the interference effect between the lift wings of the high-speed train equipped with lift wings and the train:

[0037] The interference effect between the lift wings of the high-speed train equipped with lift wings and the train is estimated by the overall aerodynamic co-lift coefficient of the two, and the calculation formula is as follows:

[0038] C Lt =(L ws +L sw ) / (0.5ρv 2 S0), where: L ws is the lift generated by the lift wings considering the adaptation to the high-speed train; L sw is the lift generated by the high-speed train considering the lift wings; S0 is the projected area of the lift wings in the vertical direction of the high-speed train;

[0039] Preferably, for the flat direct lift wings adapted to the high-speed train in step 11), the corresponding absolute zero-lift angle of attack α 0a due to the geometric twist of the high-speed train caused by the change of the running line conditions and the body motion state exists, and the value is equal to the angle between the zero-lift line and the zero-lift line of the middle wing section, and is calculated by the following formula:

[0040]

[0041] Wherein: F L is the lift of the lift wings; b(z) is the vertical chord length function of the lift wings; S is the wing section area of the longitudinal center plane of the train where the lift wings are located.

[0042] Preferably, the effective installation space of the multi-unit lift wing in the transverse section is the area above the roof between the railway building clearance and the vehicle clearance. The width (K) of the area is less than or equal to the transverse outer dimension of the train, and the height (H) of the area is less than the lifting height of the pantograph of the high-speed train minus the safety height margin of 400 mm. The geometric design dimensions of the lift wing meet the space scale requirements of the railway construction clearance and the vehicle clearance in the transverse section. The transverse width (k) of the lift wing is less than or equal to the transverse outer dimension of the train and is 1600 - 2000 mm. The chord length (c) of the lift wing is equal to 0.5 - 1 times the transverse width (k) and is 800 - 2000 mm. The maximum thickness (tmax) of the center wing section of the lift wing is 250 - 400 mm, and the vertical distance (cx) from the position of the maximum thickness (tmax) to the leading edge end is 200 - 400 mm. The leading edge radius (r) of the lift wing is equal to 20 - 50 mm. The trailing edge angle (R2) of the lift wing is equal to 5 - 15 degrees.

[0043] Preferably, the installation lifting frame is connected to the center position of the longitudinal chord line on the lower chord surface of the lift wing. When the lift wing is working, under the support and lifting control of the installation lifting frame, the normal working height (h) is 300 - 800 mm, and the normal working angle of attack (R) is 0 - 30 degrees.

[0044] The beneficial effects of the present invention are as follows: Based on the reference of limited basic theories, numerical simulations and experimental tests, for the key technical parameters of the aerodynamic design selection of the high-speed train lift wing and the collaborative layout optimization on the high-speed train, through general experience and theoretical methods, the lift coefficient and distribution characteristics of the wing section where the lift wing and the wing-car system work, the lift line characteristics, the drag characteristics, the aerodynamic interference effects and other aerodynamic characteristics can be quickly and clearly obtained, realizing the universal evaluation of the aerodynamic characteristics of high-speed trains and general engineering calculations, and providing strong reference and technical support for the development and application of the lift wing systems of wheel-rail trains and high-speed maglev trains with a speed of 400+ km / h. Description of the Drawings

[0045] Figure 1 It is a flowchart of the engineering estimation method for the aerodynamic characteristics of the high-speed train lift wing and the wing-car collaboration of the present invention;

[0046] Figure 2 It is the installation layout space dimension requirements of the high-speed train adapted to the present invention under the constraint conditions of the railway clearance;

[0047] Figure 3 It is three typical lift wing structures and key technical parameters adapted to the present invention;

[0048] Figure 4 It is a three-dimensional structure diagram of a high-speed train lift wing device adapted to the present invention (adapted to multiple angles of attack, multiple angles of rotation and multiple heights);

[0049] Figure 5 This is a three-dimensional structure diagram of another lift wing device (wing and adjustment device) adapted for the present invention for high-speed trains. Specific embodiments

[0050] The present invention will be further described below in conjunction with the accompanying drawings:

[0051] An engineering estimation method for the collaborative aerodynamic characteristics of a high-speed train lift wing and wing-car. The method takes a high-speed train equipped with a multi-unit lift wing as the research object. Based on basic theory, numerical simulation and experimental testing, for the key technical parameters of the aerodynamic design selection of the high-speed train lift wing and the collaborative layout optimization on the high-speed train, a universal evaluation and general calculation of the aerodynamic characteristics are carried out. The estimation content of the aerodynamic characteristics of the high-speed train lift wing mainly includes the lift coefficient of the wing section and its transverse distribution characteristics along the train, the lift line characteristics, and the drag characteristics; the estimation content of the aerodynamic characteristics of the wing-body combination mainly includes the aerodynamic interference effect of the high-speed train body on the lift wing and the aerodynamic interference effect of the lift wing on the inherent flow field of the high-speed train and the layout of the roof equipment and facilities.

[0052] The multi-unit lift wing is a lift control body for aerodynamic collaborative utilization adapted for high-speed trains with a speed of 400 km / h or more. The overall structure of the lift wing smoothly transitions symmetrically from the central wing section to the left and right sides transversely; it is movably connected to the lift wing control mechanism part on the roof of the high-speed train through a lifting frame, and can adapt to the selection work of multiple angles of attack of the lift wing; the lifting frame is connected to the central position of the longitudinal chord line on the lower chord surface of the lift wing. When the lift wing is working, under the support and lifting control of the lifting frame, the normal working height (h) is 300 - 800 mm, and the normal angle of attack (R) is 0 - 30 degrees.

[0053] As Figure 1 shown, the engineering estimation method for the collaborative aerodynamic characteristics of a high-speed train lift wing and wing-car specifically includes the following steps:

[0054] 1) Engineering estimation of the lift coefficient of the wing section of the high-speed train lift wing and its transverse distribution characteristics along the train:

[0055] When the high-speed train lift wing is a straight wing with a large aspect ratio, the lift coefficient of the wing section is calculated using the lift line theory; when the high-speed train lift wing is a lift control wing with a small aspect ratio or a lift control wing with a sweep angle, the lift coefficient of the wing section is calculated using the lift surface theory.

[0056] The lift coefficient of the high-speed train lift wing in engineering estimation is equal to the sum of the basic lift coefficient and the additional lift coefficient. The general calculation formula is:

[0057] C L′(z) = C L ′ b (z) + C L ′ a (z), where: C L ′(z) is the lift coefficient of the lift wing of the high-speed train; C L ′ b (z) is the basic lift coefficient of the lift wing of the high-speed train; C L ′ a (z) is the additional lift coefficient of the lift wing of the high-speed train;

[0058] 11) Determination of the basic lift coefficient of the lift wing: When the lift wing of the high-speed train is in an environment without crosswind or the aerodynamic torsion of the lift wing caused by the line environment, the basic lift coefficient of the high-speed train is calculated according to the following formula:

[0059]

[0060] where: C L ′ b (z) is the basic lift coefficient of the high-speed train; is the lift line slope corresponding to the infinitely long wing of the lift wing; is the vertical velocity potential function; α 0a is the absolute zero-lift angle of attack existing due to the geometric torsion caused by the operating line conditions and the body motion state changes of the high-speed train;

[0061] 12) Determination of the additional lift coefficient of the lift wing: The additional lift coefficient of the lift wing of the high-speed train is estimated by engineering experience by referring to the parameter characteristics of the elliptical lift wing under the same conditions. The calculation formula is as follows:

[0062]

[0063] where: b0 is the root chord length of the reference elliptical lift wing; z is the vertical vector value; k is the total lateral length of the lift wing;

[0064] 2) Determination of the lift line characteristics of the lift wing of the high-speed train: The lift line of the lift wing of the high-speed train is characterized by the zero-lift angle of attack, the lift line slope, and the maximum lift coefficient. The calculation formula is:

[0065]

[0066] where: α is the angle of attack; α0 is the zero-lift angle of attack, and the calculated value is where α 0∞ is the angle of attack corresponding to the infinitely long lift wing, and η is the root-to-tip ratio of the lift wing; is the reference velocity potential function; is the lift line slope of the lift wing, and the calculation formula is as follows:

[0067]

[0068] In the formula: λ is the aspect ratio; χ 1 / 2 is the sweep angle at 0.5 chord length;

[0069] The maximum lift coefficient of the high-speed train lift wing is estimated through the maximum lift coefficient C of the middle wing section of the lift wing located on the longitudinal center plane of the train Lmax0 and the maximum lift coefficients C of the wing sections at both ends of the high-speed train lift wing Lmax1 for engineering estimation. The calculation formula is: C Lmax = k s (C Lmax0 + C Lmax1 ) / 2; where for the lift wings symmetrically arranged transversely on the roof of the high-speed train, the estimated coefficient k s ranges from 0.75 to 0.85; for the lift wings with sweep angles symmetrically arranged transversely on the roof of the high-speed train, the estimated coefficient k s ranges from 0.86 to 0.95;

[0070] 3) Determination of the aerodynamic drag characteristics of the high-speed train lift wing:

[0071] The aerodynamic drag coefficient C of the high-speed train lift wing D is estimated to be equal to the sum of the zero-lift aerodynamic drag coefficient C D0 and the induced drag coefficient C DL , expressed as: C D = C D0 + C DL ; where the zero-lift aerodynamic drag coefficient C D0 is calculated using the parameters at the mean chord of the high-speed train lift wing during engineering estimation. The calculation formula is:

[0072] C D0 = (2C F ) bav (1 + 0.1t + 0.4t 2 ),

[0073] In the formula, C F is the friction drag coefficient of the lift wing with the same chord length; t is the relative thickness of the lift wing, representing the maximum dimensionless height between the upper arc and the lower chord of the lift wing, i.e., t = max[y u (x) - y d (x)], where y u (x) is the relative coordinate of the upper arc of the lift wing, and y d (x) is the relative coordinate of the lower chord; k a is an empirical constant, and the estimated value range is 0.15 to 0.2, k bis an empirical constant, and its estimated value range is 0.41 - 0.5;

[0074] wherein the lift-induced drag coefficient C DL is equal to the induced aerodynamic drag coefficient and the viscous pressure difference drag coefficient C Dn in engineering estimation, and the sum of C Di The calculation formula is: C DL = C Di + C Dn ;

[0075] Among them, (0.05λ - δ) / πλ in the formula is a correction term, which is usually determined by the wind tunnel test of a high-speed train with a lift wing assembly not less than 1:8 model or the test data of the actual vehicle line. δ is the correction coefficient of the high-speed train lift wing, and its estimated value range is 0.05 - 0.15 according to the degree of deviation of the lift wing from the optimal plane shape;

[0076] 4) Quantitative evaluation of the interference effect of the high-speed train lift wing:

[0077] 41) Calculation of the aerodynamic interference coefficient of the series lift wings on the roof of the high-speed train: The aerodynamic interference coefficient of the series lift wings on the roof of the high-speed train is characterized by the longitudinal aerodynamic drag F D of the series wings, and the calculation formula is as follows:

[0078]

[0079] In the formula, C d0 is the aerodynamic drag coefficient of a single set of lift wings on the roof. In engineering estimation, 1 set of layout conditions is taken; C d1 (i) is the direct interference coefficient of the i-th set of lift wings from the front to the back in the windward direction; A d is the longitudinal projected area of the lift wing device; n is the number of sets of series lift wings installed; ρ is the air density of the operating environment; v is the operating speed of the high-speed train with lift wings assembled;

[0080] 42) Calculation of the interference effect between the lift wing of the high-speed train with lift wings assembled and the train:

[0081] The interference effect between the lift wing of the high-speed train with lift wings assembled and the train is estimated by the overall aerodynamic co-lift coefficient of the two, and the calculation formula is as follows:

[0082] C Lt = (L ws + L sw ) / (0.5ρv 2 S0), where: L ws is the lift generated by the lift wing considering the adaptation of the high-speed train; L swThe lift generated by an adapted high-speed train considering a lift wing; S0 is the projected area of the lift wing in the vertical direction of the high-speed train;

[0083] Preferably, for the flat plate lift wing adapted to the high-speed train in step 11), due to the geometric twist of the high-speed train caused by the changes in the operating line conditions and the vehicle body motion state, there is an absolute zero-lift angle of attack α 0a , the value of which is equal to the angle between the zero-lift line and the zero-lift line of the middle wing section, and is calculated by the following formula:

[0084]

[0085] In the formula: F L is the lift of the lift wing; b(z) is the vertical chord length function of the lift wing; S is the area of the wing section of the lift wing on the longitudinal center plane of the train where the lift wing is located.

[0086] Reference Figure 2 , the effective installation space of the multi-unit lift wing in the transverse section is the area above the roof between the railway construction clearance and the vehicle clearance. The width (K) of the area is less than or equal to the transverse outer dimension of the train, and the height (H) of the area is less than the raised height of the pantograph of the high-speed train minus the safety height margin of 400 mm; the geometric design dimensions of the lift wing meet the space scale requirements of the railway construction clearance and the vehicle clearance in the transverse section; the transverse width (k) of the lift wing is less than or equal to the transverse outer dimension of the train and is 1600 - 2000 mm; the chord length (c) of the lift wing is equal to 0.5 - 1 times the transverse width (k) and is 800 - 2000 mm; the maximum thickness (tmax) of the center wing section of the lift wing is 250 - 400 mm, and the vertical distance (cx) from the position of the maximum thickness (tmax) to the leading edge end is 200 - 400 mm; the leading edge radius (r) of the lift wing is equal to 20 - 50 mm; the trailing edge angle (R2) of the lift wing is equal to 5 - 15 degrees.

[0087] Figure 3The pneumatic lift control body installed on the roof of a high-speed train supported by a lifting frame applicable to the method of the present invention can be used as a typical reference solution for the development and application of lift wings for high-speed trains with a speed of 400 km / h and the estimation of aerodynamic characteristics. The center wing section of the lift wing has a flat convex geometric structure with a convex upper surface and a flat lower surface, which is sequentially connected by 4 parts: the lower chord line, the leading edge, the upper arc line and the trailing edge. The lower chord line is a straight line, and the upper arc line is a multi-spline line. The overall structure of the lift wing smoothly transitions symmetrically to the left and right in the transverse direction along the center wing section. The lower end of the installation lifting frame is connected to the lift wing control mechanism part on the roof of the high-speed train, and the upper end is hinged and rotatably connected to the bottom of the lower arc surface of the lift wing in the longitudinal plane to meet the selection of multiple angles of attack of the lift wing. Among them, the effective installation space of the lift wing in the transverse section is the area above the roof between the railway construction limit and the vehicle limit. The width K of the area is less than or equal to the transverse external dimension of the train, and the height H of the area is less than the lifting height of the pantograph of the high-speed train minus the safety height margin of 400 mm. The geometric design dimensions of the lift wing meet the space scale requirements of the railway construction limit and the vehicle limit in the transverse section. The transverse width k of the lift wing is less than or equal to the transverse external dimension of the train, and is 1600 - 2000 mm. The chord length c of the lift wing is equal to 0.5 - 1 times the transverse width k, and is 800 - 2000 mm. The maximum thickness tmax of the center wing section of the lift wing is 250 - 400 mm, and the vertical distance cx from the position of the maximum thickness tmax to the leading edge end is 200 - 400 mm. The leading edge radius r of the lift wing is equal to 20 - 50 mm. The trailing edge angle R2 of the lift wing is equal to 5 - 15 degrees. The installation lifting frame is connected to the center position of the longitudinal chord line on the lower chord surface of the lift wing. When the lift wing is working, under the support and lifting control of the installation lifting frame, the normal working height h is 300 - 800 mm, and the normal working angle of attack R is 0 - 30 degrees. When the lift wing is working, it is preferably that the normal working height h is 400 mm, and the normal working angle of attack R1 is 20 degrees.

[0088] Reference Figure 3It is shown as follows: The first implementation mode of the lift wing: The lift wing is a zero-deflection flat-convex lift wing, and the wing profiles symmetrically arranged on the left and right sides of the lift wing transversely are geometrically consistent with the central wing profile. The chord length c of the zero-deflection flat-convex lift wing is 1200 mm, the transverse width k is 1800 mm, the leading-edge radius r is 25 mm, the trailing-edge angle R2 is 12 degrees, the vertical distance from the leading-edge end cx is 250 mm, and the corresponding maximum thickness tmax is 300 mm. The second implementation mode of the lift wing: The lift wing is a flat-convex lift wing with a deflection angle. The upper arc of the wing profile of the flat-convex lift wing with a deflection angle smoothly decreases and transitions symmetrically from the middle to the left and right sides. The vertical deflection angle R3 from the maximum thickness position of the central wing profile of the lift wing to the corresponding point of the maximum thickness position of the outermost wing profile is 5-10 degrees. The chord length c of the flat-convex lift wing with a deflection angle is 1200 mm, the transverse width k is 1800 mm, the leading-edge radius r is 25 mm, the trailing-edge angle R2 is 12 degrees, the vertical distance from the leading-edge end cx is 250 mm, the corresponding maximum thickness tmax is 300 mm, and the vertical deflection angle R3 is 12 degrees. The third implementation mode of the lift wing: The lift wing is a flat-convex lift wing with a sweep angle. The upper arc of the wing profile of the flat-convex lift wing with a sweep angle smoothly decreases and transitions symmetrically from the middle to the left and right sides. The vertical deflection angle R3 from the maximum thickness position of the central wing profile of the lift wing to the corresponding point of the maximum thickness position of the outermost wing profile is 5-10 degrees; in the horizontal projection plane, the leading edge is symmetrically provided with a forward sweep angle Rq on both sides to the rear, and the range is 75-90 degrees, and the trailing edge is symmetrically provided with a rear sweep angle Rh on both sides to the rear, and the range is 45-90 degrees. The chord length c of the flat-convex lift wing with a sweep angle is 1200 mm, the transverse width k is 1800 mm, the leading-edge radius r is 25 mm, the trailing-edge angle R2 is 12 degrees, the vertical distance from the leading-edge end cx is 250 mm, the corresponding maximum thickness tmax is 300 mm, the vertical deflection angle R3 is 12 degrees, the forward sweep angle Rq is 80 degrees, and the rear sweep angle Rh is 80 degrees.

[0089] Figure 4A lift wing device applicable to the method of the present invention mainly includes a lift wing, a lift wing mounting base and a control unit, and is characterized in that: it further includes a bidirectional double-acting telescopic hydraulic drive device, a linkage rod assembly, a double-acting hydraulic lifting device and a rotary drive assembly; the lift wing includes multi-stage lift wings symmetrically arranged on the left and right and connected in a nested manner, and is sequentially connected and fixed to the plunger shaft of the double-acting hydraulic lifting device through the lift wing mounting base, and under the combined drive of the bidirectional double-acting telescopic hydraulic drive device and the linkage rod assembly, realizes the synchronous left-right lateral telescopic movement of the multi-stage lift wings; the double-acting hydraulic lifting device drives the lift wing to move up and down through the plunger shaft, and at the same time realizes the rotation and self-locking of the lift wing device under the drive control of the rotary drive assembly. The front and rear longitudinal cross-sectional profile of the multi-stage lift wing is a streamlined closed structure surrounded by a bottom plate, a front side plate and a tail side plate, which is parallel at the bottom and convex at the top; the multi-stage lift wing includes a left first-stage lift wing, a left second-stage lift wing, a left third-stage lift wing, a right first-stage lift wing, a right second-stage lift wing and a right third-stage lift wing symmetrically arranged on the left and right and connected in a nested manner. When the nested lift wings of the multi-stage lift wing are deployed for work, the tail lengths of the lift wings at all levels change in a gradually shortening manner from the middle to both sides.

[0090] Figure 5 Another lift wing device applicable to the method of the present invention includes a telescopic wing and a lifting and pitching adjustment mechanism for adjusting the height and pitching angle of the telescopic wing in the vertical direction to provide lift or air resistance for the train; a rotating base provided at the bottom of the lifting and pitching adjustment mechanism for supporting the lifting and pitching adjustment mechanism; a rotating mechanism provided below the rotating base, and the rotating mechanism drives the rotating base to rotate, driving the telescopic wing to rotate to resist the lateral force of the crosswind; single actions or combined actions such as pitching, lifting, and rotating of the wing can be performed according to the actual operating environment and operating requirements of the train, and by controlling and adjusting the attitude of the wing, the flow state of the air flow above and below the wing is changed, and further the force exerted by the wing on the train is changed, so as to achieve the goal of regulating the operation and braking of the high-speed train.

[0091] It should be noted that the "front", "rear", "upper", "lower" and other directions or position relationships mentioned in this document are based on the position relationships shown in the drawings, and are only for the convenience of describing the technical solution and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation. Therefore, it cannot be understood as a limitation to the technical solution, and the connection relationship can refer to a direct connection relationship or an indirect connection relationship. The professional term symbols in this document are given corresponding marks and explanations in the order of appearance, and only explained once, and the meanings, explanations or descriptions represented by the same marked symbols appearing subsequently are equally applicable.

[0092] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. An engineering estimation method for the coordinated aerodynamic characteristics of a high-speed train lift wing and a wing vehicle, characterized by: The method takes a high-speed train equipped with a multi-unit lifting wing as a research object, and on the basis of basic theory, numerical simulation and experimental test, conducts a universal evaluation and general calculation of aerodynamic characteristics for the aerodynamic design selection of the lifting wing of the high-speed train and the key technical parameters of the coordinated layout optimization on the high-speed train, wherein the aerodynamic characteristics estimation content of the lifting wing of the high-speed train mainly includes the lift coefficient of the wing section and the lateral distribution characteristics along the train, the lift line characteristics and the drag characteristics; the estimation content of the coordinated aerodynamic characteristics of the wing-car combination mainly includes the aerodynamic interference effect of the high-speed train body on the lifting wing and the aerodynamic interference effect of the lifting wing on the inherent flow field of the high-speed train and the layout of the roof equipment and facilities; The multi-unit lift wing is a lift control body adapted for aerodynamic coordination of high-speed trains with a speed of 400 km / h or above. The overall structure of the lift wing has a symmetrical and smooth transition to the left and right sides along the central wing section. The lifting frame is movably connected to the lift wing control mechanism on the roof of the high-speed train by installing a lifting frame, so as to adapt to the selection of multiple angles of attack, multiple angles of rotation, and multiple lifting heights of the lift wing. The specific engineering estimation method for the coordinated aerodynamic characteristics of the lifting wing and wing vehicle of a high-speed train includes the following steps: 1) Engineering estimation of lift coefficient of high-speed train lift wing section and its lateral distribution characteristics along the train: When the high-speed train lifting wing is a straight wing with a large aspect ratio, the lift coefficient of the wing section is calculated using the lift line theory; when the high-speed train lifting wing is a lift control wing with a small aspect ratio or a lift control wing with a swept angle, the lift coefficient of the wing section is calculated using the lift surface theory; The lift coefficient of the high-speed train lift wing is equal to the sum of the basic lift coefficient and the additional lift coefficient in engineering estimation. The general calculation formula is: C L ′(z)=C L ' b (z)+C L ' a (z), where: C L '(z) is the lift coefficient of the high-speed train lift wing; C L ' b (z) is the basic lift coefficient of the high-speed train lift wing; C L ' a (z) is the additional lift coefficient of the high-speed train lift wing; 11) Determination of basic lift coefficient of lift wing: When the lift wing of the high-speed train is in a non-crosswind environment or the aerodynamic twisting effect of the lift wing caused by the line environment, the basic lift coefficient of the high-speed train is calculated according to the following formula: Where: C L ' b (z) is the basic lift coefficient of the high-speed train; is the lift line slope corresponding to the infinite length wing of the lift wing; is the vertical velocity potential function; α 0a The absolute zero lift angle of attack exists due to the geometric twist of the high-speed train caused by the running line conditions and the changes in the motion state of the car body; 12) Determination of the additional lift coefficient of the lift wing: The additional lift coefficient of the high-speed train lift wing is estimated by engineering experience based on the parameter characteristics of the elliptical lift wing under reference conditions. The calculation formula is as follows: Where: b0 is the chord length of the reference elliptical lift wing root; z is the vertical vector value; k is the total lateral length of the lift wing; 2) Determination of lift line characteristics of high-speed train lift wing: The lift line of the high-speed train lift wing is characterized by zero lift angle of attack, lift line slope and maximum lift coefficient, and the calculation formula is: Where: α is the angle of attack; α0 is the zero-lift angle of attack, and the calculated value is where α 0∞ is the angle of attack corresponding to the infinite length lift wing, η is the lift wing root-tip ratio; is the reference velocity potential function; is the lift line slope of the lift wing, and the calculation formula is as follows: Where: λ is the aspect ratio; χ 1 / 2 The sweep angle is 0.5 chord length; The maximum lift coefficient of the high-speed train lift wing passes through the maximum lift coefficient C of the middle wing section of the lift wing where the longitudinal center plane of the train is located. Lmax0 The maximum lift coefficient C of the wing section at the left and right ends of the high-speed train lift wing Lmax1 To make an engineering estimate, the calculation formula is: C Lmax =k s (C Lmax0 +C Lmax1 ) / 2; for the vertical lift wing arranged symmetrically on the roof of a high-speed train, the coefficient k is estimated s The range is 0.75 to 0.

85. For the lift wing with swept angle arranged symmetrically on the roof of a high-speed train, the coefficient k is estimated. s The range is 0.86 to 0.95; 3) Determination of aerodynamic drag characteristics of high-speed train lift wing: The aerodynamic drag coefficient C of the high-speed train lift wing D Engineering estimate is equal to zero lift aerodynamic drag coefficient C D0 and lift-induced drag coefficient C DL The sum is expressed as: C D =C D0 +C DL ; wherein the zero-lift aerodynamic drag coefficient C D0 The parameters of the average chord length of the high-speed train lift wing are used for calculation in engineering estimation, and the calculation formula is: C D0 =(2C F ) bav (1+0.1t+0.4t 2 ), In the formula, C F is the friction drag coefficient of the same lift wing chord length; t is the relative thickness of the lift wing, which represents the maximum dimensionless height between the upper arc line and the lower chord line of the lift wing, that is, t = max[y u (x)-y d (x)], where y u (x) is the relative coordinate of the arc line on the lift wing, y d (x) is the relative coordinate of the lower chord; k a is an empirical constant, and its estimated value range is 0.15~0.2, k b is an empirical constant, and its estimated value range is 0.41 to 0.5; The lift-induced drag coefficient C DL In engineering estimation, it is equal to the induced aerodynamic drag coefficient and the viscous pressure difference drag coefficient C Dn The sum of C Di The calculation formula is: DL =C Di +C Dn ; in, Where (0.05λ-δ) / πλ is the correction term, which is usually determined by wind tunnel tests of a model of a high-speed train equipped with a lift wing of no less than 1:8 or actual vehicle line test data. δ is the correction coefficient of the lift wing of the high-speed train. The estimated value range is 0.05 to 0.15 according to the degree to which the lift wing deviates from the optimal plane shape. 4) Quantitative evaluation of interference effect of lift wing of high-speed train: 41) Calculation of the aerodynamic interference coefficient of the tandem lift wing on the roof of a high-speed train: The aerodynamic interference coefficient of the tandem lift wing on the roof of a high-speed train is calculated by the longitudinal aerodynamic drag F D To characterize, the calculation formula is as follows: In the formula, C d0 is the aerodynamic drag coefficient of a single lift wing on the roof. One set of layout conditions is used in engineering estimation; C d1 (i) is the direct interference coefficient of the i-th set of lift wings from front to back in the upwind direction; A d is the longitudinal projection area of ​​the lift wing; n is the number of installation arrangements of the tandem lift wing; ρ is the air density of the operating environment; v is the operating speed of the high-speed train equipped with the lift wing; 42) Calculation of interference effect between lift wing and train of high-speed train equipped with lift wing: The interference effect between the lift wing and the train of the lift wing high-speed train is estimated by the overall aerodynamic synergy lift coefficient of the two, and the calculation formula is as follows: C Lt =(L ws +L sw ) / (0.5ρv 2 S0), where: L ws The lift generated by the lift wing to accommodate high-speed trains; L sw The lift generated by the adapted high-speed train to take into account the lift wing; S0 is the projection area of ​​the lift wing in the vertical direction of the high-speed train.

2. The method for estimating the coordinated aerodynamic characteristics of a high-speed train lift wing and a wing vehicle according to claim 1 is characterized by: In step 11), the flat lift wing adapted for high-speed trains corresponds to The absolute zero lift angle of attack α caused by the geometric torsion of the high-speed train due to the running line conditions and the changes in the body motion state 0a , which is equal to the angle between the zero lift line and the zero lift line of the middle wing section, is calculated by the following formula: Where: F L is the lift of the lift wing; b(z) is the vertical chord length function of the lift wing; S is the wing cross-sectional area of ​​the longitudinal center plane of the train where the lift wing is located.

3. The method for estimating the coordinated aerodynamic characteristics of a high-speed train lift wing and a wing vehicle according to claim 1 is characterized by: The effective installation space of the multi-unit lift wing in the transverse section is the area above the roof between the railway construction limit and the vehicle limit, the area width (K) is less than or equal to the transverse outer dimension of the train, and the area height (H) is less than the lifting height of the pantograph of the high-speed train minus the safety height margin of 400mm; the lift wing geometric design size meets the spatial scale requirements of the railway construction limit and the vehicle limit in the transverse section; the lift wing transverse width (k) is less than or equal to the transverse outer dimension of the train, which is 1600-2000mm; the lift wing chord length (c) is equal to 0.5-1 times the transverse width (k), which is 800-2000mm; the maximum thickness (tmax) of the central wing section of the lift wing is 250-400mm, and the vertical distance (cx) from the maximum thickness (tmax) position to the leading edge end is 200-400mm; the leading edge radius (r) of the lift wing is equal to 20-50mm; the trailing edge angle (R2) of the lift wing is equal to 5-15 degrees.

4. The method for estimating the coordinated aerodynamic characteristics of a high-speed train lift wing and a wing vehicle according to claim 1 is characterized by: The installation hoist is connected to the center position of the longitudinal chord line of the lower chord surface of the lift wing. When the lift wing is working, under the support and lifting control of the installation hoist, the normalized working height (h) is 300-800 mm, and the normalized working angle of attack (R) is 0-30 degrees.

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