EN 14067-6-2018 Railway applications - Aerodynamics - Part 6 Requirements and test procedures for cross wind assessment.pdf

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1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Railway applications - AerodynamicsPart 6: Requirements and test procedures for cross wind assessmentBS EN 14067-6:2018EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14067-6 July 2018 ICS 45.060.01 Supersedes EN 1

2、4067-6:2010English Version Railway applications - Aerodynamics - Part 6: Requirements and test procedures for cross wind assessment Applications ferroviaires - Arodynamique - Partie 6 : Exigences et procdures dessai pour lvaluation de la stabilit vis-vis des vents traversiers Bahnanwendungen - Aerod

3、ynamik - Teil 6: Anforderungen und Prfverfahren zur Bewertung von Seitenwind This European Standard was approved by CEN on 3 March 2018. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national

4、 standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version

5、 in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czec

6、h Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kin

7、gdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels 2018 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14

8、067-6:2018 ENational forewordThis British Standard is the UK implementation of EN 14067-6:2018. It supersedes BS EN 14067-6:2010, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee RAE/1/-/4, Railway Applications - Aerodynamics.A list of organizations rep

9、resented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2018 Published by BSI Standards Limited 2018ISBN 978 0

10、580 90719 7ICS 45.060.01Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2018.Amendments/corrigenda issued since publicationDate Text affectedBRITISH ST

11、ANDARDBS EN 14067-6:2018EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14067-6 July 2018 ICS 45.060.01 Supersedes EN 14067-6:2010English Version Railway applications - Aerodynamics - Part 6: Requirements and test procedures for cross wind assessment Applications ferroviaires - Arodynamique - P

12、artie 6 : Exigences et procdures dessai pour lvaluation de la stabilit vis-vis des vents traversiers Bahnanwendungen - Aerodynamik - Teil 6: Anforderungen und Prfverfahren zur Bewertung von Seitenwind This European Standard was approved by CEN on 3 March 2018. CEN members are bound to comply with th

13、e CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Managemen

14、t Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status

15、as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, N

16、etherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

17、2018 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14067-6:2018 EBS EN 14067-6:2018EN 14067-6:2018 (E) 2 Contents Page European foreword 5 Introduction 7 1 Scope 8 2 Normative references 8 3 Terms and definitions . 8 4 Symbols an

18、d abbreviations . 9 5 Methods and requirements to assess cross wind stability of vehicles 22 5.1 General 22 5.2 Applicability of cross wind methodologies for rolling stock assessment purposes . 23 5.3 Determination of aerodynamic coefficients 25 5.3.1 General 25 5.3.2 Predictive formula 25 5.3.3 Sim

19、ulations by Computational Fluid Dynamics (CFD) 26 5.3.4 Reduced-scale wind tunnel measurements 29 5.4 Determination of wheel unloading due to cross winds. 34 5.4.1 General 34 5.4.2 Simple method . 34 5.4.3 Advanced quasi-static method . 37 5.4.4 Time-dependent MBS method using a Chinese hat wind sce

20、nario . 40 5.5 Presentation form of characteristic wind curves (CWCs) 47 5.5.1 General 47 5.5.2 CWC presentation form for passenger vehicles and locomotives . 48 5.5.3 CWC presentation form for freight wagons . 49 5.6 Requirements . 50 5.6.1 Requirements for passenger vehicles and locomotives runnin

21、g at 250 km/h vmax 360 km/h . 50 5.6.2 Requirements for passenger vehicles and locomotives running 140 km/h 40: z0= 0,55 z14,3103per degree For 0 40: z1= 0,013 75 For 40: z1= 0 z22,2104per degree to the power of two 0 z32,1106per degree 0 z41,2 1 z51,2 1 fL=+0VEH03 075, ,LLfLwith L0= 25 m 1 1 fVEH1

22、0,75 1 A010 m2d03 m NOTE Factors z1, z2, z3 are referring to angles in degrees. 5.3.3 Simulations by Computational Fluid Dynamics (CFD) 5.3.3.1 General The chief purpose of applying CFD is to determine the set of aerodynamic loads appropriate for determining the mechanical stability of a critical ve

23、hicle. The aerodynamic loads needed for such a study are usually the side and lift forces along with the moments of roll, pitch and yaw. In addition, CFD provides a prediction of the velocity and pressure fields, and easily allows different configurations to be taken into account. The approach outli

24、ned here is similar to that recommended for reduced-scale wind tunnel measurements, see 5.3.4, in that a stationary train and a low turbulence block profile onset flow shall be used. The flow around the vehicle is usually subjected to the following characteristics; three-dimensionality, high Reynold

25、s number, turbulence, deceleration and acceleration, curved boundaries, separation, possible reattachment, recirculation and swirling properties. The proper solution of this aerodynamic problem can only be determined by DNS (Direct Numerical Simulation) of the Navier-Stokes formulae which in practic

26、e is strongly limited by computational resources. Approximate solutions may be achieved by turbulence modelling through approaches such as: LES (Large Eddy Simulation), DES (Detached Eddy Simulation), RANS (Reynolds Averaged Navier Stokes). The flow around a vehicle is inherently unsteady, and varie

27、s with the geometry and yaw angle. However, RANS methods are sufficiently accurate for the purpose of these investigations. A commonly applied method to check the steadiness of the flow is to confirm that the residuals are reduced by three to four orders of magnitude and the loads of interest have c

28、onverged with negligible cycling of the solution. BS EN 14067-6:2018EN 14067-6:2018 (E) 27 The chief challenge of CFD is the appropriate choice of an adequate combination of computational mesh, computational method and turbulence modelling. One advantage of CFD is that blockage effects can be minimi

29、zed by using a sufficiently large domain size without compromising the Reynolds number or Mach number. 5.3.3.2 Benchmark tests In order to demonstrate the appropriateness of the CFD approach, calculations shall be made for at least one specified benchmark vehicle (see 5.3.4.2 and Annex C), in a simi

30、lar fashion to that described for validating wind tunnel measurements in 5.3.4.2. The results from these calculations shall be compared to the benchmark values derived from wind tunnel measurements. The quality criteria defined in 5.3.4.2 shall be applied. 5.3.3.3 Vehicle model The representation of

31、 the test vehicle and adjacent vehicles models, as far as intercar-gaps, vehicles length and modelling accuracy are concerned, shall be according to that for wind tunnel measurements, see 5.3.4.8 and 5.3.4.9. Contact between the wheels and rail or ground may be simplified, e.g. by cutting the base o

32、f the wheel to avoid numerical singularities in the contact point. 5.3.3.4 Computational domain The model dimensions may either be at full scale or model scale. The latter may be advantageous from a practical viewpoint if results are compared with wind tunnel measurements at some point. The domain b

33、oundaries shall not interfere with the flow around the vehicle in a physically incorrect way. The requirements for blockage ratio shall be taken from 5.3.4.7. The computational domain shall extend in the streamwise direction relative to the vehicle of interest: at least 8 characteristic heights upst

34、ream and 16 characteristic heights downstream. The characteristic height is defined by the distance between the top of the train and the ground, e.g. when modelling an embankment this height is the height of the embankment including ballast and rail plus the height of the train. 5.3.3.5 Computationa

35、l mesh The mesh shall meet basic requirements concerning cell sizes adjacent to no-slip walls, appropriate for the selected computational method and turbulence model. Typical values for the dimensionless wall distance y+ for the first cell layer for RANS simulations are of the order of 1 for low-Rey

36、nolds number turbulence models and typically 30-150 for high-Reynolds number turbulence models. The mesh should capture regions of high pressure/velocity gradient such as: boundary layers, vortices, stagnation zones, recirculation cells, wakes, flow acceleration. The design of mesh for different yaw

37、 angle calculations should be kept as fixed as possible, in terms of the size and distribution of computational cells. The location and size of regions of relatively high resolution may have to be varied. A sufficient number of mesh nodes between the vehicle and boundaries shall be used. Mesh indepe

38、ndency for the vehicle under investigation shall be proven by changing the mesh resolution at least in regions of high gradients with two levels of mesh refinement as a minimum. The mesh resolution shall be different by a factor of 1,5 in each spatial direction in the regions where strong velocity g

39、radients have been found. The results of the three meshes shall show good agreement in both flow topology and force coefficients. The rolling moment coefficient around the lee rail shall have an accuracy of 3 % between the three refinements for yaw angles between 10 and 50. The largest of the obtain

40、ed values at each yaw angle shall be taken as the result. BS EN 14067-6:2018EN 14067-6:2018 (E) 28 5.3.3.6 Computational method The computational method shall be able to model the viscous, turbulent, unsteady, three-dimensional and strongly separated flows. However, steady methods may be used if the

41、 steadiness of the flow is evident. The majority of the methods are based on continuum theory governed by the momentum formulae (Navier-Stokes formulae), but methods based on kinetic gas theory (Lattice-Boltzmann formulae) may be used as well. 5.3.3.7 Turbulence modelling Turbulence models are engin

42、eering assumptions to predict turbulent stresses. These stresses emerge as a result of averaging or filtering of the nonlinear convection terms of the governing flow formulae. They may be regarded as an additional viscosity that for turbulent flows are sometimes several orders of magnitude larger th

43、an the molecular viscosity. However, no universal turbulence model exists. Calculations shall involve a sensitivity test, using the most appropriate turbulence models. If ambiguous results are obtained, wind tunnel measurements shall be used instead. Commonly used turbulence models are the k- and k-

44、 models. However, these models are known to produce excessive eddy viscosity which could lead to underestimation of recirculation regions and suppression of flow separation. Therefore, such models should be used with care. Alternative approaches exist that may require more computational effort and a

45、re part of ongoing research activities. 5.3.3.8 Boundary conditions The onset wind profile just upstream of the vehicle of interest shall have a uniform, i.e. block profile, to agree with the specifications in 5.3.4.4 for wind tunnel measurements. The outlet boundary condition shall be appropriate f

46、or the train configuration under consideration e.g. a constant pressure or conservation of mass boundary condition. The surfaces of the train shall be treated as no-slip walls. The ground may be either stationary or moving with a relative velocity corresponding to the vehicle speed. The top and late

47、ral plane boundary conditions shall be appropriate for the train and yaw angle configuration under investigation. 5.3.3.9 Reynolds number The Reynolds number “Re” is based on the flow speed at the onset boundary and calculated with a characteristic length of 3 m (at full scale) and shall be no lower than that specified for the wind tunnel measurements in 5.3.4.5. 5.3.3.10 Test programme requirement See 5.3.4.11 and 5.3.4.12. 5.3.3.11 Data interpolation See 5.3.4.13. 5.3.3.12 Documentation Conformity with all requirements defined in 5.3.3 shall be documented. BS EN 14067-6:2018