The current interoperability approval process for new High Speed and Conventional railway vehicles in Europe is a very long and costly process. The European Railway Agency (ERA) is charged with the development of new and future Technical Specifications for Interoperability (TSIs), which provide common regulations for the authorisation of the placing into service of new vehicles. TSIs will provide a safe and technically-compatible railway system for Europe by specifying requirements for all relevant technical aspects. However, they will not directly eliminate the burdens that currently affect the railway industry and the railway undertakings regarding new vehicle approval on each national network in Europe.
TSIs are a set of common minimum requirements and therefore not optimal for every network administrator and/or railway undertaking. Placing in service a new vehicle, even if compliant with TSIs, still requires network approval by each National Safety Authority(NSA) responsible for the Member State in which the vehicle is to be operated.
In addition to the handicaps mentioned above, it is important to take into account the lack of compatibility of the national assessment methods. Therefore it is often requested by the Member States to repeat specific tests for homologation that are analogous to those tests already performed in other countries. At present a full harmonisation of the assessment methods required does not exist, although the evolution of new and expanded European standards is helping to close the gap.
AeroTrain will help meet the business scenarios listed in the ERRAC (SRRA 2002 and 2007) by aiding the spread of European homologation and acceptance procedures to speed up interoperable product approvals while squeezing out risk through improved safety management. In the field of aerodynamics a recent European standard (EN) focuses on common definitions and descriptions of the aerodynamic phenomena and measurement procedures. Due to its application for all types of rail traffic it has not converged yet to one method per phenomenon but allows variations arising from national rules. The focus of the project is therefore on using the TSI route to consolidate the methodologies allowing the free exchange of certification data.
The network approval of multi-system vehicles is a key subject that can and must be addressed in order to provide a competitive railway system within Europe. Therefore, the importance of AeroTRAIN, as it will contribute to the practical implementatio
The overall goal of the project AEROTRAIN is to promote interoperable rail traffic in Europe by reducing costs and time of certification and closing "open points" in the TSI's. It will be achieved by the following high-level objectives:
- address HS & CR TSI's that effectively work to harmonise European and national standards on aerodynamics to reduce costs and time of certification;
- reduce costs and time of certification by replacing existing cross wind and slipstream tests with new alternatives without reducing safety;
- reduce costs of certification by introducing virtual testing as far as it can be validated for head pressure pulse loads and crosswind aerodynamic loads. This will allow in the long term the use of more controlled environmental testing conditions which will increase safety and enable more realistic conditions for crosswind safety assessment to be investigated, reducing uncertainty and thereby avoiding unnecessary and costly infrastructure measures. For crosswind it includes both more realistic wind scenarios as well as more realistic modelling of the train on different infrastructure as embankments and viaducts;
- close "open points" in the HS and CRTSI's. Derive limit values and where necessary newcertification procedures. Introduction of limits for aerodynamic loads on the ballast track will have the added effect of ensuring that the higher-speed trains for the future will be more streamlined with regard to the under-floor regions, which will promote more energy-efficient trains.
Technical objectives and expected results:
- Slip stream effects: replace two test procedures with one at a test site that is easily accessible in all countries. From this will be derived:
- transfer functions from the ballasted straight track conditions to that of a platform;
- a specification of a new test procedure for TSI;
- the influence of single vehicles in a train to support CR TSI.
- Replace the current wind tunnel evaluation configurations of a train on a 6m embankment or flat ground with the prEN14067-6:2009 agreed configuration using ballast and rails for the certification of HS and CR vehicles according to the TSIs. Measure aerodynamic coefficients and apply vehicle dynamic simulations to compute limiting wind curves for most sensitiv
On the basis of the requirements for the new CR TSI and revision of HS TSI, opportunities to reduce certification costs and, where it is seen that virtual certification could be introduced, it is decided to focus the study on five main aspects of rolling stock aerodynamics that are or need to be subject to certification. Hence the Work Program of the project is organised around five technical Work Packages:
Open Air-Pressure Pulse:
- to develop a significant database about the open air pressure pulse by combining:
- existing GB databases on air pressure pulse;
- existing or future continental databases corresponding toTSI / EN requests.
Aerodynamic Loads on Tracks - to define and agree on:
- a standard specification for a measurement technique which captures the basic parameters of the ballast pick-up phenomenon;
- a standard track on which trains should be tested;a standard post-processing procedure for the measured data;
- a formulation of a needed TSI certification criterion.
- to close a TSI open point by delivering a limit criteria for crosswinds (Reference Characteristic Wind Curves) to CR RSTTSI and for Class 2 trains of HS RST TSI on the prEN14067-6:2009 single track with ballast and rails standard configuration;
- to derive Reference Characteristic Wind Curves and limit criteria for class 1 trains of HS RST TSI on the prEN14067-6:2009 single track with ballast and rails standard configuration. This would lead to a reduction in the costs of certification by considering, instead of
The project will bring a procedure for virtual certification of head pressure pulse valid for streamlined and non-streamlined trains, including the applicability of inviscid panel methods, and a verification that the maximum peak-to-peak pressure change occurs at the head of the train.
AeroTRAIN will establish common vehicle requirements to derive dimensioning guidelines for CR RST with respect to aerodynamic loads in tunnels, and set up a TSI criterion regarding micro-pressure waves (MPW) for interoperable trains to limit MPW effects in tunnels
Expected results on slip stream effects are the development of a transfer function which will enable measurements made at one location (e.g. at the trackside) to be related to those at a different location (e.g. on the platform); and a reduction in the technical requirements concerning the evaluation of slipstream velocities and hence an increase in the integration of rail transport activities across the EU.
The AeroTRAIN project will introduce:
- Limit Characteristic Wind Curves for Conventional Rail TSI and Class 2 High Speed trains;
- Limit Characteristic Wind Curves for Class 1 High Speed trains based on reference trains;
- Range of application of CFD methods and the corresponding procedure for assessment of crosswind aerodynamic load;
- An appropriate test procedure for crosswind aerodynamic load with more realistic conditions (train movement and embankment) and limitations of CFD methods for the corresponding configuration.
The main innovation brought by AeroTRAIN with regards to aerodynamic loads on tracks are the following:
- A measurement technique to assess the aerodynamic load in relation to the risk of ballast pick-up;
- A measurement of the aerodynamic load on track by different high speed trains with a common measurement procedure;
- A robust measurement and post processing procedure which captures the basic parameters of the ballast pick-up phenomenon suitable for certification;
- A standard track conditions to measure on;
- A limit criterion for TSI.
Innovating for the future: A European Transport Research and Innovation Policy