EN 14067-1: Railway Applications – Aerodynamics – Part 1: Symbols and Units

What is EN 14067-1?

EN 14067-1 serves as the linguistic and mathematical cornerstone for the Aerodynamics of railway systems. In the development of High-Speed Rail, aerodynamic forces become the dominant factor affecting Operational Safety, energy consumption, and passenger comfort.

This part of the standard does not set safety limits itself; instead, it provides a harmonized set of Symbols and Units. This ensures that engineers across Europe use the same variables when calculating the drag of Rolling Stock or the pressure pulses inside a tunnel.

Scope and Definitions

The standard covers all aerodynamic phenomena related to the track-train interface. It defines the precise meaning of terms that are often used loosely in general engineering:

• Slipstream: The air flow induced by the passage of the train, which can affect people on platforms.
• Head Pressure Pulse: The sudden change in pressure at the front of the train as it passes a fixed point or another train.
• Cross-Wind Stability: The resistance of the vehicle against overturning or derailment due to lateral wind forces.
• Running Resistance: The portion of energy loss attributed to air friction and pressure drag.

Standardized Symbols and Physical Quantities

To ensure Interoperability in technical documentation, EN 14067-1 mandates specific symbols for common aerodynamic variables:

• $c_x$: Drag coefficient (longitudinal).
• $c_z$: Lift coefficient (vertical).
• $p$: Static pressure.
• $v_{tr}$: Train velocity relative to the track.
• $\rho$: Air density (standardized at 1.225 kg/m³ for calculations).

Impact on Design and Testing

By establishing these Technical Delivery Conditions for data, EN 14067-1 allows for:

• Computational Fluid Dynamics (CFD): Standardized input/output parameters for simulation software.
• Wind Tunnel Testing: Uniform reporting of results from different facilities.
• Infrastructure Management: Providing consistent data to designers of tunnels, noise barriers, and platform shelters.

Structure of the EN 14067 Series