Aerodynamics research

The aerodynamics research team within the Department of Civil Engineering have developed expertise in a wide range of aerodynamic issues that affect both network and vehicle operations.

In the design of modern trains a range of aerodynamic effects must be considered which includes the effects of aerodynamic drag on fuel consumption; unpleasant pressure variations for passengers in tunnels, the stability of trains in high winds; the effect of transient pressures and slipstreams on passing trains and passengers and trackside workers; the lift-off of ballast beneath trains; and the occurrence of micro-pressure waves (sonic booms) at the exit of long tunnels. The group has the expertise and experience to study these phenomena in a variety of ways: at full scale, using on-train and on-track measurements; at model scale using wind tunnel and moving model rig measurements; and through the use of Computational Fluid Dynamics. In particular the group has been at the forefront of development of moving model tests using the TRAIN Rig and is unique in being able to offer this breadth of expertise to the rail industry


Extreme wind effects and climate change are central to the work of the team and link closely with the work in the Environment theme of the Railway Centre. Aerodynamics links these factors with the operation of vehicles through dynamic train modelling and cross wind simulation. Safety and reliability of vehicles in such extreme conditions is becoming more critical with the demand for higher operating speeds and lower vehicle weight. The safety of passengers, trackside workers and the damage to network infrastructure caused by high-speed vehicle slipstreams are also key themes of the team’s work. Such concerns have been highlighted by recent events and the team works closely with industry to identify the key factors that are contributing to these issues. There is also an increasing awareness of the need to understand the aerodynamic interaction between vehicles, such as when vehicle pass each other at speed, and the vehicle-infrastructure interaction, such as in tunnels. Such interactions can cause discomfort for passengers as well as damage to vehicles or infrastructure thereby increasing maintenance costs.The aerodynamics research team within the Department of Civil Engineering have developed expertise in a wide range of aerodynamic issues that affect both network and vehicle operations.


The group has expertise in full scale measurements, physical model measurements and the use of computational fluid dynamics. For full scale measurements a large range of velocity, pressure and force measurement devices are available and the group has carried out measurements of pressures, slipstream and wake velocities and forces on trackside structures. For model scale experiments a large environmental wind tunnel is available (with a 2.5m square cross section) and the group own and operate the large moving model TRAIN Rig, formerly owned by Delta Rail, which is housed in Derby. For CFD calculations the group uses the University multi-processor BlueBear facility, mainly for running LES (Large Eddy Simulation) calculations.

Recent and current projects

This EU grant included 20 partners and was a major, 3-year project to investigate a wide range of aerodynamic issues for codification purposes. The group worked on slipstreams, crosswind effects and tunnel aerodynamics.

Freight train aerodynamics
PhD studentship to use the TRAIN Rig on freight trains.

Measurements and risk analysis of tunnel pressures on Midland Main Line
This project, with Network Rail, used on-train measurements of pressure transients to enable speed limits on the line to be raised.

Measurements of train slipstreams for overhead electrification train
Another Network Rail project for trackside measurements on Western Main Line to assess working conditions as trains pass at high speed.

Development of Network Rail wind modelling system
This project, supported by RSSB, is for the development of methodology and algorithms for an extensive series of Meteorological monitoring sites installed by Network Rail.

Measurement of wind loading on trackside structures
Funded by RSSB, TRAIN Rig measurements of forces on platforms, canopies, hoardings and other trackside structures by a variety of trains.

Measurement of train aerodynamic phenomena in operational conditions
On-train, trackside, wind tunnel, TRAIN Rig and CFD measurements in a large scale comparative project.

Train underbody flow
This EPSRC project carried out proof-of-concept measurements on TRAIN Rig.

Aerodynamic measurements for HS2
Phases 1 and 2: TRAIN Rig measurements for HS2 – train passing pressures, tunnel aerodynamics; sonic booms. Further projects are anticipated in the future.

Track Systems For High Speed Railways: Getting It Right
This 3-year EPSRC project is led by University of Southampton to carry out TRAIN Rig measurements of underbody flow to investigate the ballast flight problem.


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