The picture shows the time-averaged flow structures in the wake of a simplified ICE2 train. To understand the flow around a vehicle in fundamental terms is the key to reduce the aerodynamic drag and thereby also the energy consumption.
The aim of the project is to investigate how energy can be saved for regional and freight trains by improving trains' aerodynamic properties. Running resistance of trains consist of rolling resistance which is proportional to trains velocity and aerodynamic drag which is proportional to the squared speed. Even though freight trains travels at speeds slower than regional and much slower than high speed train (HST), considerable energy can be saved by improving the aerodynamics.
The flow around a train body is a so called bluff body flow, which means that it is dominated by flow separation that creates large vortex structures. These vortices decreases the air pressure which increases the drag. The project will study add-on devices capable to improve energy efficiency of existing regional and freight trains. Add-on devices such as side skirts, enclosing of inter-car gaps, placement of so called vortex generators, deflectors and fins at the front of the rail cars will be studied using numerical methods. The aim of the project is to proposse concrete improvements of energy efficiency of existing trains in Sweden.