Aerodynamic Forces in Intermodal Container Trains: A Study on the Effect of Wagon Position on Container Drag

Aerodynamic forces have a crucial role in the safe and efficient operation of freight trains. In particular, the drag of intermodal container trains is the focus of a considerable research effort because of its direct impact on the energy consumption and greenhouse gasses emissions of these the freight rail sector. The drag of containers in an intermodal container train can be affected by the proximity to the extremes of the train, among other factors. This means that the results obtained on one container train cannot be safely generalized to the other containers in a long intermodal container train, unless independence from these effects is established. Numerical simulations have been run on train consists of different length to assess the minimum number of wagons necessary to ensure independence form proximity to the extremes of the train. The drag coefficients on the containers are presented, demonstrating that at least nine wagons should be simulated to achieve this condition for the fourth and fifth wagon.