An investigation of train drag reduction using sub-boundary layer vortex generators on a simplified intermodal well car geometry
Date
Authors
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Abstract
Railroad companies in the United States spent about $6.6 billion on diesel to move
freight in 2015. One way to save money and reduce fuel consumption is to reduce
the drag on the train. With the length of trains in the United States the drag due
to the gaps between cars in the train is substantial. To reduce the drag between cars
the intermodal well car was investigated. These cars carry intermodal containers often
stacked two high. There were 12.2 million intermodal containers shipped in 2015, making
the intermodal well car one of the most common cars in use. To avoid the need for
major structural changes to the intermodal container wishbone vortex generators were
investigated. Using steady Reynolds-Averaged Navier-Stokes simulations the flow field
around a train consisting of a scaled and simplified locomotive and two intermodal cars
was investigated. Sub-boundary layer vortex generators were then added to this model
in two configurations. The first configuration added vortex generators to the rear of the
intermodal cars, whereas the second configuration added vortex generators to both the
front and rear of the intermodal cars. The vortex generators were sized according to two
different boundary layer heights. The first height was found using flat plate turbulent
boundary layer theory. The second used the boundary layer developed at the end of the
first intermodal car. The addition of the smaller vortex generator showed a 2% drag
reduction. While this reduction is close to the minimum accuracy of the simulation, the
change in the drag on each car shows that further study is necessary to truly evaluate
these devices. The larger vortex generators on the other hand show a 12% increase in
the drag of the train.