The freight rail industry is essential to the US infrastructure and there is significant motivation to improve its efficiency. The aerodynamic drag associated with transport of commodities by rail is becoming increasingly important as the cost of diesel fuel increases. For intermodal railcars a significant amount of aerodynamic drag is a result of the large distance between containers that often occurs and the resulting pressure drag resulting from the separated flow that results due to their non-streamlined shape. This thesis reports on research that has been done to characterize the aerodynamic drag on intermodal train builds and allow their builds to be optimized for fuel efficiency. Data was obtained through wind tunnel testing of G-scale (1/29) models. Drag on these models was measured using a system of isolated load cell balances and the wind tunnel speed was varied from 20 to 100 mph. Several common intermodal scenarios were explored and the aerodynamic drag for each was characterized. These scenarios were the partial loading of containers on rail cars, the influence of the gap between containers, the use of a streamlined container near the front of the train, and the inclusion of semi-trailers on railcars. For each case multiple build configurations were tested and the drag results were compared to determine the optimal build for each scenario.



College and Department

Ira A. Fulton College of Engineering and Technology; Mechanical Engineering



Date Submitted


Document Type





aerodynamics, railcars, intermodal, wind tunnel, train