Roof Rider Development:
Product development of drag reduction devices seeking to reduce aerodynamic drag in trains.
In this project we are working in unison with Deflect LLC, a small American startup that is developing new devices to reduce aerodynamic drag for passenger and freight trains. (For more information visit RoofRider.
Aerodynamic drag can account for more than half of the energy required to move passenger trains. Some of the largest sources of drag for both passenger and freight trains are inter-car gaps where air can enter the gap and strike the front face of trailing cars, raising the amount of energy that is required to move the train. Earlier results have shown that a patent pending aerodynamic deflector called the “RoofRider” can reduce this drag by directing air over the gap and reducing the force that hits the next car. This deflector is less than an inch in height and placed on the roof adjacent to the inter-car gap using an adhesive.
Initial development of the RoofRide was performed in conjunction with the University of Birmingham at the Birmingham Centre of Railway Research and Education located in the UK, one of the world’s top locations for the study of aerodynamic drag on trains. CFD studies on an ICE2 passenger train reinforced with physical moving model scale testing gave total drag reduction estimates for the RoofRider of 4.3% in headwinds and 5.5% in crosswinds.
Drag savings of around 8% in headwinds and 1% in crosswinds have also been shown on double stacked Intermodal trains. In both cases these reductions in drag should reduce energy consumption by more than 1%.
​
In this new phase of Deflect LLC, the young startup is looking to bring the development of the deflector in house and VFluid Technology is assisting them in the development of the product from inception until release. VFluid Technology has been working for the past few months in creating a long-term development plan, generating CAD models, CFD models and automated procedures for the development of the RoofRider in an efficient manner.
The development process will entail a mixture of existing experimental and simulation data analysis, generation of new CFD models and the design, manufacture and management of new wind tunnel tests. The core development will be carried using CFD simulations and the chosen software was Siemens StarCCM+. This software provides a great balance between performance, costs and delivery times frames (for more information listen to the Siemens podcast with Deflect LLC. The automated process entails the use of a Python master code which then deploys the CFD simulation which is controlled by a Java script, gathers the results data into a database and performs the desired post-processing using Paraview.