ROOFCONTROL

Low in fossil fuel consumption and CO₂ emissions, the rail industry is committed to sustainable development. The public community, the rail manufacturer's customer, assigns significant weight to the train's fuel consumption criterion. This is easy to justify, given that 75% of total costs are linked to train consumption and maintenance. In the context of railway aerodynamics, one of the major issues is the development of environmentally-friendly solutions for the cooling of roof-mounted equipment, requiring as little maintenance as possible. One potential avenue of research is based on forced convection cooling, which relies on the movement of external fluid through the equipment as the train moves. This requires information on the dynamic behavior of the flow in the vicinity of the equipment. These various items of equipment (cab or car air-conditioning units, brake rheostats, traction units, power converters, etc.) need to be correctly supplied with air and efficiently cooled. The aim of this project is to gain a better understanding of train roof airflows, and to optimize the flow for cooling heat-sensitive roof components. From the perspective of flow control with the aim of cooling certain so-called "thermally dead" zones, we looked at the dynamics of flows in the vicinity of equipment, and then addressed the phenomenon of potentially induced hydrodynamic oscillation, paying particular attention to cases of asymmetries.