Snow is a major problem for all rail vehicles. The reasons for this are multifaceted. They range from reduced visibility and snow entering through ventilation openings—where it can melt on electrical systems and lead to short circuits—to iced-up tracks and points. Particularly in the latter case, safe rail transport is no longer possible. For this reason, points have heaters intended to melt the ice in the shortest possible time.
In order to obtain more information about the internal, invisible processes in addition to infrared measurements, FlowMotion was commissioned to simulate them. To this end, Computational Fluid Dynamics (CFD) simulations were performed. Not only were all components of a set of points modelled—such as the rail profile, sleepers, subgrade, slide plates, electric heater, and various ice blocks—but all heat transfer mechanisms, such as heat conduction, thermal radiation, and free convection, were also simulated. Modelling the ice melting process was a particular challenge.
The very high information density of the simulations proved to be a great advantage in precisely understanding the heat flows inside the points and their dependence on the thermal properties of the various components and environmental conditions. Therefore, a multitude of variants were calculated and the melting time determined.
It became apparent that a reduction in melting time could only be accomplished with a very high electrical output. However, this high electrical output also leads to high temperatures in the rail body, which can not only cause track deformation but also pose a threat to flora and fauna.
With the help of the simulation results, it was possible to find the most optimal compromise to ensure safe rail transport.
