When trains travel through tunnels, they generate pressure waves that travel along the tunnels and are reflected back as a compression or rarefaction wave, depending on the type of obstacle that they encounter (e.g. portal, shaft, train). The pressure waves caused by single or multiple train movements in tunnels can create aural discomfort for passengers in unsealed coaches, or even structural failure for vulnerable parts of trains (e.g. window frames) or tunnel-mounted equipment. Issues related to pressure pulses can occur due to high-speed rail operation within tunnels (250 km\/h or greater), high blockage ratios within tunnels (including the relining of existing tunnels), and train crossings within tunnels.<\/p>\n
Mosen employs a validated one-dimensional tunnel network solver to model rail tunnel aerodynamics. This software allows us to model all relevant aspects of the tunnel infrastructure and train traffic, and to provide robust predictions of the pressure pulses within train coaches and in the tunnels. We have successfully employed this methodology for a range of projects, including the HSL Zuid tunnels in the Netherlands, and several rail tunnels in London.<\/p>\n