NUMSTA(R) (WIPO No. 1115910)
NUMSTA(R) stands for NUMerical Simulation of Tunnel Aerodynamics. It is a simulation tool for flow phenomena in complex tunnel networks induced by trains traveling at high speed and has been developed in the context of the SwissMetro project (Rudolf, Alexander (1998). Simulation of compressible flow in tunnel systems induced by trains traveling at high speed. PhD thesis no. 1806. Lausanne: EPFL). It uses the Euler Equations with source terms for mass, momentum and energy transfer to account for the non-linear wave propagation in tunnel networks considering vehicles, tunnel networks and active components such as fans and dampers.
By using a 2nd order explicit numerical scheme on the conservative formulation of the Euler Equations, it allows to simulate complex flow and traffic scenarios (chocking, vehicles crossing, variable geometry, fans, dampers, …). It offers an alternative to the MoC (method of characteristics) codes that were customary up to that point based (e.g. ThermoTun, TTN MottMacDonald, The code from TU Vienna for DB), which were first developed in the late 60s and 70s. Quasi-compressible codes such as SES (USA) or Equa Tunnel can also be replaced by NUMSTA.
NUMSTA(R) uses a conservative upwind discretization method based on the unsteady and compressible Euler equations. It allows highly precise calculations of the tunnel aerodynamics of high-speed trains with encounter journeys, heat transfer, sound transmission and much more.
Since then, it has been used by train manufacturers and engineering consultancies in a number of high ranking projects.
NUMSTA(R) is continuously updated to account for new project requirements.
With respect to its validation:
NUMSTA(R) has been used intensively to predict the power requirement for the SwissMetro main project (1993-1998) and to define the required tunnel diameter as well as to describe the flow phenomena of the first high speed tube transportation system in a partial vacuum.
NUMSTA(R) was developed as part of the Swissmetro main study 1993-1998 as a dissertation at EPFL (thesis no. 1806 from 1998). The development took place under the guidance of top scientists in Switzerland and international experts. In particular, Prof. P.A. Monkewitz (EPFL), Prof. A. Vardy (Univ. Dundee, author of ThermoTun) as members of the expert committee for this work or as the specialist of Swissmetro Alan Weathe-rill (BG Lausanne) and Dr. Alberto Turi (Elektrowatt Zurich).
NUMSTA(R) was discussed in chap. 6 of the EPFL dissertation no. 1806 from 1998 validated by comparative calculations with Thermotun and measurements. It has since been bought by the world’s largest train manufacturer, Bombardier Transportation, and the ILF for such calculations and used commercially. Reference projects include: Swissmetro, Arlberg railway tunnel, Eppenberg tunnel, TransRUN Neuchâtel, Follobanen Norway, Wiener Linien, TEN-T Bratislava, Gotthard railway tunnel offer phase, comparative calculations on the Lötschberg tunnel, Brüttener tunnel, standard cross-sections of the DB.