NUMSTA(R) (WIPO No. 1115910)
NUMSTA(R) stands for NUMerical Simulation of Tunnel Aerodynamics. It is a simulation tool for calculating the non-linear wave propagation in complex tunnel networks, taking into account high-speed trains, encounters, heat transfer, supersonic flow, fans, dampers and much more. It 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.
NUMSTA(R) uses a 2nd order upwind discretization method of the conservative, unsteady and compressible Euler equations with variable cross-section and source terms for mass, momentum and energy transfer. It allows the simultaneous consideration of a large number of parameters for tunnel aerodynamics and tunnel ventilation.
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(R).
NUMSTA(R) was used intensively to calculate the performance curve for the SwissMetro during the main project (1993-1998), to define the required tunnel diameter and to describe the flow phenomena of the first high-speed train in partial vacuum.
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) was developed as part of the Swissmetro main study 1993-1998 within the frame of 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) and the specialists of Swissmetro Alan Weatherill (BG Lausanne) and Dr. Alberto Turi (Elektrowatt Zurich) acted as scientific advisors and members of the expert committee for this work.
The validation of NUMSTA(R) was discussed in chap. 6 of the EPFL dissertation no. 1806 from 1998, where its results are compared with Thermotun and measurements. It has then been used commercially by Bombardier Transportation and ILF. 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.