Ingénierie et architecture système, Projets complexes et multidisciplinaires, ERTMS, Interopérabilité, Exploitation, Maintenance



TNT, acronym of Tunnel Nets & Trains, is a software that was specifically developed for the numerical simulation of unsteady compressible fluid-flows in tunnel networks.

TNT deals with networks of high complexity that include pressure relief ducts, ventilation shafts and multiple connections, either mutual, or open to the atmosphere.

Example of underground tunnel network solved with TNT

TNT solves the one-dimensional form of the compressible Navier-Stokes equations (conservation of mass, momentum and energy) including buoyancy effects. Additional conservation equations are solved for the simulation of reactive flows and to account for humidity variations.

TNT computes at any location and any time physical fields such as pressure, density, velocity, species concentration, humidity, and temperature (in both the fluid and the solid walls of the network) according to:

  • the motion of an arbitrary number of solid objects, such as low- and high-speed trains, road vehicles and pedestrians;
  • the development of fires, either stationary or attached to the moving solid objects;
  • the operation of complex ventilation systems, including shafts, jetfans, air-conditioning units and any electro-mechanical device;
  • the evolution of climate conditions at the open ends of the network, which are defined by meteorological data or weather forecasts;
  • the thermal conditions in the ground surrounding the network.