Ground Vehicle Facility
When a high-speed train enters confined areas (single bore tunnels and stations), transient pressure waves are generated and propagate through the tunnel, affecting the passenger's comfort. This facility has been designed to study the transient pressure waves and to investigate solutions to reduce them.
The facility is a scaled model (1:87) designed to satisfy dynamic and geometric similarity.
The launcher based on crossbow technology, provides the energy required for propelling the train model at high speed (up to 150 km/h). The model slides on paired steel wires and enters a six meters long tunnel. The blockage ratio is equal to 0.15. Apertures located along the first part of the tunnel (up to 1.2 m from its entrance) allow the insertion of fast-response pressure transducers for measurements of static pressure fluctuations on the internal surface of the tunnel and of hot wire probes for measurements of velocity fluctuations in the annulus between the train model and the tunnel. Static pressure and flow velocity fluctuations due to the train passage can be measured for several geometrical configurations of the vehicle (i.e., conic-shaped noses, train's length) and of the tunnel (i.e., flared entry portals, airshafts…).