13th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
The Channel Tunnel is made up of 2 long railway tunnels of about 50 km long and connected every 250 m by 2 m diameter pipes. These pipes, called piston relief ducts, allow the air pushed by a train to go from one tunnel to another to limit the piston effect due to the trains. Pressure drop devices are placed in the ducts to limit the flow speed. Eurotunnel is studying the possibility to replace these devices with turbines. These turbines must operate with flows alternatively in both directions, while keeping the same rotation direction. This study focused on the design and simulation of self-rectifying turbines adapted to the Channel Tunnel ducts. It is therefore proposed here to evaluate the adaptation of the various existing concepts by means of one-dimensional calculations and 2D numerical simulations. Two types of turbines are studied: Wells and Impulse turbines. A preliminary design of the two types of turbines is proposed and their performances are discussed.