Experimental characterization of a road tunnel jet fan by direct measurement of the velocity components at the inflow and out flow section

Axial jet fans installed at the ceiling are worldwide diffuse devices for longitudinal ventilation control in road tunnels underordinary operating conditions and also for smoke control under fire conditions.An experimental characterization of one of the jet fans actually operating inside the tunnel Mont Blanc has been carried out bymeans of a multi-axial hot wire technique. Inflow and outflow instantaneous axial, radial and tangential velocity profiles havebeen measured in still air at the nominal speed of rotation of the fan. Time averaged velocity profiles and turbulent kineticenergy profile have been derived from instantaneous data. In the paper, details of the testing procedure, the experimental setup,the collected data and the post-processed profiles are reported.