Montgomery Tunnel ventilation upgrades double thrust

14 August 2019

Belgium – MoJet outlet silencers have doubled the in-tunnel thrust of the jet fans at the Montgomery Tunnel in Brussels.

Measurements were carried out by the Université Libre de Bruxelles (ULB) on the 630mm internal diameter unidirectional jetfans, supplied by Flakt Woods. Attenuators incorporating MoJet technology were fitted in an attempt to improve the arduous installation conditions. These existed because the jet fans were installed in the tunnel corner, where high shear stress is generated between the jet and the tunnel wall, and the soffit, with a conventional jet fan.

Mosen’s Fathi Tarada said, “The original idea was to test the MoJet in a road tunnel, and Bruxelles Mobilité agreed to make the Montgomery Tunnel available for this purpose. Based on the positive results of the CFD analysis, Bruxelles Mobilité ordered the MoJets from Flakt Woods, and the MoJets are now permanently installed in the Montgomery Tunnel.

“The results of the tests and the background research will be presented at the forthcoming 18th International Symposium on Aerodynamics, Ventilation & Fire in Tunnels in Athens, Greece, being held on 25-27 September 2019. Notably, the measured tunnel air velocity from 3 MoJets was nearly as high as that obtained from 10 conventional jet fans.”