Multi-scale Coupling Analysis of Partial Transverse Ventilation System in an Underground Road Tunnel

摘要

A real underground road tunnel is selected for analyzing the changing law of the supplementary air volume at both ends of tunnel by a multi-scale coupling method. The partial transverse ventilation system has been installed in this tunnel. For a long tunnel, one-dimensional (ID) model or three-dimensional (3D) model has its own limitation in the numerical simulation. A multi-scale model which couples ID and 3D models has been adopted. The computed results by multi-scale couple model are compared with those by 3D model in which open boundary condition are set at two portals. The results indicated that the air supplement volume at two portals of the tunnel by multi-scale coupling method is less than the recommended value of smoke exhaust by engineering standard. In addition, the multi-scale coupling simulation has obvious advantages in evaluating the functional of partial transverse ventilation systems. A formula has been put forward for the design of smoke exhaust volume. Compared with the recommended value of the smoke production in the engineering specification, this smoke calculation formula is more operable and more convenient to estimate the capacity of the exhaust system in design.