Numerical and experimental study on smoke diffusion characteristics of tunnel with ceiling beams.

Ceiling beams at the top of tunnels are more common in actual projects. Under the influence of thermal buoyancy, the ceiling structure significantly affects the diffusion characteristics of fire smoke within the tunnel. This study performed several sets of model experiments and numerical simulations to investigate the impact of the height and spacing of ceiling beams on the diffusion of smoke in tunnel fires, which results show that the maximum temperature rise and temperature decay patterns of fire smoke follow exponential changes.