Abstract: To study the lateral smoke exhaust performance with the air baffle, the characteristics of temperature field and flow velocity vector field near the lateral exhaust vent, as well as the smoke exhaust efficiency, were explored under the air baffle with different tilt angles. The results show that the air baffle below the lateral exhaust vent can effectively inhibit the inflow of cold air and improve the performance of lateral smoke extraction. After the air baffle is set below the sidewall vent, the streamline of the hot smoke near the vent increases significantly, and the cold air streamline becomes sparse, and the high-temperature smoke area in the lateral vent increases with the tilt angle of the baffle. When the exhaust vent aspect ratio is 1：2, the lateral smoke exhaust efficiency is increased with the larger title angle of air baffle within 0≤θ≤45°, and then remains basically unchanged with the larger title angle of air baffle, achieving the best lateral smoke exhaust performance within 45°≤θ≤60°. When the vent aspect ratio is 2：1, the lateral smoke exhaust efficiency is increased with the larger title angle of air baffle within 0≤θ≤30°, and it shows decrease trend with the larger title angle of air baffle within 30°≤θ≤60°, achieving the best smoke exhaust performance at 30°. Finally, a prediction model of lateral exhaust efficiency under air baffles with different tilting angles is obtained through data fitting, which can provide a corresponding technical guidance for the design of tunnel lateral smoke exhaust system.

Key words: lateral smoke extraction, plug-holing phenomenon, smoke exhaust efficiency, air baffle, tilt angle