Study on the Influence of the Curvature Radius of the Branch on Fire Temperature Characteristics in Bifurcated Curve Tunnel

In order to explore the influence of the radius of curvature (ROC) of the branch on the ceiling temperature in the bifurcated curve tunnel, the numerical simulation method is used in this paper to study the fire scene where the fire source is located at the bifurcated point under the longitudinal ventilation condition. The results show that the ceiling maximum temperature rise of the bifurcated curve tunnel increases with the heat release rate of the fire source, and decreases with the increase of the longitudinal ventilation velocity or the ROC of the branch. Based on the data analysis, a prediction model for the ceiling maximum temperature rise of the bifurcated curve tunnel is proposed in this paper, which considers the influence of the ROC of the branch. For the ceiling longitudinal temperature distribution of the branch, when the ROC of the branch is small, the ceiling longitudinal temperature will briefly increase at the entrance of the branch. In the downstream area of the branch, the ceiling longitudinal temperature increases with the ROC of the branch.