Effect of train fire location on maximum smoke temperature beneath the subway tunnel ceiling

Smoke temperature beneath tunnel ceiling is one of the most important parameters to determine its fire safety. A double long-narrow space is formed when a subway train stops inside a tunnel, where the smoke movement is quite different from those inside traditional road or train tunnel. The related smoke distributions beneath the tunnel ceiling in this double long-narrow space have been rarely investigated previously. Therefore, through this study, the effect of train fire location on the maximum smoke temperature beneath the subway tunnel ceiling were investigated both numerically and theoretically. Results showed that the smoke temperature beneath the tunnel ceiling is closely related to the spill plume through the train door, which is significantly affected by the fire location. The maximum smoke temperature beneath the tunnel ceiling increases exponentially as the fire source moves away from the train center. A modified model was then developed to predict the maximum temperatures under the spill plume considering various heat release rates and fire locations.