In the corridors, combustion products of the fire are confined to spread in one or two directions, forming a ceiling-jet flow. For safety assessment and emergency treatment, it is important to investigate and understand the behavior of the ceiling-jet flow. In this paper, a simplified model has been developed and improved, which has been verified by the numerical calculation. It is worth mentioning that for the radial spreading region, we have simplified Alpert's equations, and obtained the simplified solution. Moreover, in this region, the mass entrainment has been got by linear fitting. And for the region of hydraulic jump, two sub regions of IV1 and IV2 have been established to analyze the conversion process. In order to validate the theoretical predictions, a series of small-scale experiments and numerical simulations have been conducted to validate the physical model of corridor fires. The predicted results, concerning exit position and flow state in near field, agree favorably with experimental data in different conditions. (C) 2015 Elsevier Ltd. All rights reserved.