For a reheating furnace, an analysis of thermal efficiency depends on precise investigations of the combustion and flow characteristics inside a furnace. Especially, the flow field of the hot gas has significant influence on heating slabs. The slabs are heated up to the temperature over 1500 K, and then they are transported to the rolling mill. The heating efficiency is affected by many factors, such as fuel type, locations of both slabs and burners, thermal properties of slabs, geometry of slab supporting systems, and so on. In the paper, some efforts were made to simulate the thermo-fluid mechanical phenomenon inside the furnace. The slab heating characteristics in the reheating furnace were investigated by using the finite-volume method (FVM). The unsteady calculation was performed to obtain the temperature distribution by considering the movement of the slabs in the reheating furnace. To treat radiation emitted by the walls and the gas, numerical simulations were completed by employing ANSYS FLUENT. The configurations of skid posts and beams were also considered to evaluate the effect of the burner position. Results indicate that the case with 6 side burners has a higher heating efficiency both in the heating and soaking sections. (C) 2017 Elsevier Ltd. All rights reserved.