Simulation of Thermal Exposure and Response of Structure in Fire
In this simulation, Simtec is used to compute thermal exposure and the conjugate heat transfer of steel structure in oil pool fire. The simulation results are validated against experimental measurement with good agreement.
In the simulation, no heat release is prescribed. Instead, the fuel supply into gas phase combustion is fully based on the automatically calculated fuel evaporation rate, which is governed by the gas convection, thermal radiation and heat transfer inside the pool, etc. The computed fuel evaporation rate agrees well with experimental measurement.
When the steel column is heated by the fire and hot gas around at the outer surface, heat will be transferred inside the steel column by conduction. Thus, the inner surface of the steel column will also become hot. This will then invoke thermal radiation heat transfer and gas convection in the column interior empty space. This invoked heat transfer, particularly the thermal radiation can have significant influence on temperature distribution in the steel column. In the simulation, all these processes are considered and computed.
The simulation domain is 7mx10mx7m and the smallest gas phase cell size is 1.23 cm. Separate solid phase meshes are used to compute the conjugate 3D heat transfer inside all the solid materials which can have temperature dependent thermal properties. The smallest solid phase mesh size is 0.5 mm.
Figure 1 Comparison of computed steel column temperature with measurement at column height of 1.0 meter
Figure 2 Comparison of computed steel column temperature with measurement at column height of 2.0 meter
Figure 3 Temperature profile animation
This animation also shows that the inner space air inside the enclosed steel column is quite much heated up by the steel structure, even though the smoke can not enter into the inner space.