• Background context of the research topic
The computational fluid dynamics (CFD) modelling approach gained impetus in the fire science and technology during the last decades because it is efficient and economical compared to the traditional experimental approach. Moreover, detailed information about the flow field and temperature distribution that are important to the fire spread mechanism becomes accessible by the CFD approach.
Several CFD software packages have been developed in the past years, some of them are specially designed for fire modelling. However, CFD modelling of the fire test case involves several areas such as fluid dynamics, turbulence, heat and mass transfer, combustion, chemistry, mechanical systems, and structural properties of the enclosure.
At present, it is not possible to account for all the details of a fire in the CFD modelling because a typical fire is extremely complicated. How to simplify the complicated physics of a fire, so that the major features of the fire are captured, is still an important issue of modern CFD modelling.

• Review of existing research literature
There have been many studies on the numerical simulation of fire, and much progress has been made recently. Prediction of the course of fire can be obtained by experimental investigations and mathematical modelling, a full scale experiment is ideal to give the most reliable information about a fire process. However it is expensive in terms of both resources and time. Sometimes it is even impossible to do so, because of high costs, difficulties in actual measurements and hazards that may be involved. The usual alternative is to perform experiments on reduced scale and then the resulting information must be extrapolated to full scale and general rules for doing this are often unavailable. Furthermore, the reduced scale experiment does not always have all the features of a full scale experiment. This further reduces the usefulness of the experimental investigations. It should be kept in mind that, even where full scale experiments are achievable, the results are not necessary entirely accurate. The measurement process is seldom free from errors.
Over the last two decades there has been a significant increase in our understanding of fire development and its influence on its surroundings. Understanding of fire changed from being empirical to being scientifically based. This change and more widespread access to powerful computers at low cost has resulted in ever more fire scene reconstruction solutions that have been found through the use of mathematical models. The development of numerical methods further increases the possibility of using mathematical models, in Partial Differential Equation (PDE) form, which describe the physical and chemical processes predict many fire phenomena of practical interest.
Fire scene reconstructions require the CFD model to simulate an actual fire based on information that is collected after the event, such as eye witness accounts, unburned materials, burn signatures, etc. The purpose of the simulation is to connect a sequence of discrete observations with a continuous description of the fire dynamics. Usually, reconstructions involve more gas/solid phase interaction because virtually all objects in a given room are potentially ignitable, especially when flashover occurs. Thus, there is much more emphasis on such phenomena as heat transfer to surfaces, pyrolysis, flame spread, and suppression. In general, forensic reconstructions are more challenging simulations to perform because they require more detailed information about the room contents, and there is much greater uncertainty in total heat release rate as the fire spreads from object to object.

• Research questions
As a researcher I recognize that there are many scientific deficiencies in the current CFD modelling of the fire. These deficiencies are not such as to require abandonment of the whole approach, research is needed to overcome these deficiencies by improving the relevant models for turbulent transport, radiation transfer, etc.
In this investigation, a self-developed numerical model which will be customized for studying the behaviour of fire will be developed and validated with full-scaled experimental data. The numerical model will attempt to completely simulate the simultaneously occurring flow, temperature distribution, turbulent, combustion, soot chemistry and radiation effect in fire scene reconstruction.
Results of this investigation will be to characterise the capabilities and limitations of computational fluid dynamics to predict the smoke movement and fire behaviour in enclosure fires.