# Computational Fluid Dynamics of Compartent Fires: A Review of Methods and Applications
## 1 Introduction
According to ASTM E 1355 (Standard Guide for Evaluating the Predictive Capability of Deterministic Fire Models) [15] and as cited by [16], fire simulation and modeling can be divided into three categories: blind (priori), specified, and open (posteriori). The difference between these methods is the approach the user takes, the purpose of simulation, and finally, the available data and information, i.e., the required input for the CFD tool. In  
Figure 1: Schematic diagram of heat release rate in different stages. Adopted from [PERSON] and [PERSON] [11]. terms of terminology, blind simulation can be applied to the situation when the user has only limited knowledge of the fire scenario, without any details about geometry, material properties, fire growth, etc. In case of blind simulation, all inputs must be prepared by the user based on the personal impression, and as a result, this scenario can only represent a forecast from the fire behavior. Specified simulation has a different trait, where all required inputs and more details are provided to the user. The most detailed and complete group of simulations is called open. In addition to specified simulation indices, experimental measurements criterion from the first two categories are available in open simulation. In the specified or open simulation, the inputs to be used in the CFD tool are provided for the user. But how does it work in case of fire simulation? For instance, using measured data in the experiment as the input for the simulation: the mass loss rate (MLR) or heat release rate (HRR) is defined on an obstruction or vent that defines the fire, representing a burner with a controlled amount of fuel [12]. On the other hand, when the fire description is not available, required inputs of the CFD simulation tools (e.g., thermochemical properties of the fuel, thermomechanical properties of the surfaces, etc.) are chosen based on references such as handbooks and standards; blind simulation is conducted. There are some cases in which the modeling is not fully specified/open or blind and is the combination of both modes, i.e., is defined as semi-blind. In other words, when some parameters like geometry details and material properties are specified and known, while other experimental measurements such as MLR or HRR are not. This can result in an output which is not in good agreement with real conditions [17]. In such cases, the predictive ability of the tools comes in handy to predict the HRR (or MLR) using the fuel properties. In such simulations, heat feedback from the flame to the fuel surface determines the burning rate of the fuel [12; 18]. According to [PERSON] and [PERSON] [19], when there is no available experimental data for HRR or MLR, the thermal and kinetic properties of the fuel should be specified in the case of simulating free-burning in FDS. While using CFD tools and methods for simulating fire dynamics such as in a compartment fire, the credibility and reliability of the configured models must be assessed, and it should be determined whether the simulation outputs are authentic. This issue can identify the possible discrepancies between the CFD model and the corresponding real-world scenario and is defined as model validation which will be discussed in following section.