A Comparison of CFAST Predictions to USCG Real-Scale Fire Tests

Abstract

The zone model CFAST was used to make predictions of single room preflashover fire tests conducted in a steel enclosure. These results were then compared with previously published measurements obtained in fire tests. Tests included diesel pool fires, polyurethane slab fires, and wood crib fires. Half of these tests used natural ventilation (window, 1/4 door, and full door) while the remaining tests used forced ventilation (0.25 m3/s, 0.38 m3/s, and 0.61 m3/s). With the exception of heat release rates, all CFAST inputs were selected without knowledge of the experimental results. Key variables compared include the upper layer temperature, the hot layer interface location, and ceiling temperatures. Overall, predictions made by CFAST were in good agreement with the data. There was a general tendency to over predict both the hot gas layer temperature and the boundary surface temperature which may be due to under prediction of boundary heat losses. Experimental results showed that heat release rates varied with ventilation configurations by as much as a factor of 3. This observation indicates that thewide practice of using free burn heat release rate data in compartment fire predictions can result in over prediction of compartment fire conditions.

Application of symbolic mathematics in modelling fire for providing a safe environment

“…Z i are also compared with CFAST 4.01 (e.g. [27]) predictions and the following smoke filling equations:…”

Numerical experiments and compartment fires

“…The graphical comparisons can also be complemented with a quantitative number of the difference between the two sets of data. This was, for example, done in a comparison of CFAST predictions to real-scale compartment fire tests with natural and forced ventilation (Reneke and Peatross 2001) and it was found that the CFAST model over-predicted upper layer temperatures with less than 50°C. Another example is the modelling of the Dalmarnock fire tests (Rein et al 2011) where a posteriori simulations over-predicted the hot layer temperature by 10-50%.…”

Evaluation of the Prediction Performance of FDS Combustion Models for the CO Concentration of Gas Fires in a Compartment

“…Measuring positions of thermocouples trees (TF and TR) and concentration probes (CF and CR) and compartment size of experimental data. (3) 가 가장 대표적인 Filed 모델 코드로서 활용되고 있 으며, CFAST (4) 와 같은 Zone 모델 코드도 많이 활용되고 있 다. 최근에는 FDS와 같이 소스가 공개된 FireFOAM 코드 (5) 를 이용한 화재해석도 점차 증가하고 있다.…”