Jämförelse av FDS-simuleringar

The aim of this report is to investigate how and if FDS simulations performed by experienced fire protection consultants varies in result, and how different Swedish fire protection companies works with quality assurance of calculations carried out by FDS. This was examined by allowing eight fire protection consultants from different companies simulate a specific scenario with FDS 5, without prior access to the results of an experiment performed under identical conditions. The simulation task was designed so that the participants received relatively well-defined information about the building, fire, initial conditions and the measurements that were to be performed. In addition, the eight participants and an additional three fire protection consultants from other companies were asked to answer a questionnaire regarding how their company deals with quality assurance of FDS simulations. The results of the study indicated variation among the participants in all requested parameters, and the largest were that of mass loss rate and heat release rate which also led to differences in temperature. The methodology and choice of input data also differed to some extent between the participants. The questionnaire results found that quality assurance of FDS simulations does occur in Swedish consulting companies, but to what extent often varies depending on purpose and complexity

Variation in Results Due to User Effects in a Simulation with FDS

The results from a round-robin study in which practicing fire safety engineers simulated the same scenario are presented in this paper. The simulation task included the simulation of an 800 mm heptane pool in a three-room apartment. The participants, representing eight Swedish consultancy firms, simulated the well-specified scenario with FDS 5. The participants received information about the building, the fire mass loss rate and initial conditions. The task was performed a priori, meaning that the participants were not given any experimental or simulation results prior to performing the task. The study shows that there is a variation between the participants in how the input file was specified, the choice of input data and the types of devices used in FDS. The differences in how the fuel and the burner were described were relatively large, which resulted in large differences in mass loss rate and heat release rate. Furthermore, several of the participants made mistakes when the fire was prescribed and this resulted in a variation in the calculated parameters like the temperature increase, which was 300 K in the fire room and 50 K to 150 K in the adjacent rooms. However, the study shows that when the heat release rate and wall boundary conditions were well defined, good temperature predictions could be made