Utvärdering av tunnelbrandsmodeller

Sammanfattning: The purpose of this study was to investigate the predictive capabilities of hand-calculation methods and simulations using FDS in understanding the behavior of a tunnel fire in terms of temperature and incident radiation. Additionally, the study aimed to examine the repeatability of a large-scale fire experiment. The research commenced with the execution of three similar experiments, further called test 1, 2 and 3, in a tunnel facility constructed for fire experiments. A heptane pool was used as fire source and ensuring uniform conditions for each experiment. Subsequently, the same fire scenarios were simulated using FDS, and hand-calculations. The results indicated that repeatability was generally favorable for experimental tests 2 and 3, while test 1 exhibited distinctive different characteristics. One plausible explanation for this discrepancy could be that the first test desiccated the materials in the tunnel, given its prior unused state. Furthermore, only output data from tests 2 and 3 were utilized. Hand-calculations, as a method, has proven to be time-efficient and suitable for quickly estimating tunnel temperatures. However, for more precise results where numerous parameters can be tailored to each individual experiment, hand-calculations may fall short. In summary, FDS emerges as a robust method for predicting temperatures in tunnel fires, and the results accurately reflect the input conditions. The efficacy of the FDS method is dependent on the knowledge possessed by the engineer conducting the simulation regarding fire development, influential parameters, and the complexities of the program. The more comprehensive the understanding of these elements, the more accurate the results obtained.