En förstudie till Tisova brandförsök i FDS
Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
Most current models used for structural fire design are based on traditional methods. These methods usually assume a standard room fire restricted to uniform burning in the compartment. Studies made of fires in large compartments show that the fire tends to travel across the floor area as it ignites fuel in its path. This phenomenon is called a travelling fire.In the beginning of 2015 a test of a travelling fire is planned to take place in Karlovy Vary in the Czech Republic. The fuel in this test will consist of wood. The purpose of the project is to let several parties investigate the structural response at elevated temperatures using different methods and models.The aim of this thesis is to make a priori investigation of what levels of adiabatic surface temperatures (AST) and gas temperatures to be expected at different fire load densities in the full-scale test in Karlovy Vary. This will provide guidelines of the amount of fuel to be used in the test and also be the basis of further studies in which the structural performance will be researched. The objective is to create a model of the building in Karlovy Vary and simulate a travelling fire between wood cribs using Fire Dynamics Simulator (FDS) version 6.0.0 and 6.0.1.Four different models have been made based on three different fire load densities. In two of the models the same fire load was used but the AST was measured differently. The fire load densities in the models were 338, 563 and 844 MJ/m2.The results show that existing traditional models are not suitable to represent a travelling fire. It is found from the models that the difference in gas temperature will be significant depending on where the temperature is measured and at what time the measurement is performed. The fire load density is also a governing factor where a greater fire load will result in higher temperatures.It was concluded in the study that it is possible to model a travelling fire with wood cribs using FDS. However a complex pyrolysis model is extremely time consuming to model in FDS, but if the Heat Release Rate (HRR) for one wood crib is known it is possible to shorten the computational time. Hence it is important to verify the HRR for one wood crib and the fire spread between the cribs.According to the simulations the expected gas temperature in the near field of the fire will vary between 600 – 1100 °C in the full-scale test. The AST at the ceiling is expected to vary between 700 – 1100 °C depending on the fire load density.
Place, publisher, year, edition, pages
2015. , 62 p.
Teknik, Travelling fire, träribbstaplar, FDS, Tisova brandförsök, brandbelastning, brandförlopp
IdentifiersURN: urn:nbn:se:ltu:diva-52167Local ID: 94ec7812-c88a-47a1-8f7c-2f55851413c5OAI: oai:DiVA.org:ltu-52167DiVA: diva2:1025534
Subject / course
Student thesis, at least 15 credits
Fire Protection Engineer, bachelor's level
Validerat; 20150409 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved