Mathematical Models for Calculating Heat Release Rate in the Room Corner Test

Abstract

An extensive research program, dealing with fire growth on combustible wall lining materials, has been ongoing in Sweden over the last decade. Several lining materials were tested in bench-scale fire tests in order to derive basic material flammability parameters. The same materials were also tested in a full scale room test and a ⅓ scale room test for two different scenarios, A and B. Scenario A refers to the case where walls and ceiling are covered by the lining material, Scenario B where lining materials are mounted on walls only. This study utilizes the results from these experiments and presents mathematical models where material properties derived from standardized bench-scale tests are used as input data. The models predict fire growth in the full or ⅓ scale tests, and consist of submodels for calculating the rate of heat release, gas temperatures, radiation to walls, wall surface temperatures, and flame spread on the wall lining material. A thermal theory of wind-aided flame spread on thick solids is examined and solutions are given and analyzed for flame spread velocities under ceilings. The results from the models are compared with experiments on 22 materials tested in the full scale room for Scenario A. Comparisons for Scenario B are made with 10 materials tested in the ⅓ scale room. The results show reasonably good agreement for most materials between the model and the experiments.