Selection And Its Criteria Of Computational Domain On Numerical Simulation Of Building Fires

Because of the innovation of the architectural form with the technologies progress, fire prevention and extinguishment tend to be difficult and complex. Therefore, the fire research and fire protection design are particularly important. In order to solve the contradiction between experiment and application requirements, computer numerical simulation technology was born. After decades of development and optimization, it becomes the one of the important tools of scientific research and engineering application.In the process of numerical simulation of building fires, the reasonable selection of computational domain (the reasonable setting of model boundary) is directly related to the accuracy of simulation results. Therefore, the issue of the selection of computational domain is catching more and more attention of scholars, domestic and overseas. However, due to the difficulty of quantitative analysis, the lack of quantitative analysis method, the complexity of fire factors and other research puzzles, most of the existing related research is rare or limited in qualitative analysis level.Based on the predecessors’works, this text would be focused on the selection of computational domain during the transitional region, which is a transformation of the Fuel Controlled Fires into the Ventilation Controlled Fires, with FDS. This article tried to introduce a new correlation analysis method. And according to this method, the quantitative selection gist of computational domains was summarized and verified preliminarily. Then, the effects of computational domain on simulation results under different room-aspect-ratio were quantitatively analyzed by this selection gist. Above all were dedicated to provide the data reference and theoretical support to the further research of fire transitional region. The main content concluded:1. The first part analyzed the effects of computational domain extension on simulation results, under the conditions of different heat release rate during the transitional region. And a new correlation analysis method, as a quantitative selection method, would be introduced. According to this method, the relative error value and the absolute value of its derivative would be calculated. Then the corresponding line chart would be draw. And the results show that all the values appearance apparent fluctuation and tend to converge. Thus, the convergence criteria had been established with above data and charts. And these criteria could be regarded as the selection gist of computational domain. Furthermore, these criteria had been verified preliminary.2. Based on above correlation analysis method, correlation analysis method and velocity (vector) profile of the room specific plane. The effects of computational domain on simulation results under different room sizes (room aspect ratios), during the transitional region, had been analyzed. Then, through the dimensionless analysis, the selection gist of computational domain extension under different room sizes (room aspect ratios), during the transitional region, had been established.