Development of Multi-layer Zone Smoke Transport Computer Model

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Traditionally, fire safety designs of buildings have been guided by prescriptive provisions set out in building and fire service laws. Recent years, however, demands for more rational and cost-effective designs have become stronger reflecting the notable progress in fire safety engineering and worldwide trend of performance-based fire safety design practices have developed. It is noted that fire models such as 'two layer zone models' and 'CFD models' have played a great role in the new fire design practices. The former, which predicts fire physic behavior of smoke transport by considering an upper and lower layers in each room of a building as control volumes, have been most popular in fire safety design practices because of its undemanding computational burden although it can only predict average physical properties of the two layers. On the other hand, the latter have been more powerful to investigate fire behavior in detail because it can give a great amount of information on fire p … More henomena although its computation is significantly demanding.In this project, a new smoke transport model was developed based on multiple layer concept. It can give more detailed information than two layer zone models such as vertical distributions of temperature and species concentrations in rooms and ceiling jet temperature while maintaining the undemanding nature of two layer zone models in computational time and data input. In this model, each room in a building is divided into arbitrary number of horizontal layers. The physics relating smoke transport were mathematically modeled letting each horizontal layer as a control volume to establish a formula set of the model and a computer model was developed for numerical computation of the model. Incidentally, the fire plume in this model continues to rise until hitting room ceiling unlike the uniform mixing in the upper layer of a fire plume assumed in the existing two layer zone models. The predictions by the multi-layer zone model were compared with the results of a full-scale fire test conducted in this project and some of the existing experiments with satisfactory agreement. This model is evaluated to be a potential candidate of new generation smoke transport to be used in fire safety designs of actual buildings. Less