Sprint – A Design Tool for Fire Ventilation

A new one-dimensional time-dependent computer model for analysing fire scenarios in tun-nels is presented. The new model is able to handle arbitrary ventilation systems. An important feature is its ability to handle gravity-driven smoke propagation arising from thermal stratifi-cation. The new model was implemented in the computer code ‘Sprint’. The validation was based on results from full-size fire tests and from additional flow measurements. ‘Sprint ’ was able to reproduce in a qualitatively and quantitatively correct way the main experimental findings. It was concluded that the model is suitable for design and design review work. The application to existing tunnels, e.g. Gotschna and la Vue-des-Alpes, illustrates the ability of the code to handle real-life situations. Using the 1-D code, the short calculation time allows for the simulation of many different scenarios (parametric studies) in a reasonable time. ‘Sprint ’ has been used not only for safety studies, but also for the design of optimised control routines for fire ventilation. NOMENCLATURE A [m2] area Dh [m] hydraulic diameter g [m/s2] gravity constant k [-] factor p [Pa] pressure Q [W] heat flux T [K] temperature t [s] time u [m/s] velocity x [m] axial distance a [W/m2K] heat transfer coefficient e [-] emissivity l [-] wall friction coefficient r [kg/m3] density of air s [W/m2K4] Stefan-Boltzmann con-stant Indices sm smoke tun tunnel V ventilation wall wall 0 initial conditio