No abstract

The very first tunnel was developed about 4000 years ago and since then the art of tunnelling has evolved to a great extent. With advancement in the field of science and technology tunnels have grown from a mere defence strategy to something that can carve its way to places that were once unapproachable. However, there are various problems associated with tunnels that are yet to be addressed, fires being one of the major ones. Astonishingly, 70% of deaths during a fire are caused by smoke inhalation and only 30% of deaths are the result of the fire. Every year an enormous amount of money, effort and time is put into research to prevent such fires and minimize the damage it causes and yet no significant result has been obtained till now. This is primarily because of the diversified nature of fires which results in heterogeneous heat and mass transfer. A jet fan is mechanism that can extract smoke quickly, safely, and efficiently. The present work focuses on testing the effectiveness of Jet fans to suppress these fires and minimize the accumulation of smoke, thereby bringing down the number of deaths to a significant amount. In this paper, a numerical study is carried out using FDS SMV. Multiple parameters such as HRRPUA, volume flow rate, etc. are varied and the corresponding change in the temperature, velocity, the heat generated, etc. is observed. The key controlling parameters are taken and varied proportionally to see how each one affects the performance of the jet fans. Consequently, a conceptual design has been proposed specifically for tunnel fires. This study aims to understand the potency of jet fans with changes in various parameters and to utilize them effectively to suppress not just tunnel fires but also building fires, fires in aviation etc.