Numerical simulation on the maximum temperature and smoke back-layering length in a tilted tunnel under natural ventilation

Abstract The present study investigates the maximum temperature and smoke back-layering length S in downhill direction from fire source a tilted tunnel under natural ventilation. Numerical simulations were conducted using FDS to flow behaviors for with nine slopes of 0, 1%, 2%, 3%, 4%, 5%, 6%, 7% 8%. It was found that, due stack effect, stagnated at distance direction. effects slope, ? , heat release rate, Q source-ceiling height H width W on studied. Results showed that ceiling decreased increasing slope or decreasing width. However, it increased rate height. A model proposed rise. slope. Fire had no significant effect length. And Based dimensional analysis, simple including both H, predict