A Comparison of a Statistical and Computational Fluid Dynamics Approach to Estimate Heat Release Rate in Road Tunnel Fires

Abstract

Computational tools such as one-dimensional models or Computational Fluid Dynamics (CFD) have been used for the fire safety design of road tunnels. However, most of these analyses are performed using a specified fire source where the heat release rate (HRR) in the tunnel is fixed by the user and the influences of ventilation conditions and tunnel geometry are not considered. For a more realistic estimate, models need to incorporate these factors in their input. This paper discusses the use of a statistical approach previously developed by other researchers (Carvel and Beard, The handbook of tunnel fire safety. Thomas Telford Publishing, pp [184][185][186][187][188][189][190][191][192][193][194][195][196][197] 2005) and the use of a CFD approach to estimate the HRR in a road tunnel fire. As an application example, fire scenarios in which a light goods vehicle carrying wooden pallets are used to compare the estimation of the HRR using these two methods.

Tunnel Fire Dynamics as a Function of Longitudinal Ventilation Air Oxygen Content

“…Several studies [18][19][20][21][22][23][24][25][26] explore this further. One study [35] employs the computational fluid dynamics approach to estimate the heat release rate in a road tunnel fire, while other studies [18][19][20][21] use a statistical approach to quantify the influence of ventilation conditions and tunnel geometry on heat release rate.…”

“…Several studies [18][19][20][21] included experiments to investigate the impact of ventilation velocity on the fire growth rate and the maximum ceiling temperature. While in another study [35], researchers performed numerical simulations to quantify the influence of ventilation velocity on the tunnel fire dynamics. They also compared a statistical and computational fluid dynamics approach to estimate heat release rates in road tunnel fires.…”

A model for the devolatilisation of large thermoplastic particles under co-firing conditions

“…Examples of applied combustion modelling and simulation for PSW particles are scarce, typical examples are presented in [12][13][14][15][16]. On the other hand detailed investigations exist on polymer decomposition regarding intrinsic chemical kinetics, derived from small scale laboratory experiments [17][18][19][20][21], which have been applied to fire situations [22][23][24][25][26][27]. In these latter cases heat and mass transfer phenomena may be the limiting factor, because of the large size of the burning objects [28].…”