Estimating the two-dimensional thermal environment generated by strong fire plumes in an urban utility tunnel

Two-Dimensional Analysis on Ceiling Jet Temperature Characteristics in a Semicircular Tunnel

“…It is the significant parameter when determining the vertical temperature profile. According to the former literature [42,55], characteristic thermal thicknesses beneath ceiling have the same trend with increasing of x. As a result, it could be inferred that Gaussian thermal thickness LT in this work could be described by function of x/H and LT/H, which is similar with the form of Eq.13.…”

“…7, the boundary between Region II and III is defined as x/H=9. Even though the boundary was determined by experimental data, it could still find reference from work proposed by Ye et al [13,42]. In their work, the ceiling jet was produced by evolution of δ(x)/H performing two distinct stages and the boundary is around x/H≈10, which is similar with that in this work.…”

“…According to the former literature [42], interfaces where T/Tmax=1, 0.8, 0.5 and 0.2 perform a great consistency and the distance between these interfaces remains stable regardless of position.…”

“…Ye's model (green line) obtained from these data points could not perform well in this region. On the other hand, because of the thermocouple arrangement [13,42], maximum temperature measured may not the actual value, which means the boundary position determined by raw temperature data may have the deficiencies in accuracy.…”

Dynamic resilience assessment and emergency strategy optimization of natural gas compartments in utility tunnels

“…However, the relevant accidents, operation data, or management experience are too scarce to support the risk assessment and safety management of utility tunnels since the boom of large-scale multicompartment underground utility tunnels just emerged in the last decade. Recently, for the safety analysis of gas pipelines inside utility tunnels, there have been hazard identification techniques (Bai et al, 2020), index-based approaches (Canto-Perello et al, 2013), probabilistic models (Fang et al, 2019;Wu et al, 2021), experiments (Ye et al, 2021;Zhao et al, 2022) and numerical simulations (Cai et al, 2022;Wu et al, 2020) conducted. The index-based approaches like the analytic hierarchy process (AHP) are easy to integrate with other tools and practical for application in reality.…”