Shengzhong Zhao¹, Daiyan Chen¹, Han Zhang^1,2,*, Junhao Yu¹, Lin Xu¹, Zhaoyi Zhuang¹, Fei Wang^1,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1907-1932, 2025, DOI:10.32604/fhmt.2025.071910 - 31 December 2025

Abstract A sealed portal could significantly alter the flame shape and smoke flow characteristics in inclined tunnel fires. In inclined tunnels, two typical sealing conditions could be defined, namely the upper portal sealed and the lower portal sealed. In this study, the effects of tunnel slope on flame shape, flame length, along with smoke mass flow rate and induced velocity at the tunnel portal, are numerically investigated. The results show that, in all scenarios, flames initially rise vertically but tilt toward the sealed portal during the quasi-steady stage, with the largest tilt angle observed in tunnels… More >

Ciro Caliendo, Isidoro Russo^*, Gianluca Genovese

CMES-Computer Modeling in Engineering & Sciences, Vol.144, No.1, pp. 693-715, 2025, DOI:10.32604/cmes.2025.068123 - 31 July 2025

Abstract Road pavements in tunnels are usually made of asphalt mixtures, which, unfortunately, are flammable materials. Hence, this type of pavement could release heat, and more specifically smoke, in the event of a tunnel fire, thereby worsening the environmental conditions for human health. Extensive research has been conducted in recent years to enhance the fire reaction of traditional asphalt mixtures for the road pavements used in tunnels. The addition of the Flame Retardants (FRs) in conventional asphalt mixtures appears to be promising. Nevertheless, the potential effects of the FRs in terms of the reduction in consequences… More > Graphic Abstract

Zhisheng Xu¹, Juan Wang¹, Zihan Yu¹, Jiaming Zhao^2,*

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1129-1151, 2024, DOI:10.32604/fhmt.2024.053695 - 30 August 2024

Abstract Called island-crossing tunnels, some specific underwater tunneling projects face constraints imposed by geological and water conditions, necessitating their passage through artificial or natural islands. The longitudinal of the tunnel follows a W-shaped distribution. The congestion situation does not allow for immediate longitudinal smoke exhaust at the early stage of the fire, and the natural spread of smoke is complicated. An exhaustive investigation was carried out to analyze the smoke behaviors during a fire incident, employing the fire dynamics software FDS, considering five slopes and four fire locations. The simulation results reveal that the layer of… More >

Liang Yi, Zhiqiang Lei, Zhisheng Xu, Yaolong Yin, Houlin Ying^*

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 977-996, 2024, DOI:10.32604/fhmt.2024.053688 - 30 August 2024

Abstract This paper explores the smoke flow characteristics in tunnel fires, giving a particular emphasis on the effects of different distances between the smoke outlets and the fire source. It examines the smoke behavior under different conditions, including variations in heat release rates, exhaust volumetric flow rates, spacing between smoke outlets, and the longitudinal fire source positions. Results indicate that altering the fire source positions and the smoke outlets in the tunnel leads to variations in the properties of smoke flow both the fire source upstream and downstream; the distance between fire source and smoke outlet… More > Graphic Abstract