Emergency smoke ventilation for a uni-directional traffic road tunnel is studied using a CFD modelling approach. Fire scenarios in an uphill ramp for congested traffic conditions have been considered. Based on a longitudinal smoke ventilation system with a damper smoke-extraction device on the ceiling soffit, the impact of longitudinal ventilation (LV) control, operation of fire suppression int...

During the actual operation of a subway company, only one ventilation-control scheme is considered in emergency plan, without considering specific location difference fire source. However, case an tunnel fire, best and personnel-evacuation are very different given potential locations We consider use connecting channel for smoke exhaust or personnel evacuation study scheme, when source at positi...

With a length of more than 55 km, the Brenner Base Tunnel (BBT) connecting Austria and Italy will be one of the world’s very long tunnels in the future. During the construction phase, climatic conditions need to be maintained fulfilling the occupational health requirements, assuring the functionality of the machinery and allowing the intended construction processes. In view of the extended cons...

A large eddy simulation (LES) program with the Smagorinsky subgrid-scale model has been used to study cross natural ventilation in buildings, which has experimental data available from on-site measurements and a wind tunnel. Since natural wind changes direction over time, it is hard to reproduce this effect in a conventional wind tunnel where the “wind” direction is fixed. There are discrepanci...

In ventilated tunnel fires, smoke and hot combustion products may form a layer near the ceiling and flow in the direction opposite to the ventilation stream. The existence of this reverse stratified flow has an important bearing on fire fighting and evacuation of underground mine roadways, tunnels and building corridors. In the present study, conducted by the National Institute for Occupational...

Three trials, using a total of 1,320 male broilers, were conducted to study the effect of air velocity at 125 m/min on body weight gain and feed: gain. The broilers were placed on litter in pens in a wind tunnel or on litter in floor pens with conventional cross ventilation when 4 wk old. Except for air velocity, the conditions in the floor pens and the tunnel were the same. In Trials 1 and 2, ...

Nest ventilation in the leaf-cutting ant Atta vollenweideri is driven via a wind-induced mechanism. On their nests, workers construct small turrets that are expected to facilitate nest ventilation. We hypothesized that the construction and structural features of the turrets would depend on the colony's current demands for ventilation and thus might be influenced by the prevailing environmental ...