Several commonly used fan sizes and blockage distances are investigated in this study.
Varied longitudinal ventilation velocities, fire heat release rates, and blockage-fire distances D were considered.
Still to be debated: the distance that blockage can be remediated — 100 feet, 1,000 feet or unlimited.
In order to study the effect of varied blockage-fire source distances (rectangular cylinder shape) on the smoke layer thickness in a longitudinal ventilated tunnel, a series of experiments were conducted in a 1/6 model tunnel platform.
The rays with activity percentage about 40 70 % are the R-rays: the reflections from far-away static objects, weaker, and more susceptible to blockage due to longer travel distance.
Should the distance of the blockage be limited to 300 feet, 500 feet or as far as the eye can see?
Combinations of three different blockage ratios and three different separation distances (defined as the distance between the perforated plates and target plates) were used during the blast experiments to ascertain the influence of the two variables, while the charge to target plate stand-off distance was kept constant.
By means of applying self-designed experimental system for flame acceleration, the paper investigated solid structure, blockage ratios, spatial layout and ignition distance of obstacles influence on flame speed and overpressure.
In this work a vented cylindrical vessel 162 mm in diameter 4.5 m long was used to study the effect of separation distance of two low blockage (30%) obstacles.
Thus, fixed PP and CR are 2 s and 2/3, respectively, because the mean open distance, velocity, and the blockage fraction are 30 m, 60 km/h, and 33%%, respectively [2].
