Blar i HVL Open på forfatter "Frette, Vidar"
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The average velocity in a queue
Frette, Vidar (Journal article; Peer reviewed, 2009)A number of cars drive along a narrow road that does not allow overtaking. Each driver has a certain maximum speed at which he or she will drive if alone on the road. As a result of slower cars ahead, many cars are forced ... -
Behaviour of smoldering fires during periodic refilling of wood pellets into silos
Fernandez Anez, Maria de Las Nieves; Meyer, Anita Katharina; Elio, Javier; Kleppe, Gisle Yngvar Romslo; Hagen, Bjarne Christian; Frette, Vidar (Peer reviewed; Journal article, 2021)The evolution of smoldering fires in biomass stored in lab-scale silos with additional fuel material supplied repeatedly, has been studied. The direct effects of the added material on the sample are: cooling, enhanced ... -
Early detection of smoldering in silos: Organic material emissions as precursors
Bluvshtein, Nir; Villacorta, Edmundo; Li, Chunlin; Hagen, Bjarne Christian; Frette, Vidar; Rudich, Yinon (Peer reviewed; Journal article, 2020)The possible use of organic particle emissions as indicators of smoldering fires at low temperatures (early stages, <150 °C) is explored in laboratory experiments. Samples consisting of wood pellets were heated under ... -
Extinguishing smoldering fires in wood pellets with water cooling- an experimental study
Mikalsen, Ragni Fjellgaard; Hagen, Bjarne Christian; Steen-Hansen, Anne; Krause, Ulrich; Frette, Vidar (Peer reviewed; Journal article, 2018-11)Smoldering fires in stored or transported solid biofuels are very difficult to extinguish. The current study has explored heat extraction from the combustion zone as a method for extinguishing such flameless fires. Heat ... -
Flame heights and charring on a particle board – An experimental study
Karyaparambil, Dheeraj Dilip; Erland, Sveinung; van Hees, Patrick; Frette, Vidar; Hagen, Bjarne Christian (Peer reviewed; Journal article, 2022)Vertically oriented particle-board samples were exposed to external venting flames to study the fire spread and charring behaviour along a timber façade. Variation in flame height and the height, volume, area, density, and ... -
Lip Height Effects in Quadrangular Steel Containers
Kolstad, Einar Arthur; Frette, Vidar; Hagen, Bjarne Christian (Chapter, 2019)The reduction in the mass-loss rate as a function of lip height is investigated through 90 experiments with hydrocarbon pool fires in quadrangular containers of size 10 cm, 20 cm, and 30 cm. The results show a reduction ... -
Lip-height effect in diffusive pool fires
Kolstad, Einar Arthur; Hagen, Bjarne Christian; Frette, Vidar; Krause, Ulrich (Peer reviewed; Journal article, 2021)A freeboard, lip height, from the container rim to the fuel surface affects the mass-loss rate of a pool fire. Experiments where heptane was burned in circular containers with diameter 10, 20 and 30 cm have been conducted. ... -
Lorentzian-geometry-based analysis of airplane boarding policies highlights “slow passengers first” as better
Erland, Sveinung; Kaupužs, Jevgenijs; Frette, Vidar; Pugatch, Rami; Bachmat, Eitan (Peer reviewed; Journal article, 2019)We study airplane boarding in the limit of a large number of passengers using geometric optics in a Lorentzian metric. The airplane boarding problem is naturally embedded in a (1+1)-dimensional space-time with a flat ... -
Onset of smoldering fires in storage silos: Susceptibility to design, scenario, and material parameters
Villacorta, Edmundo; Haraldseid, Ingunn; Mikalsen, Ragni Fjellgaard; Hagen, Bjarne Christian; Erland, Sveinung; Kleppe, Gisle Yngvar Romslo; Krause, Ulrich; Frette, Vidar (Peer reviewed; Journal article, 2021)Biomass fuels in large storage units are prone to self-heating and ignition causing smoldering fires. Here, the susceptibility of such ignition processes to parameters is explored through small-scale experiments. In a silo ... -
Velocity and cluster distributions in a bottleneck system
Frette, Vidar; Hemmer, Per Christian (Journal article; Peer reviewed, 2009)Velocity and cluster distributions for particles with unidirectional motion in one dimension are studied. The particles never pass each other, like cars on a narrow road that does not allow overtaking. As a result, ...