The computer model predicted that the draft curtains and, to a lesser degree the roof vents, would actually interfere with the working of sprinklers by delaying their opening and by blocking the full distribution of water from them. The experiment was designed to examine the workings of roof vents, sprinklers and draft curtains, which hang from the ceiling of large buildings, like warehouses, and are designed to funnel smoke from a fire inside the building toward the vents. McGrattan ran the program before the test burning of an actual building at the Underwriters Laboratory. (Thus, water puts out a fire by cooling, not drowning, it, while depriving a fire of oxygen smothers it.) The dynamic model takes days to run through its calculations, making it less user friendly, if more precise, than its predecessor - but it has already proved its worth. Heat causes materials, like wood, candle wax or fabrics, to release gases, which then fuel the fire in the presence of oxygen. Using the staggeringly complex equations of computational fluid dynamics, it then maps in three dimensions the fire and the flow of heated air through the room.
#OUTGUESS WEBSITE SIMULATOR#
The Fire Dynamic Simulator solves those problems by dividing a room into cubes six inches on each side, Dr. Although it can make rough calculations about the changing intensity and size of the fire over time, the program cannot determine its location in a room. Unable to model the flow of air, it cannot anticipate the behavior of fire in more complicated spaces, like rooms with exposed beams or odd shapes. Bukowski, a senior engineer at the fire research laboratory, who helped create the ''zone'' model.īut the model provides only a one-dimensional view of a room, showing the vertical distribution of hot and cooler air, not its horizontal movements. First released for use on a desktop computer in 1983, it is also widely used by fire investigators, said Richard W. The model drew on abundant data from tests of ignition temperatures and burning times of new materials.Ĭombined with another model anticipating the behavior of people in the presence of fire, this so-called ''zone'' model gave specialists a powerful tool for determining the layout of evacuation routes, as well as the placement and timing of fire alarms and sprinklers in buildings, railroad cars and planes.
But in the 1980's, researchers at the laboratory began developing a computer program that would model the behavior of fire in an enclosed space, using data on the type, amount and ignition temperatures of whatever flammable materials were present. Until now, fire codes and designs aimed at preventing such losses were based on the accumulated wisdom of firefighters, basic mathematical calculations and laboratory tests of materials, Dr. Nearly 75 percent of fire fatalities occur in flashovers, Dr. On average each year, 4,000 civilians die and 40,000 are injured in fires, primarily in their homes among firefighters, 80 to 90 die and 80,000 to 90,000 are injured. Structural fires cost the American economy about $128 billion annually in property damage, maintaining fire departments and insurance. The researchers have also used the program to predict the performance of ceiling sprinklers in fires and to explain why a sprinkler next to one already active fails to open in proper sequence, a phenomenon known as sprinkler skip.
Gann, senior research scientist at the lab.Īs part of continuing official investigations, researchers at the laboratory have already used the computer model to reconstruct fatal fires that occurred in Washington and Brooklyn in 1998. The program is the most sophisticated and powerful of its kind, said Dr. Howard Baum, designed to simulate the behavior of fire in a building in precise three-dimensional detail, and to evaluate systems for detecting and extinguishing the fire.Ĭalled the Fire Dynamic Simulator, the program is to be posted soon for distribution on the Web site of National Institute of Standards and Technology (). This fire was hypothetical, created on a computer program that Dr. Kevin McGrattan, a mathematician with the Building and Fire Research Laboratory at the National Institute of Standards and Technology in Gaithersburg, Md. ''Once you have flashover, you generally lose the structure and lives,'' said Dr.
0 kommentar(er)
