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   COLLOQUIUM OF THE LABORATORY FOR COMPUTER DESIGN OF MATERIALS
                   School of Computational Sciences
                           (CSI 898-Sec 001)
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                MATHEMATICAL MODELS OF FIRE: 
          RECREATING THE WORLD TRADE CENTER FIRES
                      Ronald G. Rehm
        Fire Research Laboratory, National Institute of 
     Standards and Technology, Gaithersburg, MD 20899

For the past two decades, scientists at the National Institute of 
Standards and Technology (NIST) in Gaithersburg Maryland have been 
developing mathematical models to simulate the behavior of fire. 
These models are based on the laws of physics. The equations for 
conservation of mass, momentum, energy and species, as well as, the 
equations for radiative transport, smoke dynamics and other physical 
processes, are solved approximately to  yield predictions of the fire 
evolution, even in complicated geometries. Many predictions have been 
compared favorably with laboratory and full-scale measurements made 
to test the quality of the predictions.

While these models were originally developed to describe indoor 
fires, they have also found extensive use in simulations of outdoor 
fires. Recently these models have been used to help recreate and 
analyze fire conditions that may have existed in the World Trade 
Center (WTC) towers before collapse. This work is expected to yield 
estimates for the thermal environment to which structural elements 
surviving the initial impact were exposed. Elevated temperatures and 
heat fluxes, for example, would be expected to reduce the strength of 
these elements!

Photographs and video footage represent evidence or "data" for 
reconstruction of the events leading to the collapse of the towers. 
New data sources are determined almost
daily, and this information, about both the exterior damage and the 
fire conditions, is used to guide and refine the modeling efforts. 
Since the interior damage and fuel distributions are unkown, we must 
guess them for each simulation. Comparison with the photographic and 
video data, then provides insight into the quality of these guesses. 
While substantial progress has been made on analyzing the WTC tower 
fires, much research remains. This talk will describe both the 
general fire modeling efforts and the application of these methods to 
the WTC tower fires.

                          Monday , April 8, 2002
                                  4:30 pm
                        Room 206, Science & Tech. I

Refreshments will be served at 4:15 PM.
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Find the schedule at http://www.csi.gmu.edu/lcdm/seminar/schedule.html