Flow Modeling Solutions for Homeland Security

Homeland Security has become very important to many nations over the past few years. Fluid flow modeling allows the study of "What if?" scenarios as part of threat assessment. If the scenario involves the indoor or outdoor release of toxic gases or particles, computational fluid dynamics (CFD) will predict how the toxins spread through space and time. Accurate predictions of local concentrations allow you to predict the impact of an attack. These predictions also allow you to identify the best escape routes, which is essential to response plan development and sensor placement. Other "What If?" scenarios that can be studied using CFD include dam breaks, the collapse of storage tanks and blastwaves associated with explosions or sudden gas leaks.

CFD also plays a vital part in the design of prevention systems, such as sensors, detectors, portals, and screening devices. Furthermore, it is used to design personal protection equipment, especially masks and suits. As part of preparing for an attack, CFD is used to simulate numerous scenarios in order to populate lookup tables. During an attack, real-time first responder tools collect information from the sensors and correlate it to the lookup tables to determine the most probable release points and the best escape routes.

In the aftermath of an attack, CFD is used to assess the human exposure levels near the attack site, such as estimating the spread of particulates that resulted from the collapse of the Twin Towers. CFD also guides cleanup operations, for example, it has been used to plan fumigation procedures for buildings.

Streamlines to visualize a release near Madison Square Garden. Ensight was used for postprocessing. Courtesy of the EPA