LV-17-C073 -- Comparison of Smoke Management Software and Experimental Measurements of Smoke Properties during a Structural Fire ✓ Most Recent

A small-scale test section consisting of 3 m high acrylic model with a single vertical shaft was used to simulate a fire in a building. A propane burner on the first floor provided high-temperature gases that entered the shaft and moved to the upper floors via stack-effect forces. Vertical variations in the shaft pressure and temperature distribution were measured and compared with computer-generated values. The location of the Neutral Pressure Plane (NPP) was determined as well as mass flow rates of gases that moved in and out through openings in the shaft. Data was collected for an array of fire Heat Release Rates (HHR).

The experimental data were compared to the output of a smoke management software package called COSMO. The software model is based on conservation of mass, energy and momentum applied to the movement of smoke which results in a series of differential equations that are solved numerically to yield the smoke properties throughout the structure. The software consists of a detailed heat transfer model so that the temperature distribution of the smoke is predicted, and the stack effect is accurately determined.

Comparison of the experimental data and output of the software verifies the accuracy of the model and suggests that the application of the computer model can be used to design a smoke movement plan that will enhance occupant safety during a structural fire.

The software is applied to the case of a fire in a simplified building to illustrate how computer-generated results can be used to design a life safety plan in the event of a fire in a high-rise building. The program is used to calculate the size of stairwell pressurization fans and determine the effect on the fan capacity when fire escape doors are opened on various floors.

Key Words: fire safety, fire reconstruction, residential high-rise buildings, smoke management, scaling law, smoke movement software, design of fire safety plans