FIREBRAND ACCUMLATION ZONES IN FRONT OF STRUCTURES IN WILDLAND-URBAN INTERFACE (WUI) FIRES

Published

February 2, 2015

Author(s)

Samuel L. Manzello, Sayaka Suzuki

Abstract

It is well known that as structures are exposed to wind, stagnation planes are produced around structures. Past work by the authors demonstrated for the first-time that wind-driven firebrand showers may accumulate in these stagnation planes. While those experiments demonstrated this important phenomenon, due to the limited duration of firebrand showers of the original NIST batch feed Firebrand Generator, it was not possible to perform a more systematic study. To this end, a series of detailed experiments were performed using the recently developed NIST Continuous-Feed Firebrand Generator capable of firebrand showers of unlimited duration. Full-scale walls of varying orientation were placed downstream of the device and the wind speed was varied in increments up to 10 m/s. The experiments were conducted in the Building Research Institute’s Fire Research Wind Tunnel Facility (FRWTF). For a given wall orientation exposed to specific firebrand size/mass distribution, it was observed that wind speed influences not only the spatial location and extent of the accumulated firebrands in the stagnation plane in front of the wall, but also the nature of the smoldering combustion intensity of the accumulated firebrands. The experiments demonstrated that higher wind speeds (10 m/s) did not promote accumulation of firebrands in stagnation planes in front of walls. The data may be used to provide guidance to appropriate separation distances that combustibles should be placed near structures and is also of great use to validate CFD models of firebrand transport.

Proceedings Title

Fire and Materials 2015

Conference Dates

February 2-4, 2015

Conference Location

San Francisco, CA

Pub Type

Conferences

Keywords

WUI Fires, Firebrands

Citation

Manzello, S. and Suzuki, S. (2015), FIREBRAND ACCUMLATION ZONES IN FRONT OF STRUCTURES IN WILDLAND-URBAN INTERFACE (WUI) FIRES, Fire and Materials 2015, San Francisco, CA (Accessed April 16, 2024)