Firebrand transport from a novel firebrand generator - numerical simulation of laboratory experiments

Oct 22, 2026

Uploaded by asda1da

Firebrands (embers) intensify wildfires by increasing spread rates and causing ignition and destruction of houses, making accurate prediction of ember motion and new-fire ignition a priority. This study builds benchmark experiments using a novel, controllable firebrand generator, then validates a numerical firebrand-transport model against those measurements. Validation covers non-burning and burning cubiform particles at two flow speeds and tests four drag sub-models for applicability across firebrand shapes.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages37

Reading Time1 h 33 min

AccessFree to download

Abstract

Summary

Introduction

Firebrand transport from a novel firebrand generator: numerical simulation of laboratory experiments This is the Accepted version of the following publication Wadhwani, R, Sutherland, D, Ooi, A and Moinuddin, Khalid (2022) Firebrand transport from a novel firebrand generator: numerical simulation of laboratory experiments. International Journal of Wildland Fire. ISSN 1049-8001 The publisher’s official version can be found at [https://www.publish.csiro.au/wf/pdf/WF21088](https://www.publish.csiro.au/wf/pdf/WF21088)[ ](https://www.publish.csiro.au/wf/pdf/WF21088)Note that access to this version may require subscription. Downloaded from VU Research Repository [https://vuir.vu.edu.au/43615/](https://vuir.vu.edu.au/43615/) 1 Firebrand transport from a novel firebrand generator: Numerical simulation of 2 laboratory experiments 3 Running head: Experimental and numerical study of firebrand 4 R. WadhwaniA,B, , D. SutherlandB,C, A. OoiB,D, K. MoinuddinA,B, * 5 ACentre for Environmental Safety and Risk Engineering, Victoria University, Melbourne, VIC 6 3030, Australia 7 BBushfire and Natural Hazards CRC, Melbourne, VIC 3002, Australia 8 C School of Science, University of New South Wales, Canberra, ACT 2600, Australia 9 DDepartment of Mechanical Engineering, University of Melbourne, VIC 3052, Australia 10 Abstract 11 Firebrands (often called embers) increase the propagation rate of wildfires and often cause the 12 ignition and destruction of houses. Predicting the motion of firebrands and the ignition of new 13 fires is therefore of significant interest to fire authorities. Numerical models have the potential 14 to accurately predict firebrand transport. The present study focuses on conducting a set of 15 benchmark experiments using a novel firebrand generator, a device that produces controlled 16 and repeatable sets of firebrands, and validating a numerical model for firebrand transport 17 against this set of experiments. The validation is conducted for the transport of non-burning and 18 burning cubiform firebrand particle at two flow speeds. Four generic drag sub-models used to 19 estimate drag coefficients which are suited for a wide variety of firebrand shapes are verified * [Corresponding author: khalid.moinuddin@vu.edu.au](Corresponding author: khalid.moinuddin@vu.edu.au) 20 for their applicability to firebrand transport modelling. Among four, these sub-models are found 21 to be good in various degrees at predicting the transport of firebrand particles. 22 Keyword: Short-range firebrands, Lagrangian particles, Firebrand generator, Fire Dynamics 23 Simulator, Drag models; Lateral spread; Contour; Contour peak location; 24 Summary 25 A combined experimental and numerical study of firebrand transport is presented. A novel 26 firebrand generator is built to produce specific-shaped burning firebrands and measure landing 27 distributions. A physics-based model is used with four different drag sub-models to reproduce 28 experimental results and results are obtained with various degrees of fidelity. 29 Introduction 30 Firebrands are a primary cause of increased rate of fire spread inside a forest canopy and can 31 cause damage to structures located close to a forest. The whole process encompassing the 32 transport of the firebrands and the propensity to ignite surface fuels or structures is called 33 spotting. Short-range (where the firebrands travel up to 750 m) spotting is principally observed 34 inside the forest canopy where the firebrands travel mainly due to shear stress of wind, with 35 little to no lofting provided by the buoyant force of the sub-canopy fire (Cruz et al. 2015) . 36 Massive short-range spotting can increase the observed rate of fire spread up to three times, 37 compared with the rate of fire spread when the firebrands are not present; this effect is observed 38 in the 1962 Daylesford fire (McArthur 1967) . Thus, it is imperative to a

FAQs

What is the main objective of the study?

To conduct benchmark experiments using a novel firebrand generator and validate a numerical model for firebrand transport against the experimental results.

What kinds of firebrand particles and flow conditions are used for validation?

The validation is performed for non-burning and burning cubiform firebrand particles at two different flow speeds.

How are drag sub-models evaluated in the study?

Four generic drag sub-models are verified to estimate drag coefficients for a wide range of firebrand shapes, and their performance is compared for predicting firebrand transport.

Oct 22, 2026

Uploaded by asda1da