Intermediate Scale Flame Spread Test Apparatus for CFD Fire Model Validation

Published

March 27, 2025

Author(s)

Karen De Lannoye, Isaac Leventon

Abstract

Upward and inclined flame spread are common fire-hazard scenarios that are particularly dangerous due to their relatively high spread rate (compared to downward or lateral spread). Several previous studies have addressed upward flame spread, both in vertical [1,2] and inclined [3] configurations. Effects of melt flow [4], molecular weight of the sample [5], sample width and thickness [6] have also been studied. To advance this work, this study presents a new experimental setup that is specifically designed to obtain advanced measurements of upward flame spread for computational fluid dynamics (CFD) fire model validation and improvement. This represents a key component of the NIST Material Flammability Database [7], which contains (1) experimental measurements (mg- and g-scale tests) and automated analysis tools for material property calibration; (2) material property sets; and (3) bench-, intermediate-, and full-scale burning and fire growth experiments for CFD fire model validation. Figure 1 shows a picture of the new setup. Samples, currently 20 cm by 50 cm (in the future, up to 40 cm by 100 cm), are glued to an insulation board (50 cm by 80 cm). Additional insulation is placed on the sides of the sample so that only the front surface is exposed, avoiding flame spread over the side edges. The prepared sample is mounted on a sample carrier, which is installed on top of a load cell (Sartorius MSE 1020S, resolution 0.01 g and maximum weight 10 200 g). Samples are ignited at the bottom (lower 2 centimeters) using a well-characterized and repeatable propane line burner (1 kW of propane). After ignition, the burner is removed from the sample. The sample can be rotated, allowing testing at all angles between vertical and horizontal positions. The entire setup is located in an enclosure (1.2 m wide, 1.8 m tall), with sides covered in a fine mesh to calm the surrounding air. The setup is placed under a calorimetric hood, enabling heat release rate measurements. Cameras are installed in front of and beside the sample (see Figure 1) to measure flame height and detect possible sample deformation. A first test series was conducted on several commercially available polymethyl methacrylate (PMMA) sheets with a nominal thickness of 6 mm, including cast and extruded types, as well as black and transparent variants. Results (mass loss rate, heat release rate, and flame height) are discussed and compared for the different PMMA types, along with the influence of secondary effects such as dripping, melt flows, and deformation. The first set of experiments was conducted in a vertical orientation.

Proceedings Title

14th U. S. National Combustion Meeting

Conference Dates

March 16-19, 2025

Conference Location

Boston, MA, US

Pub Type

Conferences

Download Paper

Local Download

Keywords

Upward flame spread, HRR, Mass loss rate, PMMA

Citation

De Lannoye, K. and Leventon, I. (2025), Intermediate Scale Flame Spread Test Apparatus for CFD Fire Model Validation, 14th U. S. National Combustion Meeting, Boston, MA, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959273 (Accessed December 13, 2025)