Characterization of a diffusion flame inside a scale tunnel using double stream-twin jets air curtains

•The behavior of a diffusion flame inside a scale tunnel was studied.•Thermal radiation measurements were compared to numerical predictions using the FDS.•Gray gas model and 500 solid angles are good configurations to predict experimental data with FDS.•Measurements of flame height were compared to previous correlations.•Double stream – twin jet air curtains are able to confine heat for higher injections of fuel.

In this experimental and numerical study using the Fire Dynamics Simulator (FDS) code the characterization of a diffusion flame inside a scale tunnel equipped with double stream-twin jets (DS-TJ) air curtains system is briefly described. Results of radiation and flame height were compared with theory. The FDS code has proved to be a suitable tool to predict the radiation with both gray gas assumption and 6-bands models. Gray gas model using 500 solid angles is the best option for a cheap and quick prediction. The experimental results for flame height are in good agreement with the usual zf/Df∝Q2/5zf/Df∝Q2/5 law.