Title: Radiation signature in opposed-flow flame spread

Authors: Subrata Bhattacharjee; Christopher P. Paolini; Fletcher Miller; Rohit Nagarkar

Addresses: Mechanical Engineering Department, SDSU, San Diego, CA 92014, USA. ' Mechanical Engineering Department, SDSU, San Diego, CA 92014, USA. ' Mechanical Engineering Department, SDSU, San Diego, CA 92014, USA. ' Mechanical Engineering Department, SDSU, San Diego, CA 92014, USA

Abstract: A radiation calculation procedure is presented for opposed-flow solid fuel flame spread. The purpose is to aid selection of different approaches for infrared flame imaging during flame spread experiments in a quiescent microgravity environment. The RADCAL and TTNH models are compared for accuracy and computational cost. The TTNH model is shown to be sufficiently accurate to calculate radiative heat flux. The RADCAL calculations suggest the ratio of signals at two prominent bands is a good candidate to detect a radiation signature. A range of flow velocities, fuel thicknesses, and environmental conditions are considered to evaluate the strength of radiative losses compared to the heat released by combustion. The results confirm the importance of radiative heat transfer in the microgravity regime, where the opposed-flow velocity can be mild or even absent, and support the conclusion that a simplified model for radiation calculation produces sufficient accuracy when compared to detailed RADCAL calculations.

Keywords: computational fluid dynamics; CFD; flame spread; RADCAL; total transmittance non-homogenous; TTNH; microgravity; radiation calculation; solid fuel flames; infrared flame imaging; quiescent microgravity; modelling; radiative heat transfer; flow velocity; fuel thickness.

DOI: 10.1504/PCFD.2012.048249

Progress in Computational Fluid Dynamics, An International Journal, 2012 Vol.12 No.4, pp.293 - 301

Published online: 25 Nov 2014 *

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