A simpler tractable contour technique to model thermal radiation from buoyant diffusion flames

This work presents an original technique based on parametric interpolation to estimate the view factor between unsteady flames and a small target. The technique was tested on a buoyant diffusion flame generated in an ethylene-fueled porous burner that emulates a pool fire. Flame images were processed to determine the flame contours in terms of parametric polynomials. A mathematical formulation based on the Stokes’ theorem was developed to estimate the view factor between the flame and a radiometer, whose contour integrals were solved numerically. These results were compared to ones obtained with the point-source method and the solid flame model, assuming the flame as a cylinder and a cone. The proposed technique captures the influence of geometry on the radiant flux field more robustly than these methods, providing estimations of thermal radiation between the point and solid flame models.