Abstract
This paper presents experimentally measured flame lengths of pool fires (circular pan's diameter ranging from 2.2 to 20 cm) with an emphasis on the influence of buoyant and swirling flows. A recently proposed flame-length theory of pool fire, which is an extension of classical Burke-Schumann and Roper theories, is applied to explain the experimental results. The theory is based on the laminar-flame assumption and predicts with a high accuracy flame length in the laminar regime. The theory, however, tends to overestimate flame length in the turbulent regime, where the turbulence is induced by the buoyancy flow. The theory is then extended by considering a turbulent diffusion coefficient; the extended theory successfully explains the observed shift of flame-length trend in the turbulent regime in a qualitative manner.