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Analytical modelling of the effect of in-depth radiation within a liquid layer in the case of a pool fire

Book Contribution - Book Chapter Conference Contribution

In this paper, we present a U+2018simplifiedU+2019 approach for the numerical modelling of the convective currents that occur within a liquid fuel in the case of a pool fire and which are induced by in-depth thermal radiation. This approach is based on the concept of U+2018effectiveU+2019 thermal conductivity, which is calculated herein based on the analytical solution of a steady-state one-dimensional heat conduction equation including a source term for in-depth radiation. This solution leads to a temperature profile which displays a horizontal liquid layer (of a given depth) that is bounded by a temperature that is higher at its bottom than its top. This thermal structure generates Rayleigh-BĂ©nard instabilities which enhance heat transfer within the liquid. This effect is modeled via an increase of the U+2018actualU+2019 thermal conductivity of the liquid by a dimensionless heat transfer number, namely the Nusselt number. The Nusselt number is calculated based on the U+2018classical expressionU+2019 of the Rayleigh number for the case of a U+2018horizontal cavity heated from belowU+2019. The paper provides the details of the derived solution for the U+2018effectiveU+2019 thermal conductivity along with examples of application to several fuels.
Book: Proceedings of the Ninth International Seminar on Fire and Explosion Hazards
Volume: 1
Pages: 693 - 703
Publication year:2019