- Author
- Kitano, M. | Nagano, M.
- Title
- Smoldering Combustion of Polyurethane Foam Under Natural Convection Conditions.
- Coporate
- Tohoku Univ., Miyagi, Japan Toyota Motor Co., Aichi, Japan
- Journal
- Bulletin of Japanese Association of Fire Science and Engineering, Vol. 41, No. 2, 11-18, 1993
- Keywords
- polyurethane foams | smoldering combustion | natural convection | experiments
- Abstract
- [ABSTRACT IN ENGLISH] Experiments of smoldering in a layer of flexible polyurethane foam under natural convection conditions were conducted, and effects of the propagation direction of smolder wave toward the buoyant force (downward and upward propagation) and the fuel layer thickness were investigated on smoldering characteristics, such as the intensity of energy input to initiate smolder, minimum energy for smolder wave to completely propagate through the fuel layer, smolder velocity, and maximum reaction zone temperature. The main findings were: (1) Smolder initiation and propagation was restructed within a certain range of energy input intensity. (2) One-dimensionality of the smolder wave was fairly good for the downward propagation, but not for the upward propagation, implying an occurrence of complex secondary flow inside the layer. (3) In the middle part of the layer where end surface effects of heating or heat loss were small, smolder velocities were nearly constant and the wave seemed to propagate steaily. Downward smolder was stronger (faster smolder velocity and higher maximum temperature) than upward smolder in this region. (4) Increasing the fuel layer thickness, which further restricted air suction under natural convection conditions, decreased smolder velocity as well as maximum temperature, suggesting that the limit for self-sustaining smolder might appear for much thicker fuel layers without a forced air supply.