Traditional, state-of-the-art and renewable thermal building insulation materials: An overview

Formation and evolution of distorted tulip flames

A G Gaydon and H G Wolfhard London: Chapman and Hall 1970 pp + 365 price £6 With the rapid expansion of combustion science in and over so many fields in the last decade, it is a relief to learn of a new edition of this well known book. Although the framework of this volume will be reassuringly recognizable to first edition veterans, the contents, which include the extra chapter topics of the second edition, have been thoroughly sifted to bring the frontier information up to date.

https://iopscience.iop.org/article/10.1088/0031-9112/22/3/032/pdf

Flames: Their Structure, Radiation and Temperature

Hydrogen as an energy carrier is a very promising alternative fuel in the future. Accidental hydrogen explosions remain one of the major concerns in hydrogen energy utilization and process industries. This paper summarizes recent experimental and numerical efforts towards understanding combustion wave propagation in hydrogen explosions, including flame instabilities, flame acceleration, deflagrations, and deflagration-to-detonation transition (DDT). The fundamental problems involve understanding physical mechanisms that significantly influence the dynamic flame behavior in hydrogen explosions, such as combustion/hydrodynamic instabilities, vortex motion, pressure waves and flow turbulence. Advances achieved over recent years in new experimental observations, theoretical models and numerical simulations are discussed. Future research is required to quantitatively understand flame instabilities, turbulence properties and DDT in hydrogen explosions and improve reliability of theoretical and numerical predictions for hydrogen safety applications.

Premixed flame propagation in hydrogen explosions

Eco-friendly geopolymer materials: A review of performance improvement, potential application and sustainability assessment

Correlation study between flammability and the width of organic thermal insulation materials for building exterior walls

This paper deals with thermal and fire performance evaluation of expanded polystyrene (EPS) and extruded polystyrene (XPS) in a cone calorimeter with a piloted ignition. The correlation analysis of sample thickness, heat flux (
 $$ \dot{q}^{\prime \prime } $$
 ), and experimental results is performed. It is found that the heat flux follows a linear function of the vertical distance from the standard horizontal level to the sample. An optimization ignition model is established considering the effects of sample thickness (or radiant distance). The modified ignition time (
 $$ \bar{t}_{\text{ig}} $$
 ) decreases with the increase of the sample thickness. Both t
 ig (ignition time) and $$ \bar{t}_{\text{ig}} $$
 drop as external heat flux rises. EPS’s t
 ig is more sensitive to the variation of external heat flux. Thermal thickness (δ
 P) decreases with the intensifying of heat flux, and δ
 P is in linear correlation with $$ \rho /\dot{q}^{\prime \prime } $$
 . When sample is quite thin or the irradiance level is low (2 cm-thick PS under 35 kW m−2 and 3 cm-thick EPS under 25 kW m−2), single peak heat release rate (HRR) is present. Under other situations, there are at least two peak values. For EPS, the first peak value is higher than the last, while the reverse is true for XPS (exclusive of 5 cm-thick XPS at 35 kW m−2). Both peak and mean HRR rise linearly with the increase of external heat flux. t
 ig, $$ \bar{t}_{\text{ig}} $$
 , critical heat flux and δ
 P of XPS are smaller than those of EPS, while the reverse is true for mean HRR. The ignition and heat release risk of PS drop with the decrease of external heat flux, and these hazards of XPS are higher than those of EPS.

Correlation analysis of sample thickness, heat flux, and cone calorimetry test data of polystyrene foam

An experimental study of premixed hydrogen/air flame propagation in a partially open duct

In order to explore the mechanisms of horizontal flame spread over thermal insulation foam surfaces, extruded polystyrene and expanded polystyrene foams were selected to carry out a series of experiments with different sample widths ranging from 4 to 16 cm. Temperatures in both the solid phase and the gas phase were measured, with considerable differences being found between extruded polystyrene and expanded polystyrene in their temperature profiles. Extruded polystyrene also showed a distinct pyrolysis stage, while expanded polystyrene showed a lengthy melting stage differences that may be explained from their different thermal properties. The flame spread rates of both materials first decreased and then increased with increasing sample widths. The minimum flame spread rates were at widths of 8 and 10 cm for extruded polystyrene and expanded polystyrene, respectively, resulting from the relative differences between convection and radiation heat flux, which were different for the two foams. Numerical equa...

Weiguang An

Papers

Correlation study between flammability and the width of organic thermal insulation materials for building exterior walls

Correlation analysis of sample thickness, heat flux, and cone calorimetry test data of polystyrene foam

An experimental study of premixed hydrogen/air flame propagation in a partially open duct

Theoretical and experimental study of width effects on horizontal flame spread over extruded and expanded polystyrene foam surfaces

Dynamics of premixed hydrogen/air flame in a closed combustion vessel