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Combustion Experiment (combustion + experiment)

Distribution by Scientific Domains

Engineering	100%

Selected Abstracts

One-sided flame spread phenomena of a thermally thin composite cotton/fiberglass fabric

FIRE AND MATERIALS, Issue 1 2005
Julie Kleinhenz
Abstract As an experimental necessity, past flame spread studies have relied on fast burning cellulosic papers. For the longer duration tests planned for the International Space Station a 50% fiberglass, 50% cotton composite fabric is better suited for the novel fuel feeding system in the compact hardware design of a current microgravity combustion experiment. The fabric's combustion characteristics in normal gravity include unexpected cases where a flame can be sustained on one side of the fuel. One-sided flames are smaller in size than their two-sided counterparts, and propagate at half the speed. Surface temperature distributions were measured using infrared imaging and indicated a high temperature region caused by the non-flammable fiberglass. Breaching the fiberglass matrix made it possible for the flame to transfer to the other side of the fuel, suggesting that the fiberglass matrix acts as a flame arrester. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Influence of reaction mechanisms, grid spacing, and inflow conditions on the numerical simulation of lifted supersonic flames

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 12 2010
P. Gerlinger
Abstract The simulation of supersonic combustion requires finite-rate chemistry because chemical and fluid mechanical time scales may be of the same order of magnitude. The size of the chosen reaction mechanism (number of species and reactions involved) has a strong influence on the computational time and thus should be chosen carefully. This paper investigates several hydrogen/air reaction mechanisms frequently used in supersonic combustion. It is shown that at low flight Mach numbers of a supersonic combustion ramjet (scramjet), some kinetic schemes can cause highly erroneous results. Moreover, extremely fine computational grids are required in the lift-off region of supersonic flames to obtain grid-independent solutions. The fully turbulent Mach 2 combustion experiment of Cheng et al. (Comb. Flame 1994; 99: 157,173) is chosen to investigate the influences of different reaction mechanisms, grid spacing, and inflow conditions (contaminations caused by precombustion). A detailed analysis of the experiment will be given and errors of previous simulations are identified. Thus, the paper provides important information for an accurate simulation of the Cheng et al. experiment. The importance of this experiment results from the fact that it is the only supersonic combustion test case where temperature and species fluctuations have been measured simultaneously. Such data are needed for the validation of probability density function methods. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Isocyanates, aminoisocyanates and amines from fires,a screening of common materials found in buildings

FIRE AND MATERIALS, Issue 6 2003
Per Blomqvist
Abstract Isocyanates, aminoisocyanates and amines were quantified from the combustion of 24 different materials or products typically found in buildings. Small-scale combustion experiments were conducted in the cone calorimeter, where generally well-ventilated combustion conditions are attained. Measurements were further made in two different full-scale experiments. Isocyanates and amino-compounds were sampled using an impinger-filter sampling system with a reagent solution of di-n-butylamine in toluene. Filter and impinger solution were analysed separately using LC-MS technique. Further the particulate distribution in the smoke gases was determined by impactor technique, and selected gaseous compounds quantified by FTIR. It was found in the small-scale that isocyanates were produced from the majority of the materials tested. The highest concentration was found for glass wool insulation, and further high concentrations were found for PUR products, particleboard, nitrile rubber and melamine. Lower concentrations were found for wood and cable-products. Amino-isocyanates and amines were generally found from PUR products only. The distribution of isocyanates between the particulate- and fluid phases varied for the different materials and a tendency to enrichment of particles was seen for some of the materials. Further, when comparing the potential health hazard between isocyanates and other major fire gases (based on NIOSH IDLH-values) it was found that isocyanates in several cases represented the greatest hazard. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Characterization of the combustion products in large-scale fire tests: comparison of three experimental configurations

FIRE AND MATERIALS, Issue 2 2001
Per Blomqvist
The storage of large amounts of polymers and other bulk chemicals is a potential hazard in the case of fire. There is at present a lack of knowledge about the implications of such fires. In particular the role of the ventilation conditions on fire chemistry has warranted investigation. A set of indoor, large-scale combustion experiments, conducted on five different materials is described in this article. The main test series was conducted using the ISO 9705 room, where both well-ventilated and under-ventilated conditions were attained by restricting the opening of the room. The degree of ventilation was determined using a phi meter. Furthermore, in addition to measuring the traditional fire-related parameters, extensive chemical characterization of the combustion products was made. Two additional series of experiments were also performed. In one series of tests the size of the enclosure was increased and the fuel was placed in a storage configuration to simulate a real storage situation. In the other test series, three of the materials were tested as large-scale open pool fires. The results from the three configurations are compared regarding yields of combustion products as a function of the degree of ventilation. For a number of toxic combustion products a clear dependence of the production on the equivalence ratio was found. Further, placing the fuel in a storage configuration did not significantly change the outcome of the combustion. Thus, the ISO 9705 room is of a size and scale that can be taken as a model for representing real-scale fires. Additionally it has been demonstrated that an advantage of the ISO 9705 room is the ability to alter the ventilation conditions. Copyright © 2001 John Wiley & Sons, Ltd. [source]